Neoplasia I Introduction

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Neoplasia IIntroduction

• Husni Maqboul, M.D.

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Terminology

• Tumor Pathologic disturbance of growth,
  characterized by excessive and unnecessary
  proliferation of cells
• Galen (131 - 201 AD )
• Swelling according to nature ( pregnancy )
• Swelling exceeding nature ( Callus )
• Swelling contrary to nature

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Terminology

• Hamartoma Excessive but focal overgrowth of
  cells and tissues native to the organ in which it
  occurs. Cellular elements are mature, but do not
  produce normal architecture
• Hamartroma of lung
• Angiomas
• Pigmented nevi

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Terminology

• Choristoma (Heterotopia) Normal cells or
  tissues, that are present in abnormal locations
• Pancreatic cells in the wall of stomach or
  intestine
• Nests of adrenal cells in kidney , lung or ovaries

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Terminology

• Neoplasms Persistent , abnormal and relatively
  autonomous proliferation of cells occurring as a
  result of permanent cellular defect that is
  passed to the progeny. Usually develops due to a
  factor(s) , but once developed , becomes
  independent of them.

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Types of neoplasms

• Neoplasms
• Parenchyma made up of neoplastic cells
• Supporting host derived stroma
• 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

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Examples of benign tumors

• Epithelial
• Adenoma benign glandular tumor
• Papilloma benign surface epithelial tumors
• Polyp benign tumor projecting over mucosal
  surface
• Cystadenoma benign epithelial tumor forming
  hollow cystic mass

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Examples of benign tumors

• Mesenchymal
• Chondroma benign cartilaginous tumor
• Leiomyoma benign smooth muscle tumor
• lipoma benign tumor of fat
• Fibroma benign tumor of fibrous tissue
• Mixed
• Benign Mixed Tumor divergent differentiation of
  stem cell (pleomorphic adenoma)
• Fibroadenoma neoplastic fibrous component
• More than one germ cell layer
• Benign teratoma mature components

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leiomyomas
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adenoma
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Examples of malignant tumors

• Sarcoma (mesenchymal derivation fibrosarcoma,
  chondrosarcoma)
• Carcinoma (epithelial derivation adenocarcinoma,
  squamous cell carcinoma)
• Squamous
• Adeno
• Transitional
• Lymphoma/leukemia

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adenocarcinoma
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carcinoma
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• The terms benign and malignant describe the
  biologic behavior of a tumor
• The biologic behavior is characterized by degree
  of differentiation of the tumor , rate of growth
  (and rate of cell death) , infiltration of
  surrounding tissue, and dissemination to distant
  sites

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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)

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well-differentiated
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poorly-differentiated
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Differentiation

• 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 NC ratio, giant cells, bizarre
  nuclei) is a feature of malignant tumors.

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anaplasia
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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

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normal epithelium
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dysplasia
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Dysplasia

• Dysplasia is a non-neoplastic proliferation.
• Dysplasia may or may not progress to cancer.

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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.

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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).

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Functional characteristics

• Benign tumors are more likely to function
• Epithelial tumors can produce mucin
• Hormonal production can be unregulated
• Inappropriate production of hormones by different
  type of cells
• Abnormal receptor and antigenic expression

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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.

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metastatic ovarian carcinoma
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MRI metastatic adenocarcinoma
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metastatic adenocarcinoma
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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 more
  prognostic value.

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Morbidity and mortality

• metastases
• rupture into major vessels
• compression of vital organs
• organ failure
• infection

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meningioma
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basal cell carcinoma
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melanoma
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Diagnostic procedures

• FNA (fine needle aspiration)
• Cytological smears
• Biopsy
• Frozen sections
• Biochemical assays
• Molecular diagnosis
• Flow cytometry

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cytology smear adenocarcinoma
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Pap smear with dysplasia
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frozen section
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staining a frozen section
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Ancillary studies

• Immunohistochemistry
• Cytogenetics
• Flow cytometry
• Electron microscopy

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cytokeratin stain on a carcinoma
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AFP stain on a yolk sac tumor
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EM neurosecretory granules
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EM microvilli, tight junction in an
adenocarcinoma
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Biochemical assays

• Tumor markers sometimes diagnostic or
  prognostic
• Can be helpful in monitoring effectiveness of
  therapy or in detecting relapses/recurrences

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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

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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

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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.