A case of primary cutaneous mucinous carcinoma with neuroendocrine differentiation

Primary cutaneous mucinous carcinoma is a rare malignant tumor that originates from the deepest portion of the eccrine sweat duct. Common sites of involvement are the face and scalp. Biopsy shows dermal epithelial cell islands embedded in mucin pools separated by fibrous septae. It is difficult to differentiate this tumor histologically from metastatic adenocarcinoma. Recurrence after excision is common but metastases are rare. We report a primary cutaneous mucinous carcinoma with neuroendocrine differentiation on the right cheek of a 63-year-old man.