A 33-year-old woman is found to have a palpable thyroid nodule during a routine medical checkup. A sonogram confirms the presence of a solid, 1.5-cm nodule in the right lobe of the thyroid gland. Fine needle aspirate cytology (FNA) is reported as "follicular tumor, otherwise unspecified." At surgery, a frozen section is read as follicular carcinoma. With the neck open, the surgeon can feel for enlarged jugular and peritracheal lymph nodes, and finds none. Which of the following is the most appropriate treatment? A. Enucleation of the tumor B. Right thyroid lobectomy C. Total thyroidectomy D. Total thyroidectomy plus postoperative radioactive iodine E. Total thyroidectomy, radical neck dissection, and postoperative radioactive iodine Explanation: The correct answer is D. Follicular cancers can metastasize by way of the blood stream to the liver, lung, brain, or bones. Because the tumor has rudimentary functional capability, it can be traced with and ablated by radioactive iodine; however, the tumor cannot compete successfully with normal thyroid tissue for the capture of iodine. After removal of the entire gland, the tumor becomes the most effective iodine trapper in the body. Enucleation (choice A) is never a good answer when dealing with cancer. Local recurrence would virtually be guaranteed. Lobectomy alone (choice B) would leave normal thyroid in place and thus prevent future use of radioactive iodine. Total thyroidectomy (choice C) is a correct, but incomplete, answer. Radical neck dissection (choice E) is not needed if there are no palpable nodes. Should they develop later, the procedure could be done then, or the nodes could be dealt with by means of radioactive iodine. A 68-year-old woman presents with an obviously incarcerated umbilical hernia. She has gross abdominal distention, is clinically dehydrated, and reports persistent fecaloid vomiting for the past 3 days. Although tired, weak, and thirsty, she is awake and alert and her sensorium is not particularly affected. Laboratory analysis reveals a serum sodium concentration of 118 mEq/L. Which of the following is the most likely physiologic explanation for the serum sodium? A. She has acute water intoxication B. She has been vomiting and trapping hypertonic fluids in the bowel lumen C. She has vomited and sequestered sodium-containing fluids, and has retained endogenous and ingested water D. There must be a laboratory error, because such a serum sodium level would have produced coma E. Volume deprivation leads to renal wasting of sodium Explanation: The correct answer is C. Gastrointestinal tract fluids have a sodium concentration very close to that of plasma; as they are lost (internally or externally), they should be replaced with isotonic, sodiumcontaining fluids. But that is not what patients typically do at home. Thirsty and unable to eat solid (sodiumcontaining) foods, they drink water, Coke, and tea, fluids without significant amounts of sodium, which the body avidly retains because of the severe volume depletion. Endogenous water from catabolic activity is also retained. Dilutional hyponatremia eventually develops. She does not have "water intoxication" (choice A). This term denotes abnormal water retention due to excessive water infusion at a time when there is a high level of ADH in the blood. This patient is retaining water because she is desperately volume-depleted, not because high volumes of water are being forced into her. The hyponatremia is not due to the loss of hypertonic fluid (choice B). There are no hypertonic fluids in the gut, or anywhere else for that matter. The only hypertonic fluid that we can lose is highly concentrated urine, but we usually do so as a physiologic response to save water. Yes, we often see comatose and convulsing patients when they have this much hyponatremia (choice D), but that happens when water retention is massive and fast. Slow water retention allows the brain to adapt. One can see even lower serum sodium concentrations in patients with a clear sensorium. Volume deprivation leads to renal wasting of sodium (choice E) is plain wrong. What the kidney does when there is volume depletion is to increase reabsorption of sodium, not to dump it. A 68-year-old man is brought to the emergency department with excruciating back pain that began suddenly 45 minutes ago. The pain is constant and is not exacerbated by sneezing or coughing. He is diaphoretic and has a systolic blood pressure of 90 mm Hg. There is an 8-cm pulsatile mass deep in his epigastrium, above the umbilicus. A chest x-ray film is unremarkable. Two years ago, he was diagnosed with prostatic cancer and was treated with orchiectomy and radiation. At that time, his blood pressure was normal, and he had a 6cm, asymptomatic abdominal aortic aneurysm for which he declined treatment. Which of the following is the most likely diagnosis? A. Dissecting thoracic aortic aneurysm B. Fracture of lumbar pedicles with cord compression C. Herniated disc D. Metastatic tumor to the lumbar spine E. Rupturing abdominal aortic aneurysm Explanation: The correct answer is E. Abdominal aortic aneurysms have a high incidence of rupture once they reach or exceed a size of 6 cm. Often, the first manifestation is excruciating back pain, as the blood leaks into the retroperitoneal space before the aneurysm blows out into the peritoneal cavity. The combination of a big aneurysm and sudden severe back pain should always lead to this presumptive diagnosis. Looking for orthopedic or neurologic explanations can be a deadly mistake. Dissecting thoracic aortic aneurysm (choice A) could also cause excruciating back pain, but the pain usually starts as retrosternal and later migrates down. The absence of hypertension mitigates against this diagnosis, and one would expect to see a wide mediastinum on the chest x-ray film. Fracture of the spine with cord compression (choice B) could indeed happen to someone who recently had prostatic cancer, but the symptoms would be primarily neurologic deficits from cord compression. The pain from a herniated disc (choice C) runs down the leg and is exacerbated by sneezing and coughing. Metastatic tumor (choice D) is a good bet in someone with prostatic cancer. However, the pain of bony metastasis is present for weeks or months, and is constant, dull, low grade, and worse at night—not the sudden excruciating pain of this vignette. A 72-year-old woman has a red, swollen breast. She states that the condition has been present for at least several weeks, perhaps a month or two. She has no pain or fever. The skin over the area looks like orange peel. The area is not warm to the touch, but on physical examination there is a fullness to the entire breast, with no discrete mass. Which of the following is the most likely diagnosis? A. Chronic cystic mastitis B. Inflammatory cancer of the breast C. Normal menopausal involutionary changes D. Pyogenic breast abscess E. Tuberculous or fungal breast abscess Explanation: The correct answer is B. Age is your first tip-off: the older the patient is with any kind of breast problem, the more likely it is to be cancer. The description is that of inflammatory cancer, where the permeation of skin lymphatics has given the edema, redness, fullness, and orange peel appearance. The thick, tumorladen skin actually masks the underlying mass, which is felt as "fullness" rather than a discreet lump. Chronic cystic mastitis (choice A) happens to younger women (aged 20-40) with recurrent pain linked to the menstrual cycle. Menopause (choice C) shrinks the breast and makes it more fat than stroma, but it does not make it red and swollen. Pyogenic abscess (choice D) happens almost exclusively to lactating women. At age 72, we know that is not happening. Tuberculosis or fungus (choice E) is our usual guess when an abscess is not hot and tender. However, apart from their rarity in the U.S., such thoughts here would detract from the compelling dictum that a red, swollen breast in an old woman is cancer until proven otherwise. A 39-year-old woman completed her last course of postoperative adjuvant chemotherapy for breast cancer 6 months ago. She now comes to the clinic complaining of constant back pain for about 3 weeks. She is tender to palpation over two well-circumscribed areas in the thoracic and lumbar spine. Which of the following is the most appropriate next step in management? A. CT scan of the trunk B. Needle biopsy of the tender spots C. Radionuclide bone scan D. Sonogram of the affected areas E. X-ray films of the affected areas Explanation: The correct answer is C. The most sensitive test to detect early bone metastasis is the radionuclide scan. In a woman who recently had cancer of the breast, we have to suspect bony metastasis when bone pain develops. CT scan (choice A) would be more expensive and less sensitive. Needle biopsy (choice B) is invasive and not the first thing to do. Sonogram (choice D) is superb for many other things, but not to detect early bone metastasis. X-ray films (choice E) will be done after the scan if the radionuclide "lights up." The radionuclide scan is very sensitive, but not terribly specific. Once it lights up, we have to rule out other radiologically obvious bony problems that might have triggered the positive scan. A young mother complains of pain along the radial side of the wrist and the first dorsal compartment. She relates that the pain is often caused by the position of wrist flexion and simultaneous thumb extension that she assumes to carry the head of her baby. On physical examination, the pain is reproduced by asking her to hold her thumb inside her closed fist, and then forcing the wrist into ulnar deviation. Which of the following is the most likely diagnosis? A. Acute and chronic bursitis B. Carpal tunnel syndrome C. Hairline unrecognized fracture of the carpal navicular (scaphoid) bone D. Palmar fascial contracture (Dupuytren's contracture) E. Tenosynovitis of the abductor or extensor tendons of the thumb (De Quervain's tenosynovitis) Explanation: The correct answer is E. The clinical presentation is classic for De Quervain's tenosynovitis, including the positive Finkelstein sign (the pain reproduced by ulnar deviation to stretch the affected tendons). Bursitis (choice A) occurs where there are bursa; thus, the classic locations are places in which tendons or muscles pass over bony prominences. Carpal tunnel syndrome (choice B) affects young women, such as this patient, but the presentation is one of numbness along the innervation pattern of the entrapped median nerve. Fractures of the carpal navicular bone (choice C) often go unrecognized, but they occur when someone falls on an outstretched hand. The classic physical finding is pain with palpation over the anatomic snuff box. Dupuytren's contracture (choice D) produces inability to fully open and extend the hand, and it typically happens to older men of Scandinavian descent. A 68-year-old man is brought to the emergency department following a