Cluster of lymph nodes at armpit?

The cluster of lymph nodes at the armpit is called the axillary lymph nodes. The axillary lymph nodes are located in the axilla (armpit) and drain lymph from the breast, shoulder, and upper arm. The axillary lymph nodes are important in the body's immune system and can become swollen or enlarged when there is an infection or other medical condition in the breast or upper limb.