Basal cell carcinoma in a girl after cobalt irradiation to the cranium for acute lymphoblastic leukemia: case report and literature review.

A 12-year-old girl had a lesion located on the upper part of the scalp that was clinically interpreted as a melanocytic nevus and corresponded histologically to a basal cell carcinoma. At age 2 years she had been diagnosed as having acute lymphoblastic leukemia L1, for which she was treated with systemic chemotherapy. She also received telecobalt therapy to the whole cranium for prophylaxis of meningeal leukosis. Having rejected other possible causes that can favor the appearance of basal cell carcinoma during childhood (basal cell nevus syndrome, nevus sebaceus, albinism, etc.), we believe that this case should be added to the five previously reported in the literature as basal cell carcinoma developing at an early age in cranial radiation portals with megavoltage radiotherapy. We draw attention to the need to explore radiated areas of skin as part of the long-term follow-up of these patients, and to the advisability of obtaining a biopsy from any persistent lesion in these areas.