Radiation-induced leiomyosarcoma of the dura mater: a case report

A 31-year-old man underwent total resection for a fibrillary astrocytoma in the right frontal lobe followed by 6 MV x-ray radiotherapy. The portal field size was a square of 8 cm x 7 cm, and the total dose of irradiation was 50 Gy, with single fractions of 2 Gy. For the next 6.5 years there was no recurrence of the astrocytoma. At 38 years of age, the patient noticed a subcutaneous mass in the scar of the previous operation and developed generalized convulsive seizures. MRI revealed a dural tumor within the previous radiation field, and the tumor was partially removed. Histologically, it was diagnosed as a leiomyosarcoma. This dural sarcoma satisfies the widely used criteria for definition of radiation-induced malignancies first described by Cahan et al. Both the clinical features and the possible histogenesis of this secondary tumor are briefly discussed. (author)