high-speed automobile accident. He is alert and complains of chest pain and mild back pain. His blood pressure is 80/60 mm Hg. Chest x-ray shows a widened mediastinum, tracheal deviation, bronchial displacement, and loss of the aortic knob. Which of the following is the most likely diagnosis? A. Cardiac tamponade B. Myocardial contusion C. Pulmonary contusion D. Tension pneumothorax E. Traumatic aortic rupture Explanation: The correct answer is E. This patient has a traumatic aortic rupture, which is the most common cause of immediate death following a motor vehicle accident. Deceleration causes twisting of the aorta and may lead to rupture. Up to 90% of the individuals die at the scene, however a high index of suspicion and early intervention may save the remaining few. The symptoms include chest pain, back pain, and hypotension. Angiography is the gold standard and immediate surgery is mandatory. X-ray findings include widening of the mediastinum, alteration of the aortic knob, pleural cap, tracheal deviation, bronchial displacement, and esophageal deviation. Cardiac tamponade (choice A) often results from penetrating trauma near the heart and is caused by a fluid collection within the pericardium. The clinical features include hypotension, distended neck veins, pulsus paradoxus, and distant heart sounds. Pericardiocentesis is the treatment. Myocardial contusion (choice B) is most commonly seen when there is a direct blow to the chest wall. Findings include right ventricular dysfunction, arrhythmias, and an elevation of creatine kinase. An echocardiogram may document ventricular wall motion abnormalities. Pulmonary contusion (choice C) is a hemorrhage into the pulmonary parenchyma. It is characterized by dyspnea and hypoxia. Tension pneumothorax (choice D) occurs when air is trapped within the pleural space and leads to an increase in the intrathoracic pressure. Findings include jugular venous distention, hypotension, tracheal deviation, and a mediastinal shift. Tension pneumothorax often occurs following blunt trauma. Treatment is with needle thoracocentesis. A 52-year-old nurse seeks medical retirement because of a "heart condition." She complains of disabling attacks of tachycardia and palpitations. The physical examination and ECG studies confirm that indeed her pulse is between 100 and 105/min at all times, and she is in and out of atrial fibrillation. It is also noted that she is fidgety and constantly moving, and various examiners remark that she arrives for tests lightly dressed when it is rather cold outside. Thyroid function studies show elevated free thyroxine (T4) and undetectable levels of thyroid stimulating hormone (TSH). Her thyroid gland is not clinically enlarged or tender. Which of the following is the most appropriate next step in diagnosis? A. Fine needle aspiration cytology of the thyroid gland B. MRI of the pituitary area C. Radioactive iodine uptake D. Serum levels of C peptide E. Serum levels of triiodothyronine (T3) Explanation: The correct answer is C. It has been established clinically and by the laboratory that this patient is hyperthyroid, but the thyroid gland does not seem to be abnormal. The circumstances suggest that self-administration of thyroid hormone for secondary gain (e.g., weight loss) is a possibility. Radioactive iodine uptake should be high if her gland is indeed hyperfunctioning, but it will be near zero if it is suppressed by the exogenous hormone. Malignancy is not an issue; thus, fine needle aspiration (choice A) does not have a role. High thyroid function with undetectable levels of TSH excludes the pituitary as the source of the problem. Thus, there is no reason to investigate it as suggested in choice B. C peptide (choice D) is indeed used to ferret out hormonal self-administration, but it distinguishes endogenous from exogenous insulin, not thyroid hormone. T3 (choice E) needs to be determined when clinical signs of hyperthyroidism coexist with normal levels of T4. A 7-year-old boy passes a large, bloody bowel movement. He is hemodynamically stable, and he has a hemoglobin of 14 g/dL. Nasogastric aspiration yields clear, greenish fluid. Physical examination, including anoscopy, is unremarkable. Which of the following is the most appropriate next diagnostic test? A. Celiac arteriogram B. Colonoscopy C. Radioactively labeled technetium scan D. Radioactively tagged red cell study E. Upper gastrointestinal endoscopy Explanation: The correct answer is C. In this age group, with no obvious anal pathology and negative gastric aspirate, the leading cause of gastrointestinal bleeding is Meckel's diverticulum. The specific source is ulceration of the normal ileal mucosa by acid produced by gastric mucosa in the diverticulum. The technetium scan identifies that ectopic gastric mucosa. Arteriogram (choice A) as a diagnostic step is a very invasive study that is appropriate only for very large hemorrhage (>2 mL/min) with clear gastric aspirate. An arteriogram may also be indicated for therapy (embolization) in severe gastrointestinal bleeding. Colonoscopy (choice B) would not identify the Meckel's diverticulum. Colonoscopy is often needed in the older patient with lower gastrointestinal bleeding, in whom the source of the hemorrhage is likely to be polyps, cancer, diverticula, or angiodysplasia. A tagged red cell study (choice D) is often used as a prelude to an arteriogram in patients with substantial lower gastrointestinal bleeding. Upper gastrointestinal endoscopy (choice E) would have been appropriate if the gastric aspirate had produced blood. A 31-year-old male immigrant from India is found on a routine physical examination to have a single, 2-cm nodule in the right lobe of his thyroid gland. The mass is firm, moves up and down with swallowing, and is not tender. The skin of his face and neck is pitted with multiple scars, which suggest smallpox; however, he explains that the scars are due to very severe acne that he had as a youngster, for which he eventually received external beam radiation therapy at the age of 14. His thyroid function tests are normal, and a fine needle aspiration (FNA) cytology of the mass is read by the pathologist as "indeterminate." Which of the following is the most appropriate next step in management? A. No further care is needed B. Thyroid function tests should be repeated yearly C. Thyroid scan and sonogram are needed D. FNA should be repeated until it can be read as benign or malignant E. Thyroid lobectomy Explanation: The correct answer is E. The patient is at high risk for thyroid cancer (young, male, with a single nodule and a history of radiation), and a reading of "indeterminate" in an FNA is a surgical indication. No further care (choice A) is totally wrong. It assumes that normal thyroid function means there is nothing wrong with the thyroid, when in fact thyroid cancer almost never alters thyroid function. This choice also assumes that if an FNA is not read as cancer, the patient does not have that disease. Focusing on function (choice B) as the criterion to do something is wrong for the same reasons. Thyroid scan and sonogram (choice C) were formerly valuable criteria to select surgical candidates (cold solid nodules meant a high risk of cancer), but the FNA provides a higher yield of malignancy in resected specimens, and thus has rendered the other tests obsolete for this purpose. Repeating the FNA (choice D) assumes that, given more cells, the pathologist should be able to distinguish benign from malignant. The pathologist has no trouble recognizing malignant features in papillary, medullary, or anaplastic cancers of the thyroid, but cannot do so with follicular neoplasms. Follicular adenoma and follicular carcinoma require a look at the entire specimen to tell them apart. A 42-year-old woman hit her breast with a broom handle while doing housework. She noticed a lump in that area at the time, and 1 week later the lump was still present. She then sought medical advice. On physical examination, she has a 3-cm, hard mass deep inside the affected breast, and some superficial ecchymosis over the area. Which of the following is the most appropriate next step, or steps, in management? A. Reassess in about 2 months, with no specific therapy B. Hot packs, analgesics, and surgical evacuation of the hematoma C. Mammogram, and no further therapy if the report does not identify cancer D. Mammogram and biopsy of the mass E. Mastectomy Explanation: The correct answer is D. Although the history of trauma might suggest a hematoma or fat necrosis, it is well known that trivial trauma sometimes brings to the attention of the patient an area of the body that had not been examined before. A breast mass in a 42-year-old woman requires a mammogram and biopsy. Waiting 2 months (choice A) would be unacceptable for a potential cancer. Hot packs and analgesics (choice B) on the assumption that this is a hematoma would also delay the diagnosis if a cancer is present. Furthermore, if this is indeed a hematoma one would not necessarily want to drain it. Choice C is incorrect because the mammogram is an adjunct to the biopsy of a breast mass, not a substitute for it. The two studies are complementary. Mastectomy (choice E) is too radical a step before a diagnosis has been established. A 22-year-old convenience store clerk is shot once with a .38 caliber revolver. The entry wound is in the left midclavicular line, 2 inches below the nipple. There is no exit wound. He is hemodynamically stable. A chest x-ray film shows a small pneumothorax on the left, and demonstrates the bullet to be lodged in the left paraspinal muscles. In addition to the appropriate treatment for the pneumothorax, which of the following will this patient most likely need? A. Barium swallow B. Bronchoscopy C. Extraction of the bullet via local back exploration D. Extraction of the bullet via left thoracotomy E. Exploratory laparotomy Explanation: The correct answer is E. Although this vignette describes a gunshot wound of the chest, we must remember that the chest and the abdomen are not stacked up like pancakes. There is a dome – the diaphram – that separates them, and thus an area where chest and abdomen overlap. Any gunshot wound below the nipples involves the abdomen, and such is the case here. The management of all gunshot wounds of the abdomen requires exploratory laparotomy. Barium swallow and bronchoscopy (choices A and B) are indicated if there are signs suggestive of injury to those organs (coughing up blood, spitting up blood), or if the anatomic trajectory of the bullet puts the track in their vicinity. Here, we have an entry wound on the left and a bullet lodged on the left: the midline has not been crossed. Taking out the bullet (choices C and D) is unnecessary if the missile is not pressing on some vital structure. A bullet embedded in a muscle can be left there. A 66-year-old man with diabetes and generalized arteriosclerotic occlusive disease notices a gradual loss of erectile function over