A case of digital papillary adenocarcinoma

We report a case of 50-year-old man who presented a digital tumor that had been gradually enlarging for 1 year. On examination, he had an ulcerated crusty nodule of 2 cm in diameter on his left thumb. Histopathologically, an excisional biopsy specimen showed infiltration of tumor cells with mitoses in the dermis and subcutis forming ductal structures. Immunohistochemically, these tumor cells were positive for AE1/AE3, EMA, and CK14, and focally positive for CEA, but were negative for estrogen receptor, progesterone receptor, and GCDFP15, with an MIB-1 index of 30%. He was diagnosed as having digital papillary adenocarcinoma and extended resection was carried out. Digital papillary adenocarcinoma is a malignant sweat gland tumor that frequently recurs and metastasizes. We described a clinically and histopathologically typical case of digital papillary adenocarcinoma.