Neoplasia Introduction

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					Neoplasia 1:
Introduction
              terminology

• oncology: the study of tumors

• neoplasia: new growth (indicates autonomy
  with a loss of response to growth controls)
          types of neoplasms
• benign: localized and amenable to surgical
  removal; patient usually survives
• malignant: invasive tumor capable of
  destroying structures and spread to distant
  sites (metastasis); may result in early death
  of the patient
      examples of benign tumors

•   fibroma: benign tumor of fibrous tissue
•   lipoma: benign tumor of fat
•   adenoma: benign glandular tumor
•   chondroma: benign cartilaginous tumor
leiomyomas
adenoma
  examples of malignant tumors

• sarcoma (mesenchymal derivation:
  fibrosarcoma, chondrosarcoma)
• carcinoma (epithelial derivation:
  adenocarcinoma, squamous cell carcinoma)
• lymphoma/leukemia
adenocarcinoma
carcinoma
• The terms “benign” and “malignant”
  describe the biologic behavior of a tumor
• the biologic behavior is characterized by
  degree of differentiation of the tumor and
  by the rate of growth (and rate of cell death)
             differentiation
• Well-differentiated tumors contain cells that
  resemble the normal cells of origin
• poorly-differentiated or undifferentiated
  tumors contain cells that do not resemble
  their normal counterparts (ancillary studies
  may be needed to determine the cell of
  origin)
well-differentiated
poorly-differentiated
• Benign tumors are composed of well-
  differentiated cells.
• Malignant tumors are characterized by a
  wide range of cellular differentiation.
• Anaplasia (cellular pleomorphism,
  hyperchromatic nuclei, high N:C ratio, giant
  cells, bizarre nuclei) is a feature of
  malignant tumors.
anaplasia
                 dysplasia
• denotes a loss of architectural organization
  and a loss of cell uniformity in epithelium
• pleomorphism and mitoses are more
  prominent than in the normal
• usually graded: mild, moderate, severe, and
  carcinoma-in-situ
• mild to moderate dysplasia is potentially
  reversible
dysplasia
normal epithelium
                 dysplasia

• Dysplasia is a non-neoplastic proliferation.
• Dysplasia may or may not progress to
  cancer.
             rate of growth
• In general, benign and well-differentiated
  malignant tumors have a slower rate of
  growth than moderately-differentiated and
  poorly-differentiated malignant tumors.
• There are exceptions. Blood supply, site,
  and hormonal stimulation are factors that
  can affect the growth rate of tumors.
                 invasion
• Benign tumors usually grow by slow
  expansion.
• Malignant tumors usually infiltrate and may
  destroy surrounding tissue (cell surface and
  the extracellular matrix play an important
  role).
                metastasis
• indicates malignancy
• a discontinuous spread of the tumor
• Methods of metastasis include: (1)seeding
  of body cavities, (2) lymphatic spread, and
  (3) hematogenous spread.
metastatic ovarian carcinoma
MRI: metastatic adenocarcinoma
metastatic adenocarcinoma
         grading and staging
• Grading is based on the microscopic
  features of the cells which compose a tumor
  and is specific for the tumor type.
• Staging is based on clinical, radiological,
  and surgical criteria, such as, tumor size,
  involvement of regional lymph nodes, and
  presence of metastases. Staging usually has
  prognostic value.
        morbidity and mortality
•   metastases
•   rupture into major vessels
•   compression of vital organs
•   organ failure
•   infection
meningioma
basal cell carcinoma
melanoma
          diagnostic procedures
•   FNA (fine needle aspiration)
•   cytological smears
•   biopsy
•   frozen sections
cytology smear: adenocarcinoma
Pap smear with dysplasia
frozen section
staining a frozen section
            ancillary studies
•   immunohistochemistry
•   cytogenetics
•   flow cytometry
•   electron microscopy
cytokeratin stain on a carcinoma
AFP stain on a yolk sac tumor
EM: neurosecretory granules
EM: microvilli, tight junction in
     an adenocarcinoma
          biochemical assays
• tumor markers: sometimes diagnostic or
  prognostic
• can be helpful in monitoring effectiveness
  of therapy or in detecting
  relapses/recurrences
    some serological markers
associated with malignant tumors
hCG              choriocarcinoma
AFP              hepatocellular ca
calcitonin       thyroid medullary ca
prolactin        pituitary adenomas
CA 125           ovarian carcinoma
PSA              prostate carcinoma
chromogranin A   endocrine neoplasias
                 summary
• neoplasia- an abnormal mass of tissue
  which has lost its responsiveness to growth
  controls
• benign neoplasms tend to be slow-growing,
  well-differentiated tumors which lack the
  ability to metastasize
• benign neoplasms, in general, remain
  localized and are amenable to surgery
                summary
• malignant neoplasms tend to be fast-
  growing lesions which invade normal
  structures
• malignant neoplasms vary in the degree of
  differentiation and some show anaplasia
• malignant neoplasms are capable of
  metastasis
                 summary
• The prognosis of a patient with any type of
  neoplasm depends on a number of factors
  including: the rate of growth of the tumor,
  the size of the tumor, the tumor site, the cell
  type and degree of differentiation, the
  presence of metastasis, responsiveness to
  therapy, and the general health of the
  patient.

				
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