several years. Initially, he can get erections, but they do not last long enough. Later, he notices a decrease in the quality of his erections, and more recently he becomes, by his own criteria, completely impotent. He has occasional, brief nocturnal erections, but "he can never get an erection when he needs one." Which of the following is the most appropriate initial step in management? A. Psychotherapy B. Pharmacologic therapy C. Erectile nerve reconstruction D. Implantable penile prosthesis E. Pudendal artery revascularization Explanation: The correct answer is B. This patient has organic impotence, but it is not related to trauma for which surgical reconstruction would be indicated. His remaining function can be augmented with sildenafil (Viagra®). Psychotherapy (choice A) is the thing to do for psychogenic impotence, which has a sudden onset rather than the gradual development described in this case. Nerve damage (as suggested in choice C) is the culprit in impotence following pelvic surgery (not the case here). As of now, there is no effective way to reanastomose those invisible little nerve fibers. Penile prosthesis (choice D) is always the last option, never the first one. Once a prosthesis is inserted, the normal erectile mechanism is destroyed forever. Had the history been that of a young man becoming impotent after a motorcycle accident, a vascular lesion would have been the likely problem, and a reconstruction (choice E) would be the thing to do. A 14-year-old boy dives into the shallow end of a swimming pool and hits his head against the bottom. When he is rescued, he shows a complete lack of neurologic function below the neck. He is still breathing on his own, but he cannot move or feel his arms and legs. The paramedics carefully immobilize his neck for transportation to the hospital, and they alert the emergency department to his impending arrival. Once there, which of the following would most likely have an immediate benefit for this patient? A. Hyperbaric oxygenation B. IV antibiotics C. IV high-dose corticosteroids D. Massive diuresis induced by loop diuretics. E. Surgical decompression of the cord Explanation: The correct answer is C. There is some evidence that high-dose corticosteroids administered as soon as possible after the injury will result in a better ultimate outcome. Although the true medical value of this observation may be debatable, there is a legal imperative to use the treatment, which offers some hope and has not been shown to be detrimental. Hyperbaric oxygenation (choice A) has no role in the acute management of neurologic injuries. Antibiotics (choice B) are likewise unlikely to affect the course of events in a case like this. Although diuresis (choice D) is part of the therapy used to decrease intracranial pressure, the agent of choice is mannitol, and the indications do not include spinal cord injury. Surgical decompression (choice E) might be done, but the decision is individualized depending on the findings on MRI. Not all patients are automatically and immediately taken to the operating room. After a grand mal seizure, a 32-year-old epileptic woman notices pain in her right shoulder, and she cannot move it. She goes to a minor emergency clinic, where she has a limited physical examination and anteroposterior (AP) x-ray films of her shoulder. The films are read as negative, and she is diagnosed as having a sprain and given pain medication. The next day, she still has the same pain and is unable to move her arm. She comes to the emergency department holding her arm close to her body, with her hand resting on her anterior chest wall. Which of the following is the most likely diagnosis? A. Acromioclavicular separation B. Anterior dislocation of the shoulder C. Articular cartilage crushing D. Posterior dislocation of the shoulder E. Torn teres major and minor muscles Explanation: The correct answer is D. The mechanism of injury (massive contraction of all muscles in the area) and the missed diagnosis on a single view AP x-ray film are classic for posterior dislocation of the shoulder. Axillary view x-ray films are needed to make the diagnosis. Acromioclavicular separation (choice A) would have been obvious on physical examination and on the x-ray film taken Anterior dislocation (choice B) is far more common than posterior dislocation. However, it happens with regular trauma, has a very typical posture where the arm is held close to the body but the forearm and hand are rotated out as if ready to shake hands, and is easily seen on x-ray films. Crushing of the articular cartilage (choice C) and tearing of shoulder girdle muscles (choice E) are not common injuries following seizures. A group of illegal immigrants is smuggled across the border in a closed metal truck in the middle of summer. When apprised by radio that the border patrol is on their trail, the smugglers abandon their charges in the middle of the desert, in the locked truck, with little water to drink. The victims are found and rescued 5 days later. One of them is brought to the emergency department, awake and alert, with obvious clinical signs of severe dehydration and a serum sodium concentration of 155 mEq/L. Which of the following would be the best choice and rate of IV fluid administration? A. 5 L of 5% dextrose in water (D5W) over 2-3 days B. 5 L of D5W over 5-10 hours C. 5 L of 5% dextrose in half normal saline (D5 1/2 NS) over 5-10 hours D. 10 L of D5 1/2 NS over 5-10 hours E. 10 L of normal saline over 2-3 days Explanation: The correct answer is C. A rough guideline to quantify water loss is that every 3 mEq/L that the serum sodium concentration is above normal, represents about 1 L of water deficit. With a value of 155, we can assume a water deficit of about 5 L. There is no advantage to the patient in remaining severely volume contracted for several days, thus the replacement should aim for correction in a matter of 5-10 hours rather than 2 or 3 days. However, because his loses were incurred slowly (over 5 days), his brain has had a chance to adapt to the tonicity change (he is indeed awake and alert). Thus, the tonicity correction should not happen with the same speed with which the volume is going to be corrected. That delay is achieved by choosing a fluid that is not pure water, but one that has some sodium in it to dampen the effect on tonicity. Half normal saline is a good choice. 5 L of D5W over 2 or 3 days (choice A) would be safe from the viewpoint of slowly correcting the tonicity, but it would unnecessarily prolong the state of volume depletion. 5 L of D5W over 5-10 hours (choice B) could well be deadly, because it would revert the tonicity to normal at a rate too fast for the brain to follow. Choices D and E budget a volume replacement well beyond what is needed. Neither would be lethal, because D5W is not used, but neither of them is the best answer. A football player is tackled, and he develops severe knee swelling and pain. On physical examination with the knee flexed at 90 degrees, the leg can be pulled anteriorly, like a drawer being opened. A similar finding can be elicited with the knee flexed at 20 degrees by grasping the thigh with one hand, and pulling the leg with the other. Which of the following is the most likely injured structure? A. Anterior cruciate ligament B. Lateral collateral ligament C. Medial collateral ligament D. Medial meniscus E. Posterior cruciate ligament Explanation: The correct answer is A. Swelling of the knee after trauma usually denotes the presence of a significant injury. The tests described (anterior drawer and Lachman test) are classic for an injury to the anterior cruciate ligament. The lateral collateral ligament (choice B), if disrupted, would allow the leg to be bent inward to a greater extent than normally possible (varus test). The medial collateral ligament (choice C), when injured, would produce the opposite findings: the leg could be bent outward more than the normal leg (valgus test). The medial meniscus (choice D), when injured, produces loose intraarticular bodies and locking of the knee. The posterior cruciate ligament (choice E) is much less commonly injured than the anterior cruciate. When it is injured, it produces the very opposite findings to those described in the vignette: the leg could be pushed backward, as if a drawer was being closed rather than opened. In a rollover car accident, a 42-year-old woman is thrown from the car. The car subsequently lands on her and crushes her. On physical examination in the emergency department, it is determined that she has a pelvic fracture, which is confirmed by portable x-rays done as she is being resuscitated. Her initial blood pressure is 50/30 mm Hg, and her pulse is 160/min and barely perceptible. Thirty minutes later, after 2 L Ringer's lactate and 2 U packed cells have been infused, her pressure is only 70/50 mm Hg, and her pulse is 130/min. A sonogram done in the emergency department shows no intra-abdominal bleeding, and a diagnostic peritoneal lavage confirms that there is no blood in the abdomen (the recovered fluid is pink, but not grossly bloody). Rectal and vaginal exams show no injuries to those organs. There is no blood in her urine. Which of the following is the most appropriate next step in management? A. Packing of the vagina and rectum B. Angiographic embolization of torn veins C. External fixation of the pelvis D. Open reduction and internal fixation of the pelvis E. Exploratory laparotomy with pelvic dissection and hemostasis Explanation: The correct answer is C. This is actually a terrible situation, with no easy way out. Pelvic fractures can bleed massively, and often the source is torn veins that are not easily controlled. Minimizing the motion of the bone fragments by external fixation can be helpful, and it will not make the situation worse. Packing the vagina or rectum (choice A) would help if bleeding originated in those organs, but they cannot reach the source of bleeding in this case. Angiography (choice B) can be very helpful when arteries are torn. It cannot do the same for veins. Opening the fractured area (choice D) would lose the tamponade effect and would not help control the bleeding. And as for the surgeons coming to the rescue (choice E), this is one place in which the high and mighty are routinely humbled. Opening the pelvic hematoma loses the tamponade effect, and once into the thick of things, pelvic veins bleed massively and are not easily controlled. It is best to stay out of these situations. A 61-year-old man comes in because of colicky abdominal pain and vomiting of 3 days' duration. On physical examination, he is moderately distended and has high pitched hyperactive bowel sounds and a 5-cm tender groin mass. On direct questioning, he explains that he has had that bulge for many years, but has always been able to "push it back in" when he lies down. For the past 3 days, however, he has been unable to do so. He has a temperature of 38.9 C (102 F) and a white blood