Porokeratotic eccrine ostial and dermal duct nevus: a case report and review of the literature.

Hamartomas with eccrine differentiation are quite rare. There are 5 accepted classifications: eccrine nevus, eccrine-centered nevus, eccrine angiomatous hamartoma, eccrine syringofibroadenoma, and porokeratotic eccrine ostial and dermal duct nevus. The latter, PEODDN, typically presents as congenital keratotic papules and plaques located on the distal extremities. We report a classic case of PEODDN that was localized to the left hand since early childhood. The literature on this rare benign tumor is also reviewed.