Cutaneous carcinoma induced by radiotherapy: a report of 31 cases

Depilatory radiotherapy was used in the sixties as a treatment for ringworm in Tunisia. Subsequently some of these patients developed radio-induced carcinomas of the scalp. To present the epidemiological, clinical, pathological,therapeutic features and out come of radio-induced cutaneous carcinomas. We conducted a retrospective study performed in the dermatology department of the La Rabta hospital of Tunis over a 6- year-period recording all histologically confirmed carcinomas in patients irradiated in childhood for tinea capitis. Thirty one patients were included with 49 tumors: 47 basal cell carcinomas and 2 squamous cell carcinomas. The average latent period between the irradiation and the appearance of the carcinomas was of 35.7 years. The average age was 53 years. A male predominance was noted, with a sex ratioM/F of 6.75. Clinically, basal cell carcinomas were nodular in all cases. Surgery was indicated in 90% of cases. Cryosurgery and radiotherapy were used respectively in 1 and 2 patients. Our study shows that radio-induced cutaneous carcinomas are widely dominated by basal cell carcinoma. They arise, approximately, ten years earlier than carcinoma in patients with no history of scalp irradiation. However X-ray exposure does not seem to influence clinical or histological presentation, therapeutic modalities nor prognosis of these tumors. The prognosis of radioinduced cutaneous carcinomas was globally similar to that of other cutaneous carcinomas with same histological type and equivalent degree of invasion.