cell count of 12,500/mm3. Which of the following is the most appropriate management at this time? A. A sonogram of the mass B. A trial of nasogastric suction and IV fluids for a few days C. Insertion of a long rectal tube via sigmoidoscopy D. Manual reduction of the hernia, followed by a period of observation E. Urgent surgical intervention Explanation: The correct answer is E. The clinical picture is that of a strangulated inguinal hernia. If he only had the tender mass without signs of intestinal obstruction, he might have omentum trapped. If he had the intestinal obstruction without fever, leukocytosis, and the tender mass, he could be obstructed but not strangulated. But, the combination that he has is clearly that of obstruction with strangulation. He needs urgent surgery. A sonogram to make a diagnosis (choice A) might be appropriate for a mass without signs of obstruction, if we could not clinically be sure that it was a hernia. Nasogastric suction and IV fluids (choice B) is the standard approach for obstruction due to adhesions, when there are no signs suggestive of strangulation. We do not operate for adhesions (they form again), but do so only to rescue the bowel that is trapped. In hernias, on the other hand, we want not only to rescue the bowel but also to repair the hernia. A long rectal tube (choice C) is used in Ogilvie's syndrome or volvulus, but not in strangulated hernias. Manual reduction (choice D) would actually be dangerous in this case, as it might force a dead segment of bowel into the abdomen, increasing morbidity and delaying definitive treatment. If he had no fever, no leukocytosis, and no tenderness, such an approach might be justified to gain time for an elective, nonrushed hernia repair. A previously healthy, intoxicated, 19-year-old man is driving a car without using a seat belt. He crashes the car into the back of a parked truck. In the process he slams his abdomen into the steering wheel and ruptures his spleen. Which of the following is the most important problem associated with this type of injury? A. Bacteremia B. Electrolyte abnormalities C. External blood loss D. Internal blood loss E. Peritonitis Explanation: The correct answer is D. The spleen is a highly vascularized organ, and is vulnerable to traumatic rupture. This can occur "spontaneously" (i.e. with minimal trauma such as falling against a table or even overly vigorous palpation during a physical examination) in patients with an enlarged spleen due to disease (e.g., leukemias, autoimmune diseases with red cell sequestration in the spleen, or as a complication of portal hypertension). Alternatively, splenic rupture can occur in previously normal individuals who have severe trauma to the abdomen. In either case, the heavily vascularized spleen is usually unable to stop (often massively) bleeding internally. Emergency splenectomy is indicated to control the bleeding. Bacteremia (choice A) and peritonitis (choice E) are much less of a risk in splenic rupture than in rupture of a hollow viscus such as the colon, since the spleen is usually sterile. Electrolyte abnormalities (choice B) can develop secondarily to the ischemia produced by severe blood loss; these are much less critical than the blood loss itself and will often correct spontaneously with adequate replacement of blood. External blood loss (choice C) is often insignificant in injuries such as this. A 56-year-old man develops slow, progressive paralysis of the facial nerve on one side. It took several weeks for the full-blown paralysis to become obvious, and it has been present now for 3 months. It affects both the forehead and the lower face. He has no pain anywhere, and no palpable masses by physical examination. Which of the following is the most likely diagnosis? A. Bell's palsy B. Facial nerve tumor C. Hemorrhagic stroke D. Parotid gland cancer E. Pleomorphic adenoma of the parotid gland Explanation: The correct answer is B. Slowly developing paralysis on one side is suggestive of a tumor. Since there are no physical findings to place the tumor in the parotid gland, it must be impinging on the nerve itself at a more proximal location. Bell's palsy (choice A) has sudden onset, rather than gradual development. Hemorrhagic stroke (choice C) would have occurred suddenly, with an excruciating headache. A parotid cancer (choice D) would have been palpable by physical examination and would have produced pain. Pleomorphic adenoma (choice E) would also have been palpable, and such tumors almost never produce facial nerve paralysis. A young man is shot with a .45 caliber revolver, point blank in the lower abdomen, just above the pubis. The entrance wound is at the midline, and there is no exit wound. X-ray films show the bullet embedded in the sacral promontory, to the right of the midline. Digital rectal examination and proctoscopic examination are negative, but he has gross hematuria. He is hemodynamically stable. Which of the following is the most appropriate next step in management? A. CT scan of the abdomen B. Intravenous pyelogram C. Retrograde cystogram D. Diagnostic peritoneal lavage E. Exploratory laparotomy Explanation: The correct answer is E. He has an obvious indication for exploratory laparotomy: a gunshot wound to the abdomen. He also has evidence of injury to the urinary bladder, but that will be dealt with at the same time that other intraabdominal injuries are found and repaired. CT scan (choice A) would not change the surgical approach and the surgical indication. CT scan is called for in cases of blunt trauma to diagnose intraabdominal bleeding and to identify intraabdominal injuries. Intravenous pyelogram (choice B) would indeed show the bladder injury, as would a retrograde cystogram (choice C). However, we already know clinically that there is a bladder injury: we know the trajectory of the bullet and we have blood in the urine. Diagnostic peritoneal lavage (choice D) is used to diagnose intraabdominal bleeding in blunt trauma, when the patient is not stable enough to be taken to the CT scanner. In many centers the diagnostic peritoneal lavage has been replaced by sonogram done in the emergency department by the trauma team. A 33-year-old woman is undergoing a diagnostic work-up because she appears to have Cushing syndrome. She has elevated levels of cortisol, which are not suppressed when she is given high-dose dexamethasone. ACTH levels are greater than 200 pg/ mL. A chest x-ray film shows a central, 3-cm round mass on the hilum of the right lung. Bronchoscopy and biopsies confirm a diagnosis of small cell carcinoma of the lung. Which of the following is the preferred treatment for this woman? A. Bilateral adrenalectomy B. General support only C. Pneumonectomy D. Radiation and chemotherapy directed at the lung cancer E. Trans-sphenoidal hypophysectomy and pulmonary lobectomy Explanation: The correct answer is D. The endocrine workup is indicative of ectopic ACTH production, and the obvious site is small cell carcinoma of the lung. The lung cancer is what is going to kill this woman, not the endocrine manifestations of the tumor. Although small cell carcinoma of the lung is rarely cured, longer survival can be obtained with radiation and chemotherapy. Adrenalectomy (choice A) would address the endocrine problem by depriving the ectopic ACTH of its target gland. But, as pointed out above, the lethal disease here is the lung cancer. General support only (choice B) would lead to death in about 2 months. Radiation and chemotherapy can prolong survival by approximately 2 years. Pneumonectomy (choice C) is not the treatment for small cell carcinoma of the lung. It is the appropriate treatment for resectable and potentially curable non?small cell cancers of the lung. The combination of hypophysectomy and lobectomy (choice E) is wrong for several reasons. Pituitary microadenomas suppress with high-dose dexamethasone, and their production of ACTH is typically much lower than that seen in ectopic disease (i.e., <200 pg/mL). Thus, this woman does not need pituitary surgery. As far as the lung is concerned, surgery is not the treatment for small cell carcinoma, and lobectomy would not be applicable for a central, hilar tumor. In the course of a robbery, a young woman is stabbed repeatedly. On arrival at the emergency department, she is shivering and asks for a blanket and a drink of water; she is noted to be pale and perspiring. Her blood pressure is 72/50 mm Hg and her pulse is 130/min. Her neck and forehead veins are large and distended. A quick initial survey reveals entry wounds in her left chest and upper abdomen. She has bilateral breath sounds and a scaphoid, nontender abdomen. As IV infusions of Ringer's lactate are started, her systolic blood pressure drops further to 40 mm Hg, no distal pulses can be felt, and she loses consciousness. Her central venous pressure at that time is 28 cm H2O. Which of the following is the most appropriate next step in management? A. Chest x-ray to direct further therapy B. Bilateral chest tubes C. Diagnostic peritoneal lavage D. Evacuation of the pericardial sac E. Crash laparotomy in the emergency department to clamp the aorta Explanation: The correct answer is D. The diagnosis of pericardial tamponade should be obvious. The patient has the type of chest wound that can produce it, and the very high central venous pressure to prove it. Evacuation of the blood that is preventing normal ventricular filling will produce instant improvement. Later, she will need repair of the heart wound that is probably the source of the pericardial blood and may also need exploratory laparotomy. A chest x-ray (choice A) would never be ordered in a dying patient. This patient is in trouble, and she needs instant action based on a clinical diagnosis. She would die while waiting for an x-ray. Chest tubes (choice B) have nothing to offer when there are bilateral breath sounds. In this case, the patient probably does not have a tension pneumothorax to account for the shock and the high venous pressure. Diagnostic peritoneal lavage (choice C) assumes that the reason for the deterioration is intraabdominal bleeding. With a very high central venous pressure, it is not a reasonable conclusion. Clamping the aorta (choice E) assumes that she is bleeding to death. She may be bleeding, but if that were the cause of her present predicament, her central venous pressure would be zero, or near zero. On the 5th postoperative day, it is noticed that large amounts of clear, pink, salmon-colored fluid are soaking the wound dressings of a patient who had a negative exploratory laparotomy for a stab wound of the abdomen. The laparotomy was done through a midline supraumbilical and infraumbilical incision. When seen by the surgical staff, the patient is lying in bed in the supine position, with the dressings removed. In the dim light of his hospital room, the incision appears intact and not particularly red or inflamed, but there are indeed traces of the clear pink fluid on