Saturday, November 28, 2009

Classification of Cancerous Tumors

It is possible to divide these types of cancer into three broad groups on the basis of histogenesis that is, by identifying the particular type of tissue (hist/o) from which the tumor cells arise ( -genesis ). These major groups are carcinomas , sarcomas , and mixed tissue tumors.

Carcinomas

Carcinomas, the Largest group , are solid Tumors that are derived from etithelial tissue that lines external and internal body surfaces, including skin , glands , and digestive , urinary , and reproductive organs.

Sarcomas

Sarcomas are less common (less than 5 percent of all malignant tumors ) than carcinomas and are derived from connective tissues in the body, such as bone, fat, muscle, cartilage, and bone marrow and from cells of the lymphatic system.


PATHOLOGICAL DESCRIPTIONS

The following terms are used to descripe the apperance of a maligant tumor, on either gross (visual) or on microscopic examination

Cystic

Forming large open spaces filled with fluid.Mucinous tumors are filled with mucus (thick, sticky fluid ), and serous tumors are filled with a thin, watery fluid resembling serum. The most common site of cystic tumors is in ovaries.

Fungating

Mushrooming pattern of growth in which tumor cells pile one on top another and project from a tissue surface. Tumors found in the colon are often of this type.

Inflammatory

Having the features of inflammation ; that is, redness, sweling, and heat. Inflammatory changes result from tumor blockage of the lymphatic drainage of the skin, as in breast cancer.

Medullary

Pertaining to large, soft, fleshy tumors. Thyroid and breast tumors may be medullary.

Necrotic

Containing dead tissue. Any type of tumor can outgrow its blood supply and undergo necrosis.

Polypoid

Growths that are like projecttions extending outward from a base. Sessile polypoid tumors extend from a broad base, and pedunculated polypoid tumors extend from a stem or stalk. Both benign and maligant tumors of the colon may grow as polyps

Ulcerating

Characterized by an open, exposed surface resulting from the death of overlying tissue. Ulcerating tumors are often found in the sromach, breast, colon, and skin.

Verrucous

Resembling a wart-like growth. Tumors of the gingiva (cheek ) are frequently verrucous.

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