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, a lumpectomy'with radiation, chemotherapy, or a combination of these treatments'is sometimes performed as an alternative to mastectomy.
