SMALL-CELL SWEAT GLAND CARCINOMA IN CHILDHOOD

Sweat gland carcinomas are rare skin tumors that typically occur in ol der patients. The spectrum of their clinical and pathologic features i s broad, and many different types of sweat gland carcinomas have been described, ranging from fairly indolent to highly aggressive neoplasms . We present two cases of sweat gland carcinoma with a predominant sma ll cell morphology. Both tumors occurred in children. One lesion devel oped in an 8-year-old girl as an asymptomatic papule on her left forea rm, which ultimately was evaluated using biopsy because of rapid growt h and change in color. The other lesion occurred on the hand of a 12-y ear-old boy. Both tumors were pandermal and extended into fat. They we re composed of monotonous cuboidal cells with scant cytoplasm that for med tubules and grew in anastomosing cords and trabeculae. The tumor c ells were immunoreactive for cytokeratins but not for cytokeratin 20. Ultrastructural analysis (available in one case only) showed that the tumor cells lacked neurosecretory granules. This variant of sweat glan d carcinoma needs to be distinguished from other small cell neoplasms of the skin, especially Merkel cell carcinoma, its closest mimic.