A mastectomy is surgery to remove all the breast tissue from one or both breasts. It is most commonly performed to treat breast cancer, though some people choose it preventively when they carry a high genetic risk. The specific type of mastectomy, how many lymph nodes are removed, and whether reconstruction happens at the same time all depend on the reason for surgery and the characteristics of the cancer.
Types of Mastectomy
Not all mastectomies are the same procedure. The differences come down to how much tissue, skin, and lymph node involvement the surgeon addresses.
A simple (total) mastectomy removes all of the breast tissue, the breast skin, the nipple, and the areola. When breast cancer is the reason for surgery, the surgeon typically also removes one to three lymph nodes from the armpit to check whether cancer has spread. This limited sampling is called a sentinel lymph node biopsy.
A modified radical mastectomy goes further. In addition to removing all breast tissue, skin, nipple, and areola, the surgeon removes between 10 and 40 lymph nodes from the armpit. This is called an axillary lymph node dissection and is done when there are signs that cancer has reached the lymph nodes.
A skin-sparing mastectomy removes all the breast tissue and the nipple but leaves most of the outer skin intact. This makes immediate breast reconstruction easier because the natural skin envelope is preserved.
A nipple-sparing mastectomy removes all the breast tissue while keeping the nipple, areola, and breast skin in place. The cosmetic result tends to be the most natural-looking, but not everyone is a candidate. People with inflammatory breast cancer, cancer involving the nipple, or tumors very close to the nipple are generally not eligible. Factors like tumor size over 2 cm, a tumor sitting less than 4 cm from the nipple, and certain aggressive cancer markers increase the chance that the nipple tissue itself harbors cancer cells.
Why a Mastectomy May Be Recommended
A mastectomy is one of two main surgical options for breast cancer. The other is a lumpectomy, which removes only the tumor and a margin of surrounding tissue. Your doctor may recommend mastectomy instead of lumpectomy when the cancer or precancerous area (DCIS) is large relative to the breast size, when a previous lumpectomy didn’t fully clear the cancer margins, or when you have inflammatory breast cancer.
A double mastectomy, removing both breasts, may be recommended if cancer is present in both breasts or if you have cancer in one breast combined with a high risk of developing it in the other. That high risk often comes from carrying a BRCA1 or BRCA2 gene variant or having a strong family history of breast cancer.
Some people without a current cancer diagnosis choose a preventive (prophylactic) bilateral mastectomy to sharply reduce their future risk. For women with a harmful BRCA1 or BRCA2 variant, bilateral mastectomy reduces the risk of breast cancer by at least 95%. For those with a strong family history but no identified gene variant, the reduction is up to 90%.
What Happens During Surgery
Mastectomy is performed under general anesthesia. The surgeon removes the breast tissue through an incision and, in most cancer cases, also checks the lymph nodes. For sentinel lymph node biopsy, the surgeon injects a radioactive tracer, a blue dye, or both near the tumor before making the incision. These substances travel through the lymphatic system and collect in the first nodes that drain the breast. The surgeon locates those nodes using a handheld detector or by looking for blue-stained tissue, removes them, and sends them to a pathologist.
If the pathologist finds cancer cells in those sentinel nodes, additional lymph nodes may be removed either during the same operation or in a follow-up procedure. Large clinical trials have shown that when sentinel nodes are cancer-free, removing further lymph nodes offers no added benefit for staging or preventing recurrence.
Most people undergoing mastectomy stay in the hospital overnight for observation and go home the next day. Surgical drains, small tubes placed under the skin to collect fluid, are common and typically stay in place for one to two weeks after surgery.
Recovery and Physical Restrictions
The recovery timeline varies depending on whether you had reconstruction at the same time and how many lymph nodes were removed. For a mastectomy without reconstruction, you can return to low-impact exercise once your pain is controlled and you feel comfortable. Avoid heavy lifting on the surgical side for four weeks.
If you had an axillary lymph node dissection, avoid repetitive arm motions on that side, like vacuuming, for two weeks. Heavy lifting restrictions still apply for four weeks. If you had reconstruction, the timeline is longer: low-impact exercise typically resumes four weeks after surgery, and you should not lift your arm above shoulder level until your plastic surgeon clears you. Four weeks after the incision heals, gentle self-massage of the scar area can begin.
Common Complications
The most frequent complication after mastectomy with lymph node removal is a seroma, a pocket of fluid that collects under the skin where tissue was removed. In studies of patients undergoing mastectomy with axillary lymph node dissection, roughly one in four developed a seroma. Surgical drains remain the most effective way to prevent this, and removing drains too early nearly doubles the risk.
Lymphedema, chronic swelling in the arm on the surgical side, is a longer-term concern, particularly after extensive lymph node removal. It happens because removing lymph nodes disrupts the body’s normal fluid drainage pathways. The risk is much lower with sentinel node biopsy alone than with full axillary dissection.
Breast Reconstruction Options
Reconstruction can happen during the same surgery as the mastectomy (immediate) or months to years later (delayed). The two main approaches are implant-based reconstruction and autologous tissue reconstruction, which uses tissue transplanted from another part of your body, most often the abdomen.
Implant reconstruction involves a shorter surgery, roughly two hours less on average. Short-term complication rates are similar between the two approaches. However, implants carry a higher rate of long-term complications, including capsular contracture (hardening of scar tissue around the implant) and implant failure that may require additional surgeries over time.
Autologous tissue reconstruction, where a flap of skin, fat, and sometimes muscle is moved from the abdomen or back to create a new breast mound, consistently scores higher on patient satisfaction. In a large review of over 3,000 women, those who had tissue-based reconstruction reported better psychosocial well-being, sexual well-being, and overall satisfaction with how the breast looked, felt, and fit in clothing compared to those with implants. The trade-off is a longer, more complex surgery with its own recovery at the donor site.
Not everyone chooses reconstruction. Some people prefer to use a prosthetic breast form, and others choose to go flat. The decision is personal, and there is no medical requirement to reconstruct after mastectomy.