Primary ectopic breast cancer of the vulva, treated with local excision of the vulva and sentinel lymph node biopsy: a case report.

Primary breast cancer fairly infrequently occurs in ectopic breast tissue, and primary ectopic breast cancer of the vulva is particularly rare. Only 26 cases have been published in the English-language literature, and there has been no report of primary breast carcinoma of the vulva in Japan. We report a rare case of primary ectopic breast cancer of the vulva that was treated with local excision of the vulva and sentinel lymph node biopsy (SLNB).