In addition to the surgical removal of melanoma, biopsies of other areas may be needed, such as a lymph node biopsy, to determine if the melanoma has spread. Two customary lymph node biopsies are surgical lymph node biopsy and sentinel lymph node biopsy.
Surgical lymph node biopsy is performed to remove an enlarged lymph node through a small incision in the skin. Local anesthetic is generally administered prior to the biopsy. This procedure is often done if a lymph node's size suggests the spread of skin cancer.
Sentinel lymph node biopsy, or SLNB, is a staging tool, which offers valuable prognosis and treatment information. This biopsy also identifies metastatic lymph nodes and adjuvant therapy requirements. In addition, the procedure can provide criteria to place patients in adjuvant clinical trials.
To find the sentinel lymph node or nodes and perform the biopsy, a small amount of radioactive material, and sometimes a contrast material, are injected into the vicinity of the tumor. Then various lymph node areas are checked with a radioactivity detector, which works like a Geiger counter, to see what group of lymph nodes the cancer may have invaded. A small incision is then made in the identified lymph node area and the nodes are checked to find those that changed color or became radioactive. When the sentinel node has been found, it’s removed and sent to a pathologist for review. If the sentinel node reveals melanoma, additional lymph nodes from the surrounding area are removed and tested.
After any biopsy, a sample is usually sent to the lab for review. It’s looked at under a microscope for diagnosis and to see if further tests are required.