Lichen planus is not considered to be one of the precancerous dermatoses.1,2Therefore, a case of hypertrophic lichen planus with epidermoid carcinoma developing within the plaque of lichen planus is considered worthy of a report. Two previous cases have been reported which are remarkably similar to the one presented here.3,4 Report of a Case A 78-year-old white male retired ship steward presented with skin lesions of 15 years' duration. The lesions involved the anterolateral aspects of both legs. They had started as small pruritic papules which gradually spread and thickened to form large plaques. Three weeks before the patient was seen, two small granulomatous lesions had developed on the right leg within the plaque of lichen planus. A complete history, physical examination, and laboratory studies including blood cell count, urinalysis, serologic tests for syphilis, liver-function studies, chest x-ray and ECG were noncontributory except for the following