mastectomy (măstĕk´təmē), surgical removal of breast tissue, usually done as treatment for breast cancer. There are many types of mastectomy. In general, the farther the cancer has spread, the more tissue is taken. The radical mastectomies of the past (which removed not only the breast, but underlying chest muscle and lymph nodes) have largely been replaced by less drastic, but equally effective procedures. For small tumors, lumpectomy, removing just the tumor and a margin of tissue, may be performed. A partial, or segmental, mastectomy removes the cancer, some breast tissue, the lining over the chest, and usually some lymph nodes from under the arm; total or simple mastectomy removes the whole breast; modified radical mastectomy takes the breast, lining over the chest muscles, and lymph nodes.
Breast reconstruction can be done using the patient's own tissue or breast implants. Mammograms and self-conducted breast exams have done much to reduce the need for radical procedures because they have increased early detection of the cancer, allowing it to be treated before it has spread.