CASE
A 58-year-old man presented to dermatology for evaluation of an asymptomatic lesion that had been present for the past 3 years. The lesion started out small but had continued to grow slowly and steadily despite the application of a number of OTC products, including tar-containing psoriasis cream, 1% hydrocortisone cream, and a variety of antifungal creams. The patient, who had worked outdoors most of his adult life, admitted to a 40-year history of smoking but claimed to be in good health otherwise. He had had a number of skin cancers removed over the years, all of which, he claimed, were melanomas that did not require additional surgery or follow-up.
On examination, the patient's intensely sun-damaged skin stood out, manifesting with a weathered effect, poikilodermatous changes, large numbers of solar lentigines, numerous minor actinic keratoses, and telangiectasias (mostly on the face). His sun-exposed skin had a leathery texture on palpation. The lesion in question, located on his left volar forearm, was a 638-cm pink polygonal plaque with focal areas of minor erosions (Figure 1). The surface of the lesion was covered with a light, easily removable scale. There were no signs of other skin diseases on his elbows, knees, or scalp. A shave biopsy was performed.
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