Seborrheic keratosis-like changes in epidermal inclusion cyst: An unusual feature in a usual entity

Abstract

A 58-year-old male presented with an asymptomatic, slowly growing, cystic and mobile swelling on the left leg calf of 6 months duration. Fine-needle aspiration cytology was suggestive of epidermal inclusion cyst. Histopathological examination revealed seborrheic keratosis-like changes in the cyst wall comprising of marked acanthosis, papillomatosis, pseudohorn cysts, squamous eddies, and clumps of keratohyalin granules. This is a very rare variant of epidermal inclusion cyst, possibly induced by infection with human papillomavirus.