his skin. He has no specific complaints. He is still NPO and on IV fluids, but has already been passing gas per rectum, and plans had been made to feed him today. The abdomen is not distended, and he has normal bowel sounds. He is afebrile. Which of the following is the most appropriate next step in management? A. Culture the pink fluid and start empiric antibiotic therapy B. Gently probe the wound at several points until pus is found and drained C. Help the patient out of bed and have him walk to the examining room for proper inspection of the wound D. Stop plans for oral feedings and start total parenteral nutrition E. Tape the wound securely, bind the abdomen, and avoid events that would suddenly increase his intra-abdominal pressure Explanation: The correct answer is E. The situation described is that of a wound dehiscence that has not yet progressed to a wound evisceration. The former can be dealt with at leisure, if the latter is avoided. He will eventually require re-closure, but it can be done whenever it is most convenient. Cultures and antibiotics (choice A) assume the pink fluid to be a sign of infection. It is not. It is normal peritoneal fluid (with a trace of blood still in it from the recent surgery) that is seeping out through the unhealed wound. Probing (choice B) will not produce pus, but it might hasten the dreaded evisceration. He is afebrile, and the wound is not red. Clear pink salmon-colored fluid means dehiscence, not infection. Getting the patient out of bed (choice C) is the last thing you want to do. If this advice were followed, the person helping the patient would soon be looking at a handful of small bowel as it comes rushing out of the belly. The fluid described is not bowel contents; this is not a fistula. There is no need to go to parenteral nutrition (choice D). A 57-year-old alcoholic man is being treated for acute hemorrhagic pancreatitis. He was in the intensive care unit for 1 week, where he required chest tubes for pleural effusions and was on a respirator for several days. Eventually, he improved sufficiently to be transferred to the floor. Three days after leaving the unit, and about 2 weeks after the onset of the disease, he spikes a fever and develops leukocytosis. Which of the following developments do these recent findings most likely suggest? A. Chronic pancreatitis B. Pancreatic abscess C. Pancreatic pseudocyst D. Pelvic abscess E. Subphrenic abscess Explanation: The correct answer is B. A very common complication of hemorrhagic pancreatitis, and often the reason for the demise of the patient, is the development of a pancreatic abscess. The timetable is usually about 10-14 days from the onset of the disease, and the initial manifestations are fever and leukocytosis. Chronic pancreatitis (choice A) develops after several years of recurrent attacks of pancreatitis, and is characterized by steatorrhea, diabetes, and constant pain. Pancreatic pseudocyst (choice C) is another potential complication of pancreatitis, but the manifestations are related to pressure symptoms from the fluid collection, there is no fever or leukocytosis, and the timetable for development is about 6 weeks from the onset of the disease. Pelvic abscess (choice D) and subphrenic abscess (choice E) are indeed in the differential diagnosis, as they also show up with fever and leukocytosis some 10-14 days from the original problem. But, the original problem for these patients is usually an infectious process in the abdomen, e.g., a ruptured appendix or a perforated viscus. If the problem began with pancreatitis, and then there are signs of sepsis, the pancreas is the logical place to harbor the pus. While running to catch a bus, and old man twists his ankle and falls on his inverted foot. Anteroposterior (AP), lateral, and mortise x-ray films show displaced fractures of both malleoli. Which of the following would be the preferred form of treatment? A. Closed reduction and casting B. Skeletal traction C. Open reduction and internal fixation D. Replacement with a metal prosthesis E. Fusion of the ankle joint Explanation: The correct answer is C. Precise alignment of the displaced fragments is needed to ensure that the tight mortise of the ankle joint is restored. Closed reduction and casting (choice A) is unlikely to provide the necessary realignment. Skeletal traction (choice B), in general, is indicated only in areas of the body where strong muscle groups pull broken bones into unacceptable positions. Artificial joints are usually used for advanced articular disease. In the trauma setting, replacement with a prosthesis (choice D) is as a rule reserved for fractures where avascular necrosis is predictable. Fusion of a joint (choice E) is the ultimate step when everything else has failed. It would not be the first choice for a relatively common fracture. Several months after sustaining a crushing injury to his arm, a patient complains bitterly about constant, burning, agonizing pain in that arm, that does not respond to the usual analgesic medications. The pain in his arm is aggravated by the slightest stimulation of the area, such as rubbing from the shirt sleeves. The arm is cold, cyanotic, and moist, but it is not swollen. Pulses at the wrist are normal, and neurologic function of the three major nerves is intact. Which of the following is most appropriate to provide diagnostic confirmation of the nature of the problem and eventual therapy? A. Angiogram and subclavian vein bypass B. Cervical spine x-rays and cervical rib resection C. Doppler studies and arterial reconstruction D. Doppler studies and fasciotomy E. Sympathetic block and surgical sympathectomy Explanation: The correct answer is E. The description is that of causalgia, also known as reflex sympathetic dystrophy. If sympathetic block relieves the symptoms, permanent cure will be obtained with surgical sympathectomy. Venous occlusion (choice A) would produce swelling but not this kind of pain. Cervical ribs (choice B) can produce neurologic and vascular symptoms in the arm, but they are related to activity and position and do not have the nature described here. Normal pulses make arterial insufficiency (choice C) unlikely. Furthermore, there is no description of intermittent claudication. Compartment syndrome (choice D) might have happened at the time of injury, but if that were the case, it would be too late to do a fasciotomy. A 79-year-old man with atrial fibrillation develops an acute abdomen. When seen 2 days after the onset of the abdominal pain, he has a silent abdomen, with diffuse tenderness and mild rebound. There is a trace of blood on the rectal examination. He also has acidosis and looks quite sick. X-ray films show distended small bowel and distended right colon, up to the middle of the transverse colon. Which of the following is the most likely diagnosis? A. Acute pancreatitis B. Mesenteric ischemia C. Midgut volvulus D. Perforated viscus E. Primary peritonitis Explanation: The correct answer is B. The setting of an old patient with atrial fibrillation (or a recent myocardial infarction) who develops an acute abdomen, strongly suggests embolus to the mesenteric vessels. The combination of abdominal pain and a trace of blood in the lumen is also typical, as is the x-ray film outlining the territory supplied by the superior mesenteric. He probably has a dead bowel by now, as evidenced by his acidosis and severe illness. Any one of the other options could exist, but none are the most likely. Acute pancreatitis (choice A) would be expected in an alcoholic or a patient with biliary tract disease. There would have been no blood in the lumen. Midgut volvulus (choice C) would be far more likely to happen to an infant with malrotation. A perforated viscus (choice D) is indeed possible, but the x-ray films would have shown free air rather than distended bowel. Primary peritonitis (choice E) would have been a consideration in a patient with preexisting ascites. During a hunting trip, a young man is bitten by a coyote. The animal is captured and brought to the authorities alive. Which of the following is the most important criterion to determine the patient's need for rabies prophylaxis? A. The patient's history of previous immunizations B. The patient's clinical course over the next few weeks C. Observing the animal's behavior over the next few days D. Killing the animal and examining the brain E. The events that took place have already established the need to proceed with rabies immunization Explanation: The correct answer is D. Examination of the animal's brain for signs of rabies will determine whether the painful and risky process of rabies passive and active immunization is required. History of previous immunizations (choice A) is used to determine what to do for tetanus prophylaxis, but it has no application for rabies, because virtually no one has ever received such immunization in the past. Waiting for signs of rabies to appear in the patient (choice B) would be a death sentence. We can prevent rabies, but once established we cannot cure it. Observation of the animal's behavior (choice C) is applicable when dealing with provoked bites by domestic pets. The behavior of a wild animal gives no clues to the presence or absence of rabies. If the animal had escaped, choice E would have been correct. The unrestrained front-seat passenger in a car that crashed at high speed arrives at the emergency department with signs of moderate respiratory distress. Physical examination shows no breath sounds at all on the left hemithorax. Percussion is unremarkable, and his vital signs are normal. A chest x-ray film shows a collapsed left lung and multiple air-fluid levels filling the left pleural cavity. A nasogastric tube that had been placed prior to taking the film shows the tube reaching the upper abdomen and then curling up into the left chest. Which of the following is the most likely diagnosis? A. Blow out of pulmonary blebs B. Esophageal rupture or perforation C. Left diaphragmatic rupture D. Left hemopneumothorax E. Major injury to the tracheobronchial tree Explanation: The correct answer is C. The left diaphragm can blow out with blunt injuries, allowing the bowel to move up into the chest. The multiple air-fluid levels suggest that bowel is indeed there, and the trajectory of the nasogastric tube confirms that the abdominal viscera (including the stomach) have been sucked up into the thoracic cavity. Pulmonary blebs (choice A) produce a pneumothorax when they rupture. The esophagus (choice B) virtually never ruptures with blunt abdominal trauma. You need a penetrating injury, or better yet an endoscopy, to perforate it. When that happens, the outcome is mediastinitis. A hemopneumothorax (choice D) can indeed happen in thoracic injuries, but the x-ray films would show one single large air-fluid level, and the nasogastric tube would be in the stomach, without curling up into the chest. The tracheobronchial tree (choice E) can indeed break as a consequence