What is a sentinel lymph node biopsy?

A sentinel lymph node biopsy is a test that checks lymph nodes for cancer cells. Lymph nodes are part of the lymphatic system, a network of organs and vessels that help the body fight infections and other diseases. Lymph nodes are located throughout the body, including the underarms, neck, chest, abdomen, and groin.

Certain cancers, such as breast cancer and melanoma (the most dangerous form of skin cancer), can spread through the lymphatic system. Cancers spread when cells break off from the original tumor and are carried to other parts of the body. The sentinel lymph node is the first node where these types of cancers are most likely to spread. The node is usually located near the site of the original tumor. Sometimes there is more than one sentinel lymph node.

A sentinel lymph node biopsy can show how likely it is that your cancer is spreading (metastasizing).

Other names: lymph node biopsy, sentinel node biopsy, sentinel lymph node mapping and biopsy