Multiple basal cell carcinoma developing two years after 60Co irradiation.

A 66-year-old Japanese man developed multiple basal cell carcinoma 2 years after receiving 60Co irradiation for oropharyngeal tumors. All of the tumors were located within the radiation fields where the skin was atrophied and telangiectatic. In the present case, the total dose (112 Gy) of 60Co radiation received by the patient had been large and the latent period was much shorter than in previously reported cases. It is suggested that the reasons for the short latency in our case were 1) the total radiation dose and 2) the fact that the area irradiated was a frequently sun-exposed area.