ECCRINE POROCARCINOMA WITH MELANOCYTE COLONIZATION

We describe a 74-year-old Japanese man with a pigmented eccrine poroca rcinoma (malignant eccrine poroma). The patient had a brown-black nodu le measuring 9x7mm on his leg. Microscopically, the tumour, which had invaded the reticular dermis, was composed of poroid cells with large and small intracytoplasmic lumina. The tumour cells showed cytological pleomorphism and frequent, often abnormal, mitotic figures. Many dend ritic melanocytes containing melanin were intermingled with the tumour cells. The poroid cells were diffusely positive for cytokeratin, whil e the dendritic cells containing melanin were positive for S-100 prote in and HMB-45. Ten months of follow-up revealed no recurrence or metas tasis of the tumour.