Primary ectopic breast cancer presenting as a vulvar mass

Ectopic breast tissue is found along the primitive embryonic milk lines, which extend from the axilla to the groin. Rarely, its occurrence has been described in the vulva. We report a patient who developed primary adenocarcinoma of ectopic breast tissue in such a location and present a review of the pertinent medical literature. The predominant pathology is that of invasive ductal carcinoma; however, other tumor types have also been reported in accessory breast tissue. Its treatment usually entails surgical resection with lymph node dissection. Adjuvant therapy should be guided by the same principles as in orthotopic breast carcinoma.