What is a Partial Mastectomy?

A partial mastectomy is a type of breast cancer surgery which involves the removal of the tumor and some of the unaffected tissue surrounding it. This procedure involves the removal of less tissue than a total mastectomy, which is the removal of the entire breast, but more tissue than a lumpectomy, which involves the removal of a very small amount of breast tissue. Partial mastectomy is sometimes also called segmental mastectomy, breast conserving surgery, or quadrantectomy because about a quarter of the breast is usually removed. This type of breast cancer surgery is one of the most common surgical treatments of breast cancer. Some reasons for choosing a partial mastectomy over procedures that involve the removal of more breast tissue include the presence of only a single tumor, a tumor that is smaller than 2 inches (5 cm) in diameter, and no family history of breast cancer.

During a partial mastectomy, the patient is fully unconscious under anesthesia. The surgeon then removes the tumor and some of the breast tissue around it, including skin, muscle, and often also some of the lymph nodes. Sometimes reconstructive surgery is performed to preserve the natural shape of the breast. After partial mastectomy surgery, fluid can collect where the incision was made, and to prevent this, drainage tubes are often inserted that are removed some days or weeks after the procedure. The patient usually undergoes six to eight weeks of radiation therapy after surgery.

A partial mastectomy is most commonly used when the breast cancer involves stage 1 or stage 2 tumors, meaning the cancer has not spread beyond the tumor, or has only spread to nearby lymph nodes but no farther. In some cases, a partial mastectomy is not the preferred treatment for breast cancer. For example, other types of surgery can be recommended if there is more than one tumor, if the tumor is large, or if the patient is not able to undergo the required radiation therapy after surgery.

There are several different types of mastectomy procedures, involving the removal of various amounts of tissue. A total mastectomy involves the removal of all breast tissue, but leaves lymph nodes and surrounding tissue intact. In a radical mastectomy the breast, some surrounding tissue, and several lymph nodes are removed. A so-called skin-sparing mastectomy involves the removal of a large amount of breast tissue through a small, keyhole-sized incision, minimizing scarring. After breast cancer surgery, the tissue surrounding the tumor is checked to determine whether the cancer has spread.