For many patients with a melanoma thicker than 1 mm, SNB is a useful way to find out whether the cancer has spread from where it began. It helps your doctor plan treatment and can help you understand your prognosis. There are few side effects from the procedure, but a patient may experience infection, seroma (fluid build-up) near the surgical area, numbness, and re-opening of the surgical area. Rarely, lymphedema (build-up of lymph fluid) may occur. However, this side effect is more common for patients who have had a lymph node dissection.

If melanoma is found in the sentinel lymph nodes, a lymph node dissection to remove the remaining lymph nodes in that area allows the doctors to find out whether the cancer has spread and remove any additional lymph nodes that may contain melanoma. A patient may take longer to recover after a lymph node dissection and has a higher risk of side effects. For example, a patient who has had a lymph node dissection in the armpit or groin has a higher risk of lymphedema. However, the results of a lymph node dissection help your doctor make sure you get the appropriate treatment for your stage of melanoma. Talk with your doctor about the tests needed to diagnose melanoma and determine the stage, and how these results affect your treatment options.