Abstract

A case of eccrine porocarcinoma is reported. A 78-year-old man had had a red tumor on his right preauricular region during the last 2 months, which was 25×15mm in diameter and was covered with yellowish necrotic mass. Histopathologically, the tumor had a down-growth up to the deep dermis and it was composed of atypical cells which had the intracellular canaliculi in part. Cytoplasms of tumor cells showed PAS-positive and CEA-staining was positive in cytoplasms and intracellular canaliculi in part. EMA was positive in tumor cytoplasms of peripheral lesion. On electron micrograph, intracellular canaliculi had numerous microvilli in some tumor cells. These findings were compatible with eccrine porocarcinoma.
p53 protein was overexpressed in nuclei of almost all tumor cells and the PCNA labeling index was 80% in tumor nuclei, which was higher than SCC cases in the previous reports.