28581 Vulvar Mammary-Like Adenocarcinoma with Overlying Extramammary Paget Disease

Observations: An 88-year old Asian female with a history of thyroid cancer presented with an itchy 5 cm erythematous inflammatory plaque on the right labia majora extending to the clitoris and left labia majora. Biopsy revealed mammary-like adenocarcinoma beneath extramammary paget disease of the vulva. Breast mammograms revealed no malignancy. The invasive dermal tumor resembled invasive ductal adenocarcinoma of the breast, being positive for cytokeratin 7 and negative for cytokeratin 20. Malignant pagetoid cells were in the epidermis. Immunohistochemical reactions found PR negative, weakly ER positive, 3+ positive for HER2, and S100 negative. Abdominal and pelvic PET/CT images revealed a hypermetabolic area only in the vulvar region. Advanced age advised against chemotherapy. The patient was treated with 4500 cGy intensity-modulated radiation therapy followed by 2160 cGy boost to the vulva and pelvic lymph nodes. A month after completion, there were no complications. She died 8 months later, cause not known.