![Lymphoscintigraphy in the armpit being operated on.](http://static.sciencelearn.org.nz/images/images/000/001/638/full/Sentinel_lymph_node_%28axilla%29.jpg?1676947287)
Lymphoscintigraphy showing a sentinel lymph node in the armpit. A radioactive tracer has been injected at the tumor site in order to identify the sentinel node(s). A blue tracer dye has also been used for greater accuracy of identification. The node will be removed and biopsied.