Pain in left armpit and breast. what could this be?

Physician Review: Painful nodes in the breast may or may not be significant. Any palpable nodule in the breast should be reviewed by a physician who is experienced in breast review; surgeon, OB gyn, pcp. The provider should have access to high resolution ultrasound for an in depth review of the palpable area. Treatment options range from conservative observation to surgical excision, biopsy. Seek physician review.