A dermal duct tumor occurred on the left leg of a 66-year-old man. The lesion first occurred as a solitary lobulated tumor of approximately 20 years' duration. This apparently brings the total number of recorded cases to 12. It is believed to be a benign tumor of the intradermal portion of the eccrine sweat duct and is distinctive and diagnostic histologically. The spectrum of benign tumors of the eccrine sweat duct epithelium includes hidroacanthoma simplex or intraepidermal eccrine poroma, eccrine poroma, and dermal duct tumor.
Apisarnthanarax P, Mullins JF. Dermal Duct Tumor. Arch Dermatol. 1975;111(9):1171-1173. doi:10.1001/archderm.1975.01630210087011