All types of surgery have the following potential complications:
Adverse reaction to general anesthesia. Serious consequences of this complication are very rare (e.g., 1 death in 200,000 surgeries).
The three potential main complications that are specifically associated with a lumpectomy surgery include:
Loss of sensation in some areas of the breast. If this occurs, usually some of the sensation will return in time.
Sometimes following a lumpectomy, the breasts may appear mismatched. Because some tissue is removed from the affected breast during the surgical procedure, the treated breast may appear smaller than the untreated breast.
Lymphedema, which is a swelling under the arm caused by reduced ability of lymph nodes to drain. The swelling may be accompanied by numbness, discomfort, and sometimes infection.