Infiltrating Mammary Duct Adenocarcinoma in the Right Labia Majora Along the Milk-Line.

Introduction Breast tissue rarely arises from the vulva and malignancy might develop in it. Case Thirty-eight-year-old woman presented with a suspicious ulcer in the right labia majora discovered accidently and removed by wide local excision. Histopathology revealed infiltrating mammary duct adenocarcinoma along the milk line. Immunohistochemistry was positive for estrogen and progesterone receptors and equivocal overexpression for HER2 protein with a score of 2+. Metastatic work-up was clear. Inguinal lymph nodes were enlarged and lymphadenectomy done which showed positive lymph nodes on the right side and none on the left. She is receiving adjuvant therapy. Conclusion Mammary duct carcinoma along the nipple line is rare but should be considered when dealing with suspicious vulvar lesions.