Modified radical mastectomy is a type of surgery usually performed for breast cancer in which the entire breast is removed, including the skin, areola, nipple, and most axillary lymph nodes, but the underlying pectoralis major muscle is spared. In contrast, a simple mastectomy removes the breast, skin, areola, and nipple but not most of the lymph nodes. Other options for surgical removal of breast cancers include breast-conserving surgery or lumpectomy, which is a removal of part of the breast tissue only. Other types of mastectomy procedures include skin-sparing or nipple-sparing mastectomy.
Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.