NORMAL:
Slide 2: Note the crescent shape
opening of a normal appendix
seen in the base of the cecum.
The slitlike opening into the
appendix is seen below the
converging tenia.
Slide 3: This slide demonstrates
views of the folds in the normal
ascending colon. The folds are
slightly thicker than in the
transverse colon and the
triangular configuration is
evident.
Slide 4: This view of
the normal colon
demonstrates the
delicate vascular
pattern of the colonic
mucosa.
Slide 5: These views
demonstrate the normal
transverse colon with its
typical configuration
caused by three teniae.
Notice the typical triangular
appearance with finer or
thinner folds.
Slide 6: After passing the splenic
flexure, the descending colon is
more circular and tubular. This
slide demonstrates normal sigmoid
colon.
Slide 7: The normal rectum above the
anal canal is seen from the inside with a
colonscope retroflexed. This enable the
endoscopist to see lesions just inside the
anal canal which can be easily missed
otherwise.
DISEASED:
Slide 8: Polypoid lesions are
the most common pathology
found during colonoscopy.
The most common types are
hyperplastic, tubular, and
villous. This slide shows a
hyperplastic polyp on top of a
mucosal fold. They are
usually single, but up to 10%
of patients may have as many
as five or ten in a single
segment of bowel. They are
entirely benign when
biopsied.
Slide 9: Shown here is a small,
sessile, tubular adenoma with
normal overlying mucosa.
Tubular adenomas are much
less likely to develop cancer
than are villous adenomas.
Most adenomas under 2 cm can
be removed endoscopically.
Slide 10: This rectal villous
adenoma shows superficial
central ulceration suggestive of
malignancy. Of all villous
adenomas, one third are benign, one third have
carcinoma in situ, and one third will demonstrate
invasive carcinoma. In addition to the effect of
histologic type on the development of cancer, the
size of a polyp is also important. Polyps greater than
2 cm are much more likely to become malignant.
Surgery for polyps is indicated in those too larger to
remove safely through the colonscope and in those
showing carcinoma histologically.
Slide 11: Colonscopic polypectomy
is demonstrated in this slide. The
snare wire is maneuvered around
the polyp and the snare is
tightened. The diathermy current
coagulates the base of the polyp
and it is removed for histologic
examination.
Slide 12:
Adenocarcinoma
of the colon may
appear as an
ulcerated mass, an
annular mass, or
as a polypoid,
nonulcerated,
exophytic mass as
shown here. This
tumor is
obstructing the
transverse colon.
Directed biopsy of the cancer is shown on the right. Tumors in the cecum are more often
ulcerated and therefore present with anemia or occult blood loss. Left sided lesions are
more often of the annular, "napkin ring" type and thus most often present with
obstruction.
Slide 13: Colonoscopy is an
established procedure for evaluating
patients with inflammatory bowel
disease. This slide shows examples of
ulceration in active ulcerative colitis.
Background mucosa shows marked
erythema and friability. The colitis
may extend throughout the colon or
involve only part of it. Chracteristically
the rectal mucosa is affected.
Granularity is commonly seen as are
superficial or deep ulcerations which
may by linear, serpiginous, or ovoid.
Slide 14: This slide shows the
appearance of longstanding ulcerative
colitis with tubularization of the colon.
Plaques of exudate and punctiform
petechial hemorrhages are also
apparent.
Slide 15: Ulceration is a dominant
abnormality in Crohn's disease. This
slide shows multiple larger, deep,
excavated ulcers with distinct margins
in a patient with Crohn's disease. The
common patterns for Crohn's include:
1) involvement of the terminal ileum
only (50%), 2) small bowel and colon
involvement in a continuous or skip
pattern (33%), and 3) jejuno-ileitis
(12%).
Slide 16: This slide shows
diverticulosis of the colon. Although
the sigmoid is the most common site,
these outpouchings may occur
throughout the colon and are seen as
2 to 5 mm openings. Obstruction of
these openings may result in
diverticulitis while ulceration at the
dome of a diverticulum may erode
into a vessel and result in diverticular
bleeding.
Slide 17: This
slide
demonstrates the
usual
appearance of
angiodysplasia
in the mucosa of
the colon. A
larger
angiodysplasia
and multiple
small angiodysplasias are interconnected in these views. These lesions can be located
anywhere in the GI tract but are typically in the right colon and cecum. This entity, along
with diverticulosis, represents the most common cause for massive lower GI bleeding in
the elderly. Definitive treatment involves resection of the portion of colon bearing the
angiodysplasia.
Slide 18: This patient developed
Clostridium difficile overgrowth
leading to severe pseudomembranous
colitis after clindamycin therapy.
Raised, strongly adherent, yellow
plaques are characteristic features.
Almost every antibiotic has been
implicated in this disease. The most
common culprit currently is the
cephalosporin group of antibiotics. The
treatment is Vancomycin or Flagyl.
