Papillary eccrine adenoma. A case report with immunohistochemical examination.

The case of a 52-year-old woman with papillary eccrine adenoma is reported. The lesion presented clinically as a slowly growing nodule on the dorsum of the left foot. Histopathologically, the tumor was composed of multiple, dilated tubular structures lined by two or more layers of epithelial cells. The inner cell layer formed intraluminal papillary projections in some of the tubules. Most of the lumina were filled by eosinophilic granular material. Immunohistochemical examinations that use the avidin-biotin method showed immunoreactivity to S-100 protein, carcinoembryonic antigen, and epithelial membrane antigen. These findings support the hypothesis that papillary eccrine adenoma differentiate toward the secretory epithelium of sweat glands.