Adnexal Clear Cell Carcinoma with Comedonecrosis: A Case Report

ABSTRACT

Adnexal clear cell carcinoma with comedonecrosis (ACCCC) is a very rare malignancy of the skin with an aggressive clinical course and a predilection for the scalp. This is the first reported case of ACCCC in Korea. A 79-year-old male presented with left abdominal masses that proved to be two subcutaneous nodules. The tumors histologically consisted of epithelial nests that showed a distinctive zonal arrangement. The centrally located clear cell areas with comedonecroses were merged with the peripheral squamoid cells, often exhibiting retraction artifacts and an infiltrating border. Nuclear pleomorphism and frequent mitoses were prominent. The clear cells were immunopositive for carcinoembryonic antigen and epithelial membrane antigen. We report here on a case of ACCCC involving the abdominal skin, and this tumor should be distinguished from the more indolent squamous cell and tricholemmal carcinomas.