Epidermoid cyst with sweat ducts on the torso.

We report a case of an epidermoid cyst arising on the upper chest that had a remarkable histologic pattern composed of structures resembling eccrine ducts in the horny layer and an acrosyringium. The expression of carcinoembryonic antigen (CEA) was also demonstrated immunohistochemically within these ductal structures. Eccrine ducts have been reported recently, in epidermoid cysts located in the palmoplantar region. The cyst described here suggests that epidermoid cysts derived from eccrine ducts may also appear on the torso.