DIAGNOSIS OF TUMORS The final diagnosis of any tumor is usually based on the histological examination using the following ways: Frozen section. Paraffin section. Exfoliative cytology (based on the fact that the tumor cells are shed off and appear in exudates and secretions. 4. Tumor markers: These are markers present in blood or tissues […]
ETIOLOGY OF TUMORS The actual cause of tumors remains obscure up till now. However many pre-disposing factors known as carcinogenic agents, appear to play a certain role in the development of certain tumor. These factors are: 1) Chemical carcinogens: The hydrocarbons: the development of carcinoma of the scrotum in chimney sweepers was observed very […]
EMBRYONIC TUMORS These are usually malignant tumors which arise in children and are formed of malignant cells that resemble the embryonic cells which are initially present in the particular part of the body from which the tumor arises. These tumors are: Nephroblastoma (Wilm’s tumor) in kidney. Neuroblastoma in adrenal medulla. Medulloblastoma in cerebellum. […]
TUMORS OF PIGMENTED CELLS Nevus or pigmented mole: It is a benign tumor of melanocytes of the skin of the face, neck and chest. It is present in nearly everyone and usually dates since birth and so now it is considered as hamartomatous malformation. Types: Junctional nevus: appears as a flat brown lesion in […]
TUMORS OF VESSELS Benign Hemangioma: It is a benign tumor of blood vessels. It appears since birth and it is now considered as hamartomatous malformation. It is of two types: a) Capillary hemangioma: This usually appears in the skin as irregular red patch, not raised above the level of skin. Microscopically: It is formed of […]
MALIGNANT MESENCHYMAL TUMORS Sarcoma: – It is a malignant tumor arising from mesodermal tissues as connective tissues, muscles and lymphoid tissues. Classification of sarcoma I- Cytological classification: i.e. according to the shape and form of the sarcoma cells. It is only used in highly undifferentiated sarcomata where their origin cannot be definitely known from […]
TUMORS OF MUSCLE I- Benign: Leiomyoma: it is a benign tumor of smooth muscles. The commonest site is uterus where it is some times called “fibromyoma”, less common it occurs in the stomach and intestine. Rhabdomyoma: it is a rare benign tumor of striated muscles. II- Malignant: In the form of sarcoma e.g. leiomyosarcoma, rhabdomyosarcoma.
BENIGN MESENCHYMAL TUMORS Fibroma It is a benign tumor arising from fibrous tissue. It appears as rounded or oval, well encapsulated firm tumor of variable size. The cut surface shows interlacing whitish bundles of fibrous tissue. Microscopically: It is formed of dense collagen bundles with large numbers of fusiform fibroblasts. Sites: Skin and subcutaneous […]