A mastectomy is the surgical removal of the breast. It is used to treat breast cancer.

• Partial or segmental mastectomy is the removal of the area of the breast that contains cancer, some of the breast tissue around the tumor, and the lining over the chest muscles below the tumor. The lymph nodes under the arm are also removed and examined under a microscope (axillary lymph node dissection or sentinel node biopsy).
• Total (or simple) mastectomy is the removal of the whole breast.
• Modified radical mastectomy is the removal of the breast, the lymph nodes under the arm, the lining over the chest muscles, and sometimes part of the chest wall muscles.
• Skin-sparing mastectomy leaves most of the skin that was over the breast, except for the nipple and the areola. This type of mastectomy removes about as much breast tissue as a modified radical mastectomy, but leaves less scar tissue and a reconstructed breast that seems more natural.
• Radical mastectomy (Halsted radical mastectomy) is the removal of the breast, chest muscles, and all of the lymph nodes under the arm. For many years, this was the most common operation for breast cancer, but now it is rarely used.

The removal of the breast before cancer is diagnosed is called a prophylactic mastectomy. This type of mastectomy can be used to prevent breast cancer in women who have an extremely high risk of developing the disease.

By	Healthwise Staff
Primary Medical Reviewer	Joy Melnikow, MD, MPH - Family Medicine
Specialist Medical Reviewer	Douglas A. Stewart, MD - Medical Oncology
Last Revised	August 18, 2009