A case of clear cell eccrine porocarcinoma

Eccrine porocarcinoma (EP) is a rare malignant tumor arising from the intraepidermal eccrine duct. The tumor cells frequently contain glycogen, but prominent clear cell changes in EP are rarely reported. A 78-year-old woman presented with a slightly pruritic, erythematous, verrucous plaque on her left thigh. Histopathological examination revealed intraepidermal tumor cell nests composed of small basaloid cells and duct-like structures lined by periodic acid-Schiff (PAS)-positive cuticles. Besides the typical findings of EP, clear cell changes were predominantly observed in the tumor cell aggregations. Herein we report a case of the clear cell variant of EP rarely reported in previous literature.