of deceleration injuries, but the outcome would be a pneumothorax and air in the mediastinum and the subcutaneous tissues. A car is involved in a head-on collision. The driver, who is sober and wearing his seat belt, explains that he clearly saw his drunk, unrestrained front seat passenger hit the windshield with his face and the dashboard with his knees. Examination of the passenger indeed shows multiple facial lacerations, but because of his intoxication he cannot explain where else he might be hurting. He is neurologically intact, and his cervical spine x-ray films are normal. Additional injury, representing a potential orthopedic emergency, is not obvious but is suspected. Therefore, an x-ray film of which of the following areas should most likely be obtained? A. Both patellas B. Both hips C. The jaw D. The lumbar spine E. The skull Explanation: The correct answer is B. When hitting the knees against the dashboard, the femurs can be driven backward and out of the acetabulum, resulting in posterior dislocation of the hips. Because of the tenuous blood supply of the femoral heads, such injury must be promptly recognized and treated. Both patellas (choice A) and the jaw (choice C) could indeed be fractured, but such fractures would be easily recognized clinically. If they were not identified until the next day, no damage would be incurred. The lumbar spine (choice D) should always be thought of when someone falls from a height and lands on his feet, but it is not a likely hidden injury in this setting. Skull x-ray films (choice E) have gone out of favor as a way to assess head injury. The main issue in head injuries is intracranial bleeding, and the study to show it is the CT scan. A 14-year-old boy slides down a banister and crashes into a large ornamental knob at its base, thereby injuring his scrotal contents. He presents in the emergency department with acute testicular pain and a scrotal hematoma the size of a grapefruit. He is able to void normally, and his urine does not contain blood. A rectal examination is unremarkable. Findings from which of the following tests will most likely determine further therapy? A. Aspiration of scrotal contents B. Retrograde cystogram C. Retrograde urethrogram D. Scrotal sonogram E. Scrotal surgical exploration Explanation: The correct answer is D. The clinical findings do not suggest urethral injury, but testicular fracture is a potential injury that would require surgical intervention. Sonogram would be diagnostic. Aspiration (choice A) is not a good idea. We already know that blood is present, and putting needles into it would invite bacterial contamination. If the testicle is intact, the hematoma will resolve spontaneously. Neither the bladder (choice B) nor the urethra (choice C) need to be checked when the urine has no blood, the patient can void normally, and the rectal examination is unremarkable. Surgical exploration (choice E) is not indicated unless a diagnosis of testicular rupture has been made. A 25-year-old man is stabbed once in the right chest. The entrance wound is on the midaxillary line, at the level of the fifth intercostal space. He arrives at the emergency department moderately short of breath, but he is fully awake and alert, is talking with a normal tone of voice, and has no distended veins visible in his neck or forehead. His blood pressure is 130/75 mm Hg, and his pulse is 82/min. Physical examination of the chest shows the wound, which is not visibly "sucking air," and demonstrates no breath sounds at all on the right side, which is tympanitic to percussion. There is no evidence of mediastinal displacement. Which of the following would be the most appropriate next step in management? A. Cover the wound with a regular dressing and get a chest x-ray B. Cover the wound with Vaseline gauze, taped on three sides C. Endotracheal intubation D. Insert a chest tube at the right pleural base E. Insert an 18-gauge needle into the right pleural space at the second intercostal space Explanation: The correct answer is A. The clinical picture is that of a pneumothorax, but there is no life-threatening situation that would prevent obtaining a radiologic diagnosis of the exact nature and extent of the problem. Then the appropriate therapy can be instituted. Covering the wound with Vaseline gauze (choice B) is the standard advice for sucking chest wounds to prevent further inflow of air into the pleural space. This is not happening here. Endotracheal intubation (choice C) is not needed if he has a good airway. A person who is fully awake and has a normal tone of voice has a normal airway. A chest tube (choice D) should not be inserted blindly, not knowing yet what is going on. He may very well need a tube at the base if the x-ray shows a hemothorax, but we might prefer to put it at the top if all he has is air. Insertion of a needle (choice E) is the correct answer when there is a life-threatening tension pneumothorax. In that case, he would have been in shock, with distended veins and mediastinal displacement. The unrestrained front-seat passenger in a car that crashes sustains closed comminuted fractures of both femoral shafts. Shortly after admission, he develops a blood pressure of 80/50 mm Hg, a pulse rate of 110/min, and a venous pressure of zero. He becomes pale, cold, and clammy, but the rest of his physical examination and x-ray films of the chest and pelvis are unremarkable. A sonogram of the abdomen done in the emergency department is likewise negative. Which of the following is the most likely reason for the low blood pressure? A. Blood loss at the fracture sites B. Fat embolism C. Neurogenic shock from pain D. Unrecognized intracranial bleeding E. Unrecognized pericardial tamponade Explanation: The correct answer is A. Comminuted fractures of the femurs are known to be one of the few places in the body where enough occult blood loss may occur to lead to hypovolemic shock. Fat embolism (choice B) is also associated with long bone fractures, but the manifestations are those of respiratory failure, rather than hypovolemic shock. Neurogenic shock (choice C) would rarely occur from pain alone, being more common as a sequela of high spinal cord transection. When it happens, the patient is hypotensive but looks warm and flushed rather than cold and pale. Intracranial bleeding (choice D) can lead to neurologic symptoms, but not to hypovolemic shock. There is not enough room within the head to accumulate the sizable blood loss required to go into shock. Pericardial tamponade (choice E) would produce high central venous pressure. A 49-year-old woman has a firm, 2-cm mass in the right breast that has been present for 3 months. Mammogram has been read as "cannot rule out cancer," but it cannot diagnose cancer either. A fine-needle aspiration of the mass (FNA) and cytology do not identify any malignant cells. Which of the following is the most appropriate next step in management? A. Reassurance and reappointment in a year B. Repeat mammogram and FNA in 1 month C. Core or incisional biopsies D. Lumpectomy and axillary dissection E. Modified radical mastectomy Explanation: The correct answer is C. Negative findings do not have the same diagnostic value that positive findings have. If this had been a 19-year-old woman suspected of having a fibroadenoma, one would have been satisfied with negative imaging studies (in that age, a sonogram) or the negative FNA. But, at age 49, the risk of cancer is much higher. Given negative findings in the least invasive studies, one would feel compelled to move to more aggressive ways to obtain better tissue sampling. Obviously, reassurance (choice A) is not justified yet, and waiting a whole year with what may be a cancer would be malpractice. Repeating the same studies in a month (choice B) leaves you with the quandary of what to do if they are negative again. No, you need more tissue for the pathologist right now. Lumpectomy and axillary dissection (choice D) is too much to do before the diagnosis has been established. Lumpectomy alone might have been okay. An excisional biopsy could indeed be justified under the circumstances, and a lumpectomy is not much more than a big excisional biopsy. But, messing with the axilla should not happen before we know it is cancer. Mastectomy (choice E) is even less acceptable. Patients are grateful when a cancer is ruled out by procedures that they do not perceive as mutilating. But, when surgery leaves them deformed, the "good news" that there was no cancer may lead them to call their lawyer. A 25-year-old man is stabbed in the right chest. He comes in fully awake and alert, and, in a normal tone of voice, he states that he feels short of breath. His vital signs are normal and stable. On physical examination, he has no breath sounds at the right base, and only faint breath sounds at the apex. He is dull to percussion over the right base. A chest x-ray film confirms that he has a hemothorax on that side. Which of the following is the most appropriate next step in management? A. Oxygen by mask, analgesics, and no specific intervention B. Intubation and use of a respirator C. Insertion of a chest tube in the right second intercostal space D. Insertion of a chest tube at the right base E. Exploratory thoracotomy Explanation: The correct answer is D. Although he is hemodynamically stable, and thus presumably not "bleeding to death," contaminated blood should not be left in the pleural space, where it could lead to the development of an empyema. A chest tube placed at the base should evacuate it. In doing so, we will also learn whether the amount of blood recovered justifies a more aggressive step to stop the bleeding. No specific intervention (choice A) is incorrect because that contaminated blood needs to come out. Intubation and respirator (choice B) are not needed. A patient who is awake and alert and speaking in a normal tone of voice has a good airway. He does not need intubation. Neither does he need a machine to breathe for him, when he is doing it spontaneously. A chest tube high in the pleural space (choice C) is the correct prescription for a pneumothorax, but not for a hemothorax. Air goes to the top, and blood goes to the bottom. To retrieve the blood, the tube has to be at the bottom. Thoracotomy (choice E) is seldom needed for a hemothorax. Bleeding is usually from the lung, and it stops by itself. When a systemic vessel is injured (typically an intercostal), we find a lot of blood when the tube is placed (more than 1000 or 1500 mL), or a substantial amount drains out in the ensuing few hours (more than 600 mL in 6 hours). Only in those cases is a thoracotomy indicated. A blond, blue-eyed, 69-year-old sailor has a non-healing, indolent, 1.5-cm ulcer on the lower lip, arising from the vermilion border. The ulcer has been present and growing for the past 8 months. He is a pipe smoker, but has no history of alcohol or drug abuse. Physical examination shows "weather-beaten" facial skin, but no other