24 NCCN Guidelines for Patients ® : Melanoma, 2018 2 Tests for melanoma Lymph node tissue tests Lymph node tissue tests A biopsy is the removal of a small amount of tissue from your body to test for disease. After a skin biopsy confirms melanoma, a biopsy of the lymph nodes may be recommended to check if the cancer has spread. Lymph nodes are small groups of special disease-fighting cells located throughout the body. Lymph nodes are connected to one another by lymph vessels—tubes that carry a clear fluid called lymph throughout the body. Most melanomas are found early, when the chance that cancer cells have spread to a lymph node is small. For early melanomas, lymph node testing is usually not recommended. Your doctor will discuss this with you based on the test results in the pathology report. There is more than one type of lymph node biopsy. A lymph node biopsy may be done during surgery. Or, it may be done with a very thin needle. Which type of biopsy is recommended depends on certain factors such as whether or not there are signs of cancer spread. Types of lymph node biopsies include: Sentinel lymph node biopsy A sentinel lymph node biopsy is a surgery that removes one or more nearby (regional) lymph node(s) to test for cancer cells. The sentinel lymph node is the first lymph node to which cancer cells will likely spread from the first (primary) tumor. This type of lymph node biopsy is recommended when there’s an increased chance that the melanoma has spread to a lymph node, but the physical exam did not find any enlarged lymph nodes that may be a sign of cancer spread. It is performed to find very tiny (microscopic) cancer cells in a lymph node that cannot be found by physical exam or imaging tests. Because this is a surgical test, it is not recommended when the chance of cancer spread is very small. For this biopsy, a special dye is injected into the skin near the primary tumor. The dye follows the path the lymph takes in the lymph vessels in the area around the tumor. This allows your doctor to find the first lymph node to which lymph (and possibly a cancer cell) travels when it leaves the tumor. This is called the sentinel lymph node. The sentinel node is usually removed during the same surgery to remove the primary melanoma tumor. Possible side effects of sentinel lymph node biopsy may include numbness, pain, bruising, and lymph fluid buildup near the biopsy site. Because only one or very few lymph nodes are removed, serious side effects such as lymphedema (swelling due to fluid buildup) are rare. FNA (fine-needle aspiration) biopsy This biopsy is often used when your doctor can feel an enlarged lymph node during the physical exam. An FNA biopsy uses a very thin needle to remove small pieces of a lymph node to test for cancer cells. An anesthetic may be applied or injected to numb the area before an FNA biopsy. An FNA biopsy causes little discomfort and doesn’t leave a scar. Your doctor may use an ultrasound device or pictures from a test called a CT ( c omputed t omography) scan to guide the needle into the lymph node. Excisional lymph node biopsy An excisional lymph node biopsy removes enlarged lymph nodes through a small surgical cut in the skin. This type of biopsy may be needed if your doctor finds an enlarged lymph node during the physical exam or imaging test and an FNA biopsy isn’t possible or is unclear.