Primary ectopic breast cancer of the axilla.

Ectopic breast cancer in the axilla may be misdiagnosed as a lipoma, enlarged lymph node, sebaceous cyst, or as hidradenitis suppurativa. We report a case of ectopic breast cancer and review the literature regarding the pathophysiology, prognosis and treatment of this disease. The case demonstrates how it is imperative that one include cancer in the differential diagnosis when evaluating an axillary mass.