Trichoid basal cell carcinoma found in a dilated pore on the nose.

A pore of Winer is a common, benign epidermal appendageal tumor arising from a hair follicle. We present a case where routine removal of a pore of Winer revealed the presence of a trichoid basal cell carcinoma. We describe the history of these lesions, discuss clinical and histologic differential diagnoses, and propose an explanation for the presence of these tumor cells. No prior report of basal cell carcinoma within a pore of Winer has been documented in the literature.