Neoplasia-2

Precancerous lesions Metaplasia: 2. Benign tumors: Squamous metaplasia Squamous cell carcinoma. Glandular metaplasia Adenocarcinoma. 2. Benign tumors: Thyroid adenoma thyroid carcinoma. Transitional cell papilloma transitional cell carcinoma.

4. Liver cirrhosis: leads to hepatocellular carcinoma. 3. Hyperplasia: Endometrial hyperplasia leads to endometrial carcinoma. Mammary hyperplasia leads to cancer breast. 4. Liver cirrhosis: leads to hepatocellular carcinoma. 5. Paget’s disease of bone: leads to osteosarcoma. 6. Crytorchidism (undescended testis): leads to seminoma. 7. Xeroderma pigmentosa: leads to melanoma.

Co-carcinogens 1. Age: 2. Sex: 3. Diet: - Means the factors help the occurrence of cancer. 1. Age: - With aging there is a more chance of exposure to the carcinogen. 2. Sex: Most of tumors are common in male. 3. Diet: Excess fat may be related to cancer colon. Smoked fish may be related to cancer stomach.

4. Environmental factors: a. Cigarette smoking related to cancer tongue, larynx, lung, kidney and urinary bladder. b. Excess sun exposure: related to cancer skin. c. Alcoholism: cancer mouth and esophagus. 5. Heredity: Some tumors are inherited i.e. cancer breast and cancer colon

Carcinogenic agents Chemical carcinogens: Beta-naphthylamine cancer bladder. Aflatoxins produced from aspergillus fungus liver cancer. Nitrosamine cancer stomach.

2. Viral carcinogens: Hepatitis B virus hepatocellular carcinoma. Human papilloma virus (HPV) cancer cervix. Ebstein barr virus (EBV) nasopharyngeal carcinoma and lymphoma.

3. Radiation carcinogens: a. Ionizing radiation: leukemia. b. Ultraviolet rays (prolonged exposure to sunlight): cancer skin. 4. Hormonal carcinogens: a. Estrogen: cancer breast and cancer endometrium. b. Androgen: cancer prostate.

Morphology of Malignant tumors

Carcinoma is malignant tumor arising from epithelium. 8/1/1433 Carcinoma is malignant tumor arising from epithelium. * Examples: Squamous epithelium  squamous cell carcinoma. Glandular epithelium  adenocarcinoma. Transitional epithelium  transitional cell carcinoma.

Squamous cell carcinoma of the skin 8/1/1433 Squamous cell carcinoma of the skin 1 1. This is a squamous cell carcinoma arising on the dorsum of the hand. Besides sun exposure, risk factors for squamous cell carcinoma arising in skin include carcinogens such as tars, chronic ulcers, burn scars, arsenic poisoning, and radiation exposure. In this case there was a history of both sun exposure as well as exposure to carcinogens. 2. Squamous Cell carcinoma arising from chronic sinus that was draining osteomyelitis of humerus The normal squamous epithelium at the left merges into the squamous cell carcinoma at the right, which is infiltrating downward. The neoplastic squamous cells are still similar to the normal squamous cells, but are less orderly. This is a well-differentiated squamous cell carcinoma. 3 2

Colonic adenocarcinoma 8/1/1433 Colonic adenocarcinoma The infiltrating glands of this colonic adenocarcinoma

Sarcoma is malignant tumor arising from mesenchymal tissue. 8/1/1433 Sarcoma is malignant tumor arising from mesenchymal tissue. * Examples: Bone: osteosarcoma. Cartilage: chondrosarcoma. Fibrous tissue: fibrosarcoma. Fat: liposarcoma. Smooth muscle: leiomyosarcoma. Striated muscle: rhabdosarcoma.

Tumor Grading (Differentiation) 8/1/1433 Tumor Grading (Differentiation) Assessment of the degree of similarity between the tumor and its parent tissue. Tumors may be: Well differentiated (grade I). Moderately differentiated (grade II). Poorly differentiated tumors (grade III). Undifferentiated tumors (grade IV).

Poorly differentiated Squamous cell carcinoma 8/1/1433 Well Differentiated Moderately differentiated B Poorly differentiated A: Well-differentiated SCC B: Moderately diff. SCC C: Poorly-diff. SCC Squamous cell carcinoma C

Tumor Staging Assessment of the degree of infiltration of the tumor to the underlying tissue. Includes 3 parameters: T (primary tumor): Tis, T1, T2, T3, T4 N (regional lymph nodes): N0, N1, N2, N3 M (metastasis): M0, M1

Spread of malignant tumors

I. Local (direct) spread: The malignant cells infiltrates the surrounding extracellular matrix in all directions and invade the surrounding structures.

II. Distant spread (metastasis): 1. Lymphatic spread: The tumor cells invade the walls of lymphatics and pass with the lymph to the draining lymph nodes. 2. Blood spread: The tumor cells invade the wall of blood vessels and pass inside the circulation as tumor emboli to reach distant organs.

3. Transcoelomic spread: the tumor cells invades the covering serous membranes and pass between the visceral and parietal layers to a distant organ e.g. from the gastric carcinoma to both ovaries (Kruckenberg’s tumor) 4. Spread by implantation: spread of tumor cells between two opposing surfaces e.g. from upper lip to lower lip.

Locally malignant tumors

* Definition: * Examples: Groups of malignant tumors that spread only locally with no distant spread. * Examples: Basal cell carcinoma (skin) Osteoclastoma (bone) Adamantinoma (mandible). Astrocytoma (brain).

Tumor Markers

* Importance: They are used to: * Def: Substances produced by the neoplastic cells and can be demonstrated in cells, serum, or body fluids. * Importance: They are used to: Support diagnosis (they are not used as primary modalities for diagnosis of cancer). Assessment of cancer therapy. Follow up. * Examples: PSA for cancer prostate, CA-125 for cancer ovary, CA-15-3 for cancer breast…..

Immunohistochemical diagnosis of tumors

They detect the type tumors using their specific monoclonal antibodies. Examples: Desmin for muscle tumors Cytokeratin (CK) and epithelial membrane antigen (EMA) for epithelial tumors Leucocyte common antigen (LCA) for lymphoma. CD20 for B cell lymphoma. CD3 for T cell lymphoma.

Positive CD20 in a case of B. cell lymphoma

Causes of death in Malignant tumors

Destruction of vital tissues such as brain, liver, kidney. Malnutrition due to interference of food intake, digestion and absorption. Obstructive effects e.g. urinary tract obstruction. Severe anemia. Malignant cachexia: wasting, loss of weight and muscular weakness with depressed immunity.

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