Dictionary

masseter The muscle that raises the lower jaw.

mast cell A granulocyte found in connective tissue whose normal function is unknown but that is frequently injured during allergic reactions. When a mast cell is injured, it releases strong chemicals, including histamine, into the tissues and blood. These chemicals are very irritating and cause itching, swelling, and fluid leaking from cells. They can also…

mastalgia Pain in the breast or mammary gland, whether serious or not. Mastalgia has many causes including injury, infection, and plugged milk ducts.

mastectomy A general term for removal of the breast, usually to remove cancerous tissue. The operation can be done in a hospital or in an outpatient clinic, depending on how extensive it needs to be. After a mastectomy, reconstructive surgery may be performed to restore a more normal appearance. In cases of nonmetastatic breast cancer,…

mastectomy, double Removal of both breasts.

mastectomy, Halsted A radical mastectomy. See mastectomy, radical.

mastectomy, modified radical Removal of the breast tissue and the axillary lymph nodes, which are under the arms.

mastectomy, partial Surgical removal of only enough breast tissue to be sure that the margins of the tissue removed are free of cancer. Also known as segmental mastectomy.

mastectomy, preventive Removal of one or both breasts without the current presence of cancer. This surgery is sometimes chosen as a preventive measure by women who have a strong family history of breast cancer.

mastectomy, prophylactic See mastectomy, preventive.

mastectomy, radical Removal of all breast tissue, from just under the collarbone to the abdomen, including the chest wall muscles and the axillary lymph nodes in the armpit. In a trial begun in 1971, the efficacy of radical mastectomy was compared with that of total mastectomy. This historic trial spelled the end of radical mastectomy…

mastectomy, segmental A partial mastectomy. See mastectomy, partial.