Eruptive clear cell hamartoma of sweat duct.

A histologically unique condition of the sweat duct was found in a miliaria-like papular eruption on the extensor surfaces of extremities of a 41-year-old female patient. The hypertrophic epithelium of the sweat duct wall consisted of extensively vacuolated clear cells. There was mild hyperkeratosis around the sweat duct orifice. The eccrine gland cells showed only partial vacuolization. Since this condition is not related to any of the other known benign changes of the eccrine duct, we report it with a presumptive descriptive diagnosis of eruptive clear cell hamartoma of sweat duct.