ulcers. There are no enlarged lymph nodes in his neck. Which of the following is the most likely diagnosis? A. Adenocarcinoma B. Basal cell carcinoma C. Benign ulceration due to chronic trauma D. Invasive malignant melanoma E. Squamous cell carcinoma Explanation: The correct answer is E. The location and history are classic for squamous cell carcinoma of the lower lip. The absence of metastatic nodes does not invalidate the diagnosis, as most cancers in this location do not metastasize until quite late. Adenocarcinoma (choice A) would be very rare in the lower lip. Basal cell carcinoma (choice B) favors the upper part of the face, above a horizontal line drawn across the mouth. Benign ulceration (choice C) is always a possibility, but it would be a terrible mistake to make such assumption. As pointed out before, this vignette is a "textbook case" for squamous cell carcinoma. Melanoma (choice D) is again very rare in this location. A history of a pigmented lesion that underwent changes in color, appearance, or diameter would have been suggestive. A 71-year-old West Texas farmer of Irish ancestry has a nonhealing, indolent, punched out, clean-looking 2-cm ulcer over the left temple. The ulcer has been slowly growing over the past 3 years. There are no enlarged lymph nodes in the head and neck. Which of the following would best dictate proper management? A. Full thickness biopsy of the center of the lesion B. Full thickness biopsy of the edge of the lesion C. Pathologic studies after the entire lesion is resected with a margin of 1 cm of normal skin all around D. Response to a trial of radiation therapy E. Scrapings and culture of the ulcer base Explanation: The correct answer is B. The history (a fair skinned person who is out in the sun all day) suggests a skin cancer, and the location (the upper part of the face) favors a basal cell cancer but does not exclude a squamous cell carcinoma, or even a melanoma. Thus, diagnosis is needed before proper therapy is instituted. The edge of the lesion offers the best information for the pathologist. A biopsy of the center of the lesion (choice A) deprives the pathologist of all the clues that are found at the interface between the tumor and the normal skin, and in large lesions it runs the risk of sampling necrotic tumor that has outgrown its blood supply. A wide excision before pathologic diagnosis (choice C) risks doing too much (a basal cell cancer needs only 1 or 2 mm of margins) or too little (a melanoma should have at least 2 cm). Radiation therapy (choice D) is a viable therapeutic choice for squamous cell carcinoma, but not before a diagnosis has been established. Here, we are expecting a basal cell carcinoma, thus this course of action would be even less appropriate. Scrapings and cultures (choice E) assume an infectious process, ignoring the strong clinical suspicion of a tumor in this case. A 44-year-old woman is recovering from a mild episode of acute ascending cholangitis secondary to choledocholithiasis. When seen initially, she had a spiking fever, leukocytosis, and a very high alkaline phosphatase; however, all these findings subsided rapidly after she was placed on IV antibiotics. A sonogram of the right upper quadrant on the day of admission showed the presence of gallstones in the gallbladder, but the diameter of the biliary ducts was normal. It was assumed that she had passed a common duct stone, and plans to do an endoscopic retrograde cholangiopancreatogram (ERCP) were canceled. While awaiting elective cholecystectomy, she again developed a fever and leukocytosis, and her liver function tests showed minimal elevation of her bilirubin (to 2.5 mg/dL) and alkaline phosphatase (to 115 U/L). A repeat sonogram shows no changes in her biliary ducts, but now there is a 6-cm abscess in the right lobe of the liver. Which of the following is the most appropriate treatment for this new development? A. Metronidazole B. Long-term IV antibiotics C. ERCP and biliary drainage D. Percutaneous drainage of the liver abscess E. Open surgical resection of the right lobe of the liver Explanation: The correct answer is D. Liver abscess complicating biliary tract disease is described as "pyogenic" abscess (to contrast it with amebic abscess), and it requires drainage like any abscess anywhere else in the body. The percutaneous route is favored. Metronidazole (choice A) is the therapy of choice for amebic abscesses of the liver, and that condition represents the only exception to the rule that all abscesses have to be drained. However, this is not an amebic abscess. Amebic abscesses are seen in men (4 to 1 ratio compared with women) who come from Mexico, where the disease is very common. Long-term antibiotics (choice B) will not reach and sterilize an abscess. Abscesses have to be drained. Endoscopic retrograde cholangiopancreatogram (ERCP) (choice C) is often urgently needed to treat acute ascending cholangitis, but it will not do anything for a liver abscess. Resection (choice E) is not needed for a liver abscess. Drainage is enough. A pedestrian is hit by a car. The paramedics report that he was unconscious at the site, and he arrives at the emergency department in coma, strapped to a head board with sandbags on either side of his head. Initial survey shows stable vital signs, and his pupils are of equal size and reactive to light. He is rapidly intubated by the nasotracheal route over a flexible bronchoscope and then sent for CT scans of the head. As he is being positioned on the table, it is noted that there is a sizable hematoma behind his right ear and that clear fluid is dripping from the ear canal. Which of the following is most advisable, considering this new finding? A. Extend the CT scan to include his neck B. Do an MRI instead of a CT scan C. Start antibiotics D. Inject high-dose corticosteroids E. Plan an emergency craniotomy Explanation: The correct answer is A. The clinical findings are indicative of a fracture of the base of the skull, and thus he has sustained very significant trauma to the head. The integrity of the cervical spine has to be ascertained, and the CT that he is already going to have can be extended to include that area. MRI (choice B) has no role in the acute trauma situation. If we were looking for a brain tumor, at leisure, an MRI would indeed be better than a CT-but not in this setting. Antibiotics (choice C) have proven to be of no value in base of the skull fractures. Corticosteroids (choice D) are being used in patients with spinal cord injury, but we have not yet diagnosed the presence of such an injury. Emergency craniotomy (choice E) is not needed to deal with a basilar skull fracture. He would need one if his CT scan showed an intracranial hematoma displacing the midline structures. He might need one later if the leak of CSF persists, but he does not need one now. A 23-year-old man known to have neurofibromatosis, type 1 (von Recklinghausen's disease), presents with a left lower quadrant abdominal mass and signs of neurologic deficits in his left leg. In the ensuing workup, it is determined that he has higher than normal values of catabolites of epinephrine and norepinephrine in a 24-hour urinary collection. He is currently normotensive. Before invasive steps are taken to biopsy and eventually remove his left lower quadrant abdominal mass, which of the following is the most appropriate next step in management? A. CT scan of the head looking for meningiomas B. MRI of his adrenal glands C. MRI of the acoustic nerves D. Radionuclide scans from the neck to the pelvis looking for extra-adrenal pheochromocytomas E. Radiation therapy to the left lower quadrant abdominal mass Explanation: The correct answer is B. The concern is that even though he is now normotensive, invasive steps might trigger a hypertensive crisis from the previously undiagnosed pheochromocytoma that he probably has. The presence of catabolites from epinephrine indicates that the tumor is in the adrenal glands, and not at an extra-adrenal site. Thus, the diagnosis of the pheochromocytoma can best be confirmed by MRI of the adrenals. Meningiomas (choice A) and acoustic nerve tumors (choice C) occur in type 2 neurofibromatosis, not in type 1. Looking for pheochromocytomas outside of the adrenal glands (choice D) would have been a good idea if only elevated catabolites of norepinephrine had been detected. The presence of high levels of epinephrine catabolites implicates the adrenal glands. Radiation therapy (choice E) is a bad idea. Benign neurofibromas can be stimulated by radiation to undergo malignant transformation. A middle-aged homeless man is brought to the emergency department because of very severe pain in his forearm. He had passed out after drinking a bottle of cheap wine, and then slept on a park bench for an indeterminate time, probably more than 12 hours. Shortly after he woke up and began to walk, the pain began. There are no signs of trauma, but the muscles in his forearm are very firm and tender to palpation, and passive motion of his fingers and wrist elicits excruciating pain. Pulses at the wrist are normal. Which of the following is the most appropriate next step in management? A. Analgesics and observation B. Immobilization in a sling C. Immobilization in a plaster cast D. Emergency embolectomy E. Emergency fasciotomy Explanation: The correct answer is E. The presentation is classic for compartment syndrome, triggered by prolonged ischemia followed by reperfusion (the arm pressed against the park bench until he woke up and changed position), and located in one of the two most common sites (forearm and lower leg). He has the most reliable physical finding (pain on passive extension), and the diagnosis is not ruled out by normal pulses. Only a fasciotomy will solve his problem. Analgesics and observation (choice A) will result in permanent damage to the compartment muscles. Immobilization, by sling (choice B) or cast (choice C), will allow the high pressure within the compartment to continue to destroy the muscles. Embolectomy (choice D) assumes an arterial occlusion, which his normal pulses rule out. A 54-year-old obese man gives a history of burning retrosternal pain and heartburn that is brought about by bending over, wearing a tight belt, or lying flat in bed at night. He gets symptomatic relief from overthe-counter antiacids or H2 blockers, but has never been formally studied or treated. The problem has been present for many years and seems to be progressing. Which of the following is the most appropriate next step in management? A. Barium swallow B. Cardiac enzymes and ECG C. Proton pump inhibitors D. Endoscopy and biopsies E. Laparoscopic Nissen fundoplication Explanation: The correct answer is D. The clinical picture is fairly convincing for long-standing gastroesophageal reflux. The main concern is the degree of peptic esophagitis that he may have developed, and the possibility of Barrett's esophagus and premalignant changes. Endoscopy and biopsies will provide the