A scaly lesion manifested on this 55-year-old man’s back several years ago. Over time, the lesion has grown, despite the application of several different OTC creams, including hydrocortisone and various antifungal creams. Previously asymptomatic, the lesion is now beginning to itch and occasionally bleed.
Additional history-taking reveals that for the first 10 years of his working life, the patient was a concrete finisher, working 12-hour shifts in the sun without a shirt, six days a week for months at a time. Aside from a 40-pack-year history of smoking, his health is “decent.”
The lesion is an 8 x 10–cm pink, scaly plaque with thready, well-defined scaly margins. Tiny focal erosions are seen in the peripheral leading edge. Closer inspection of the lesion’s center reveals multiple telangiectasias and a complete lack of hairs or hair follicles. Elsewhere on sun-exposed areas of the patient’s truncal skin, there are thousands of solar lentigines. Multiple small actinic keratoses are noted on his face as well.
What is the diagnosis?