Well-differentiated squamous cell carcinoma of the eyelid arising during a 20-year period.

An 81-year-old man had a keratotic eyelid lesions for 20 years. He eventually sought treatment by ophthalmic plastic surgery. Clinically, the lesion resembled a keratoacanthoma. Findings from histologic examination of the excision biopsy specimen showed a squamous cell carcinoma. The lesion was completely excised. This case demonstrates the difficulty in making a correct clinical diagnosis of a keratotic eyelid lesion. Performing a histologic examination of nonregressed keratotic lesions is essential to exclude a squamous cell carcinoma.