Squamous cell carcinoma. Occurrence in mycosis fungoides treated with psoralens plus long-wave ultraviolet radiation.

In two patients with mycosis fungoides, a squamous cell carcinoma developed during therapy with psoralens plus long-wave ultraviolet radiation (PUVA). In both patients the carcinoma developed on areas not usually exposed to sunlight. Before receiving PUVA therapy one patient had been treated with topically applied thiotepa and x-ray irradiation, while in the other patient PUVA was the only treatment received except for topical corticosteroids. The carcinomas developed after a total UVA dose of 2,042 and 1,296 joules/sq cm, respectively.