Primary Ectopic Breast Carcinoma of the Vulva: A Case Report

A 64-year-old woman presented to the Emergency Department with acute vomiting and moderate, sharp, diffused abdominal pain, and weakness. She reported chronic Bartholin’s cyst for 1 year, which prompted gynecology consult. Investigations had revealed a primary breast carcinoma of the vulva. Surgical excision was performed, and pathology of the mass demonstrated estrogen receptor weakly positive (20%), progesterone receptor negative (<1%), and HER2 oncoprotein positive (3+). PET/CT showed metastatic disease involving retroperitoneal, bilateral iliac chain and pelvic lymph nodes and the left T12 lamina. Mammogram showed no evidence of disease, and all her prior mammograms were negative. Due to the lack of standard treatment guidelines, the patient was managed utilizing the established breast cancer treatment guidelines. The purpose of this case report is to highlight the rarity of the diagnosis of primary breast carcinoma of the vulva and the importance of including this diagnosis in differential when evaluating patients with mass lesions of the vulva.