MT training : cancer medicine

Sarcomas are less common than carcinomas and are derived from supportive and connective tissue, such as bone, fat, muscle, cartilage, and bone marrow, and from cells of the immune (lymph) system. Sarcomas account for approximately 5 percent of all malignant neoplasms.

· Benign tumors of connective tissue origin are named by adding the suffix—oma to the type of tissue in which the tumor occurs. For example, a benign tumor of bone is called an osteoma.

· Malignant tumors of connective tissue origin are often named by using sarcoma (sarc/o means flesh) added to the type of tissue in which the tumor occurs. For example, an osteosarcoma is a malignant tumor of bone.

Mixed tissue Tumor

Mixed-tissue tumors are derived from tissue that is capable of differentiating into both epithelial and connective issue. These uncommon tumors are thus composed of several different types of cells. Examples of mixed-tissue tumors can be found in the kidney, ovaries, and testes.

II. Pathological Descriptions

The following terms are used to describe the appearance of a malignant tumor, either on gross (visual) or on microscopic examination.

Gross Descriptions

Cystic	Forming large open spaces filled with fluid. Mucinous tumors are filled with mucus (thick, sticky fluid), and serous tumors are filled with thin, watery fluid resembling serum. The most common site of cystic tumors is on ovaries.
Fungating	Mushrooming pattern of growth in which tumor cells pile one on top of another and project from a tissue surface. Tumors found in the colon are of this type.
Inflammatory	Having the features of inflammation; that is, redness, swelling, and heat. These tumors characteristically occur in the breast.
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 projections 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 malignant tumors of the colon may grow as polyps.

Ulcerating	Characterized by an open, exposed surface resulting from death of overlying tissue. Ulcerating tumors are often found in the stomach, breast, colon, and skin.
Verrucous	Resembling a wart-like growth. Tumors of the gingiva (cheek) are frequently verrucous.

Microscopic Descriptions

Alveolar	Tumor cells form patterns resembling small, microscopic sacs; commonly found in tumors of muscle, bone fat, and cartilage.
Carcinoma in situ	Referring to localized tumor cells that have not invaded adjacent structures. Cancer of the cervix may begin as carcinoma in situ.
Diffuse	Spreading evenly throughout the affected tissue. Malignant lymphomas may display diffuse involvement of lymph nodes.
Dysplastic	Pertaining to abnormal formation of cells. These tumors display a highly abnormal but not clearly cancerous appearance. Dysplastic nevi (moles on skin) are an example.
Epidermoid	Resembling squamous epithelial cells (thin, plate-like), often occurring in the respiratory tract.

Radiation

The goal of radiation therapy is to deliver a maximal dose of ionizing radiation to the tumor tissue and a minimal dose to surrounding normal tissue. In reality, this goal is difficult to achieve, and usually one accepts a degree of residual normal cell damage (morbidity) as a side effect of the destruction of the tumor. High-dose radiation produces damage to DNA.

Some terms used in the field of radiation therapy for cancer are listed below

Electron beams	Low-energy beams for treatment of sin or surface tumors.
Fractionation	A method of giving radiation in small, repeated doses rather than a few large doses. Fractionation allows larger total doses to be given with less damage to normal tissue.
Linear Accelerator	A large electronic device that produces high-energy x-ray beams for treatment of deep-seated tumors.
Radiocurable Tumor	Tumor that can be completely eradicated by radiation therapy. These are usually localized tumors with no evidence of metastasis. Metastasis. Lymphomas and Hodgkin’s disease are examples
Radioresistant Tumor	Tumor that requires large doses of radiation to produce death of cells. The high doses of radiation may have a damaging effect on Surrounding normal tissue. Connective tissue tumors are the most radio resistant.
Radiosensitive Tumor	Tumor in which irradiation can cause death of cells without serious damage to surrounding normal tissue.
Radiosensitizers	Drugs that increase the sensitivity of tumors to x-rays.