external iliac or presacral lymph node) N2 Single lymph node metastasis, more than 2 cm but not more than 5 cm in greatest dimension; or multiple lymph nodes, none more than 5 cm in greatest ...

Lymph nodes are part of the body’s immune system. A swollen lymph node in the armpit may be a sign of a bacterial or viral infection, an injury, or a serious health condition, such as cancer.