We have observed hyperplastic epidermal lesions in sun-damaged skin on the backs of the hands, wrists, and forearms that, in some examples, contain foci of invasive squamous cell carcinoma. Atypia in these lesions is focal or absent. Because of their bland histology, physicians are likely to interpret small or superficial biopsies as indicating a benign lesion. However, careful clinical correlation and follow-up are recommended, as residual tissue may contain invasive carcinoma or its precursor.