Slide 19: This slide shows Amebiasis of
the rectosigmoid junction. Small
superficial ulcerations are covered with
white exudate and surrounded by an
erythematous rim. Amebiasis caused by
Entamoeba histolytica has a predilection
for the cecal and rectosigmoid area.
Treatment is oral Flagyl. Other causes of
infections colitis include
Camphylobacter, Yersinia, Salmonella
and Shigella.
Rads Teaching Set
Patient A: The AP double
contrast view of the colon
demonstrates a multilobulated
polypoid mass in the lateral
aspect of the cecum. The
pathologic diagnosis was villous
adenoma with malignant
change.
Patient B: This AP double-contrast view of the
colon differs from the previous patient. This
carcinoma of the cecum would be described as a
fungating, polypoid mass which is completely
filling and obliterating the cecum. This type of
lesion may present as an intussusception or may
cause obstruction at the ileocecal valve, although in this particular patient, there is no
direct evidence of small bowel obstruction at the level of the valve.
Patient C: A right decubitus view of this double-contrast
colon study demonstrates a redundant colon which is of
normal color with the exception of a focal lesion seen in
the distal descending colon, probably at the sigmoid-
descending colonic junction. The lesion is considered short
in axial length (4-5 cm), is angular and constricting in
nature with a short central stenotic lumen. The abrupt
demarcation between the lesion and normal colon, both
proximally and distally, is characteristic of a very
desmoplastic adenocarcinoma.
Patient D: This 27 year-old male demonstrates
classic findings of familial polyposis coli. He has a
twin brother with the same condition. A left
decubitus view of the air contrast colon
examination demonstrates multiple diffuse surface
nodules representing polyps. These are very
characteristic- their size is fairly uniform, ranging
from an average of 2-5 cm. The uncountable
number of polyps diffusely present from the cecum
through the rectum is characteristic of the disease
process. These polyps may be distinguished from a
diffuse ulcerative process by the fact that there are
no abnormal focal collections of barium as would
be seen in small ulcerations. If one looks at the
profile or contour edge of the colon, there are no
projections out beyond the expected lumen. The
lesions project inward towards the lumen, a
characteristic of a polypoid lesion on the mucosa.
Patient E: This film is a slightly left oblique air
contrast view of the colon. There are a few
incidental diverticula seen in the proximal
ascending colon, as well as in the distal descending.
In the mid-sigmoid colon, there is a typical large
pedunculated polyp. The stalk is approximately 3
cm in length and the head of the polyp is somewhat
nodular. It measures about 2-3 cm in diameter.
Patient F: There are two films- an AP and a left oblique
to better view the sigmoid colon. This patient has
sigmoid diverticulosis but presents clinically with
evidence of acute
diverticulitis. The
barium enema
findings suggestive
of diverticulitis in
this particular case
are the intense
areas of spasm, giving a more spike-like and corrugated
appearance to the intestinal contour. There are no areas of
focal extravasation of contrast which would be prima facie
evidence for acute diverticulitis. This may be seen either on
barium enema or on CT in about 50% of cases. A barium
enema may be risky in patients with diverticulitis. Free
extravasation of barium may result in barium peritonitis
with its resultant high morbidity and mortality. The CT is
particularly useful in evaluating the extent of pericolonic
inflammation and abscess development.
Patient G: This patient underwent a double-
contrast colon examination which demonstrates
Crohn's colitis. There is evidence of segmental
involvement with areas of disease seen in the
distal sigmoid improving in the mid-sigmoid and
then becoming more severe at the sigmoid-
descending colonic junction and the mid-
descending colon, and relative sparing of the
splenic flexure but with progressively more
involvement in the transverse and hepatic fexture
region. There are areas of contour abnormality
especially in the transverse colon. In this area,
the abnormalities seem to be polypoid or
cobblestone-like with lots of variable-sized
circular and ovoid indentations. The disease may
be asymmetrical in its distribution- worse on one
wall than another with areas of ulcerations as
well as pseudopolyp or cobblestone formation. The overall caliber of the intestine is
narrowed. There are no real discrete ulcerations in this segment. If one looks at the more
barium-filled descending colon, the ulcerations create a serrated margin and the profile
edge is more easily seen. The patient did not have evidence of involvement of the
terminal ileum.
Patient H: This patient has a long history
of ulcerative colitis and on the air
contrast barium enema, one sees an
overall shortening of the colon, both in
length and circumferential diameter. The
colon has a so-called "lead pipe"
appearance. There is complete loss of
haustration in the colon. The mucosal
abnormalities seen in this patient show a
more subtle and smaller defect. There is
a stippled appearance of the barium and
this is referred to as mucosal granularity
which represents areas of nodular
swelling and sub-mucosal edema, as
well as very small but uniformly shaped
ulceration. The areas of abnormality in
ulcerative colitis are seen uniformly in
distribution within the involved
segments as opposed to a more non-
uniform display of the disease in Crohn's
colitis.