Axillary lymph node dissection (ALND) is a procedure in which multiple lymph nodes are removed from under the armpit (axilla) and checked for cancer spread. Most commonly, 10-20 lymph nodes are removed.

Sometimes the axillary lymph node dissection is done at the same time as another surgery for breast cancer (like a lumpectomy or mastectomy) and sometimes it is an operation that is done on its own.

ALND may be required:

  • If a previous sentinel lymph node biopsy (SLNB) has shown three or more of the underarm lymph nodes have cancer cells.
  • If swollen underarm or collarbone lymph nodes can be felt before surgery or seen on imaging tests and a biopsy shows cancer.
  • If the cancer has grown large enough to extend outside the lymph node(s) capsule (extracapsular extension).
  • If the SLNB is positive for cancer cells and a woman had chemotherapy prior to surgery.