The relationship of sun exposure and solar elastosis to basal cell carcinoma.

The significance of sun exposure in the pathogenesis of basal cell carcinoma (BCC) was assessed. A total of 262 tumors were studied. Most of the tumors occurred in patients over 40 years of age, with a male to female ratio of 3:2. The majority of tumors were present on the head and neck, mostly on sites maximally exposed to sun. Solar elastosis of varying degrees was recorded in 93% of tumors, some of which occurred in relatively covered areas such as the scalp and trunk. Exposure to ultraviolet radiation thus represents a major factor in the pathogenesis of BCC. Surprisingly, 26% of tumors had mild elastosis, nearly half of which occurred on exposed sites such as the forehead, nose, and cheeks.