answer. Barium swallow (choice A) would provide anatomic evidence of hiatal hernia and evidence of reflux, but would not tell us whether Barrett's esophagus has developed. Cardiac enzymes and ECG (choice B) would be part of the work-up (along with pH monitoring) if we were uncertain as to the genesis of ill-defined low retrosternal and upper epigastric pain. This man gives a classic presentation for reflux. Proton pump inhibitors (choice C) might likewise be indicated for this man, but not until we know the severity and potential premalignant stage of his disease. Nissen fundoplication (choice E) may some day be needed here, but one would not jump to a surgical solution based only on a clinical presentation. A 72-year-old man comes in complaining of persistent and nagging low back pain that he has had for several weeks. The pain seems to be increasing in intensity, is worse at night, is unrelieved by rest or positional changes, and is not exacerbated by coughing, sneezing, or straining to have a bowel movement. He is a chronic smoker, and for the past 3 months has had persistent cough with occasional bloody streaked sputum, as well as a 20-pound weight loss. On physical examination, he is distinctly tender to palpation at a particular spot over his lower thoracic spine. Which of the following is the most likely diagnosis? A. Ankylosing spondylitis B. Herniated disk C. Metastatic tumor to the thoracic spine D. Multiple myeloma E. Primary malignant bone tumor Explanation: The correct answer is C. The age, nature of the pain, physical findings, and associated symptoms are all highly suggestive of metastatic tumor, and the source is probably the lung. Ankylosing spondylitis (choice A) happens to younger patients (in their early 30s) who have pain and stiffness in the mornings, and relief as they become active during the day. Herniated disc (choice B) can virtually be excluded by the fact that the pain is not exacerbated by coughing, sneezing, or straining. Multiple myeloma (choice D) is also a disease of old men, but they get anemia and multiple lytic lesions throughout the skeleton. Primary malignant bone tumors (choice E) occur in much younger people, and the extremities are a more likely location. A 24-year-old woman is admitted to the hospital for a broken femur. The patient was in a motor vehicle accident 20 hours ago and was brought to the hospital by EMS. On the scene, she was found belted in her car in the drivers seat, and her only documented injury was the leg fracture. She had no loss of consciousness or altered mental status. On arrival to the hospital, radiographs confirmed a fracture of her femur. She was stabilized over night and scheduled for surgery the next day. Which of the following is the major surgical risk for this patient? A. Air embolism B. Cerebrovascular accident C. Fat embolism D. Osteomyelitis E. Permanent disability Explanation: The correct answer is C. If a transesophageal echo probe is placed in every patient undergoing femoral reaming for fracture repair, the incidence of fat and particle debris in the right atrium approaches 70%. In fact, a major risk of lower extremity orthopedic procedures is pulmonary embolism due to fat or clots. The intramedullary pressures generated during the repair are greater than 500 psi and are enough to cause venous extrusion of fat and other particulate matter into the circulation. Air embolism (choice A) is common with neurosurgical procedures but is not often seen with orthopedic procedures of the lower extremity. Although cerebrovascular accident (choice B) can occur in the absence of a patent foramen ovale, it is rare. Osteomyelitis (choice D) is a feared complication of orthopedic surgery, and precautions such as sterile preparations and antibiotics are taken to guard against it. Because of this, the complication of pulmonary embolism due to fat is much greater than that of bone infection. Permanent disability (choice E), although a vague term, would rarely be the result of a lower extremity fracture repair. A 27-year-old immigrant from El Salvador has a 14 × 12 × 9 cm mass in her left breast. It has been present for 7 years and has slowly grown to its present size. The mass is firm, nontender, rubbery, and completely movable, and it is not attached to the overlying skin or the chest wall. There are no palpable axillary nodes or skin ulceration. Which of the following is the most likely diagnosis? A. Breast cancer B. Chronic cystic mastitis C. Cystosarcoma phyllodes D. Intraductal papilloma E. Mammary dysplasia Explanation: The correct answer is C. Cystosarcoma phyllodes occurs in young women, grows to huge size over many years, and yet spares the skin, the nodes, and the underlying chest wall. There is no particular connection with Central America, but often these are seen in immigrants of limited financial circumstances, who have had no access to medical care in their own countries. Breast cancer (choice A) this big and for these many years, would have ulcerated the skin, would be fixed to the chest wall, and would have produced massive axillary metastasis. Chronic cystic mastitis (choice B), also known as mammary dysplasia (choice E), is seen in women of reproductive age, who complain of tender and lumpy breasts related to the menstrual cycle. Large cysts can develop in this disease, but not to the huge size described in the vignette. Intraductal papilloma (choice D) is the most common source of bleeding from the nipple. These tumors are tiny, just a few millimeters in diameter. A 54-year-old man, who 5 years ago underwent a laparotomy for a gunshot wound to the abdomen, is admitted to the hospital because of protracted vomiting and progressive abdominal distention. The symptoms began 5 days earlier, and since then he has not had a bowel movement or passed any gas. At the time of hospitalization, he has hyperactive bowel sounds and some abdominal discomfort, but does not have an acute abdomen. His abdominal x-ray films show dilated loops of small bowel, multiple air-fluid levels, and no free air under the diaphragms. He is placed on nasogastric suction and IV fluids. After 6 hours, he develops fever, leukocytosis, abdominal tenderness, and rebound tenderness, and his abdomen is silent. Which of the following is the most appropriate next step in management? A. Add antibiotics B. Barium tag and serial abdominal x-ray films C. CT scan of the abdomen D. Upper gastrointestinal endoscopy and introduction of a long intestinal tube E. Emergency exploratory laparotomy Explanation: The correct answer is E. He came in with mechanical intestinal obstruction due to adhesions, and has now developed signs of bowel strangulation. If the strangulated loop is still viable, it has to be freed immediately. If it is necrotic, it has to be resected with equal urgency to prevent continued peritoneal soiling. Antibiotics (choice A) will not provide viability to a compromised loop of bowel, nor prevent peritonitis if the loop is dead. Barium tag (choice B) is what we do in the postoperative period after abdominal surgery when we cannot decide whether a sluggish bowel has paralytic ileus or early mechanical obstruction. This is not the situation here. CT scan (choice C) is our universal answer when we do not know what is happening inside the belly. Here we do. Had he shown up with obstruction, and no reasonable etiology for it (no prior surgery, no hernias), we might have done a CT. Endoscopy and a long tube (choice D) will not take care of dead or dying bowel. A 59-year-old man is referred for evaluation because he has been fainting at his job, where he operates heavy machinery. He is pale and gaunt, but otherwise his physical examination is remarkable only for 4+ occult blood in the stool. Laboratory studies show a hemoglobin of 5 gm/dL with microcytosis, as well as decreased levels of serum iron and increased iron binding capacity. Which of the following will most likely establish the diagnosis? A. Upper gastrointestinal series (swallowed barium studies) B. Colonoscopy C. Flexible sigmoidoscopy to 45 cm D. Upper gastrointestinal endoscopy E. Visceral angiogram Explanation: The correct answer is B. Iron deficiency anemia in the adult is always due to chronic blood loss, and the source is obvious in this vignette: the gastrointestinal tract. In turn, the most likely site, in the absence of other symptoms, is a cancer of the right side of the colon, which is best seen by colonoscopy. Upper gastrointestinal series (choice A) would not be likely to reveal the source of this man's anemia, since the cecum or ascending colon is the number one target. Flexible sigmoidoscopy (choice C) would not reach the likely site of the cancer. If the cancer were located in the left colon, he would likely have visible blood in his stools and a change in bowel habits. Upper gastrointestinal endoscopy (choice D) is the first test when someone vomits blood. It often will also reveal the source of occult blood loss (peptic ulcer disease or aspirin-related gastritis) when the colon is found to be normal. In this case, however, the cecum or ascending colon is the number one target. As for visceral angiogram (choice E), it would be great at the time of massive gastrointestinal bleeding (more than 2 mL/min), but in this example it would be a very expensive, invasive, and roundabout way to demonstrate the presence of a tumor (by tumor blush). A young mother is at the pediatrician's office for a routine well-baby visit for her 18-month-old son. It is immediately noticed that one of the baby's pupils is white, while the other one is black. When asked about it, the mother relates that she saw that curious situation for the first time 1 week ago, but since the baby was otherwise asymptomatic, she did not think it merited special attention. Which of the following is the most appropriate course of action? A. Do nothing, this is a normal anatomic variant B. Inquire if the father is an albino, and do appropriate genetic counseling C. Seek an ophthalmologic consultation for suspected congenital cataract D. Seek an emergency ophthalmologic consultation for possible retinoblastoma E. Treat the child with antibacterial eye drops and re-check in 2 weeks Explanation: The correct answer is D. A newly developed white pupil in a child raises the possibility of retinoblastoma. This tumor is so deadly that immediate diagnosis and treatment are imperative. Ignoring the finding (choice A) could prove to be lethal, and the same can be said for any delays caused by pursuing bizarre considerations, such as looking for albinos in the family (choice B) or treating for an eye infection that is not there (choice E). It could be argued that if an ophthalmologic consultation is obtained, even if it is for a wrong diagnosis (choice C), the true nature of the problem will eventually be recognized. But an appointment to check for cataracts (which would have been present since birth) will not be made with the same urgency that the situation requires.