Neoplasia-2 PDF

Neoplasia-2 Dr.Gehan Abdelmenam  Intended Learning Objectives Recall types of precancerous lesions, carcinogens and cocarcinogen. Define grade and stage of tumor. Describe mechanism of invasion and metastasis with special emphasis on angiogenesis of neoplastic tumors. Descr...

Neoplasia-2 Dr.Gehan Abdelmenam  Intended Learning Objectives Recall types of precancerous lesions, carcinogens and cocarcinogen. Define grade and stage of tumor. Describe mechanism of invasion and metastasis with special emphasis on angiogenesis of neoplastic tumors. Describe methods of spread of malignant tumors. Recall definition of Locally malignant tumors with examples. Describe definition,examples and importance of tumor markers. List Causes of death in Malignant tumors.  Precancerous lesions 1. Metaplasia: - Squamous metaplasia may lead to Squamous cell carcinoma. 2. Hyperplasia: - Endometrial hyperplasia leads to endometrial carcinoma. - Mammary hyperplasia leads to cancer breast. 3. Benign tumors: a. Thyroid adenoma change to thyroid carcinoma. b. Transitional cell papilloma change to transitional cell carcinoma. 4. Liver cirrhosis: leads to hepatocellular carcinoma. 5. Paget’s disease of bone: leads to osteosarcoma. 6. Cryptorchidism (undescended testis): leads to seminoma. 7. Xeroderma pigmentosa: leads to melanoma. Osteosarcoma on Xeroderma top of paget pigmentosa disease  Co-carcinogens - 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 related to cancer colon smoked fish related to cancer stomach 4. Environmental factors: a. Cigarette smoking related to cancer tongue, larynx, lung, kidney and urinary bladder. b. Alcoholism: cancer mouth and esophagus. c. Excess sun exposure: related to cancer skin. 5. Heredity: Some tumors are inherited i.e. cancer breast and cancer colon  Chemical carcinogens A B B C A. Beta-naphthylamine (paints) cancer bladder. B. Aflatoxins produced from aspergillus fungus cancer liver. C. Nitrosamine(preservative substance) cancer stomach. 2. Viral carcinogens: Hepatitis B virus hepatocellular carcinoma. Human papilloma virus (HPV) cancer cervix. Epstein bar virus (EBV) nasopharyngeal carcinoma and lymphoma. Nasopharyngeal carcinoma 3. Radiation carcinogens: a. Ionizing radiation: leukemia. b. Ultraviolet rays ,prolonged exposure 4. to Hormonal carcinogens: sunlight: cancer skin. a. Estrogen: cancer breast and cancer endometrium. b. Androgen: cancer prostate.  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).  Tumor Staging Assessment of the degree of infiltration of the tumor to the underlying tissue. TNM staging system; 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 Tumor embolus inside a vess 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 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 lower lip to upper lip. Locally malignant tumors  Locally malignant tumors * Definition: groups of malignant tumors that spread only locally with no distant spread. Examples: 1. Basal cell carcinoma (skin) 2. Osteoclastoma (bone) 3. Adamantinoma (tibia,jaw). 4. Astrocytoma (brain) Basal cell carcinoma Adamantinoma  Tumor Markers * Def: Substances produced by the neoplastic cells and can be demonstrated in cells, serum, or body fluids. * Importance: They are used to: 1. Support diagnosis (they are not used as primary modalities for diagnosis of cancer). 2. Assessment of cancer therapy. 3. Follow up. * Examples: PSA for cancer prostate, CA-125 for cancer ovary, CA-15-3 for cancer breast,CA-19-9 for pancreatic cancer, alpha- fetoprotein&Hep par- 1 with hepatocellular carcinoma, HMB-45 with melanoma.  Causes of death in Malignant tumors 1. Destruction of vital tissues such as brain, liver, kidney. 2. Obstructive effects e.g. urinary tract obstruction. 3. Malnutrition due to interference of food intake, digestion and absorption. 4. Severe anemia. 5. Malignant cachexia: loss of weight & weakness due to muscle wasting. - It is associated with depressed immunity.  REFERENCES Robbins and Cotran Pathologic Basis of Disease, 9th edition, 2014 ( Kumar, Abbas, Aster) Robbins Basic Pathology 10th edition, 2017 ( Kumar, Abbas, Aster)