Sunlight (actinic) keratosis: an update

摘要

There is considerable controversy regarding the nature of sunlight (solar/actinic) keratosis. One view is that sunlight keratosis is a premalignant condition [1-6]; another view is that ab initio it is a form of superficial squamous cell carcinoma (SCC) [7-9]. Sunlight keratosis results from abnormal proliferation of keratinocytes of sun-exposed skin. Common sites of occurrence are neck, hands, arms and head including the vermilion border of the lips, most frequently the lower lip [10, 11]. Sunlight keratotic lesions are dry, skin-coloured or brownish, rough macules or papules [1,4], The term sunlight keratosis refers only to the appearance of the lesion and to its aetiology, but not to its pathobiological behaviour or histopathological features.