Skin cancer: comparison of aggressive potentials of sunlight-induced and x-ray-induced tumors.

Differences in clinical behavior between sunlight- and x-ray-induced skin cancer have been shown. The frequency of occurrence of multiple lesions is greater in those induced by x-ray than in the solar or nevoid type. Recurrence and major surgical sequelae appear to be greater with x-ray-induced lesions. The electron microscopic pictures of sunlight-induced and x-ray-induced basal cell carcinoma are different.