Subclinical dilatation of dermal sweat ducts

1,323 biopsied skin specimens were retrospectively investigated. Dilatation of dermal sweat ducts was observed in 18 specimens (1.36%). They included 7 specimens of malignant and benign neoplasms or nevi, 5 of fibrosis and 6 of various inflammations. The face was the favored site, but it was also seen in other areas. Ten out of 18 specimens were taken in the summer. It was speculated that the massive secretion of sweat and the compression of sweat ducts by several tissue components in the dermis played an important role for the dilatation of the sweat ducts.