Sentinel lymph node

A sentinel lymph node is the first lymph node to which cancer cells are likely to spread from a primary tumor. During a procedure, a special dye or radioactive substance is injected near the tumor to identify this key node. Removing and examining the sentinel node helps doctors determine if cancer has started to spread, guiding treatment decisions. It's a minimally invasive way to assess the spread of certain cancers, such as breast cancer or melanoma, and can help avoid more extensive lymph node removal if the sentinel node is free of cancer.