Lymph Node Mapping

**Semantic type:** Diagnostic Procedure

**Definition:** Lymph Node mapping, also known as sentinel lymph node (SLN) mapping is a procedure in which a radioactive tracer and a blue dye is injected around the tumor site. These two substances travel from the tumor and drain into the sentinel, or main, lymph node. Together they provide a marker for the location and presence of a sentinel lymph node, allowing discovery of minute metastases areas.

**Synonyms:** - lymph node mapping - lymphatic mapping