[Brain stem glioma induced by radiotherapy: report of a case].

A case of brain stem glioma following radiotherapy for brain tumor is presented. A 44-year-old female was admitted with chief complaints of gait disturbance and disturbed consciousness. She had received radiation therapy with 60Gy following resection of a right temporal astrocytoma 20 years before, but until admission this time follow up CT scan had shown no regrowth. On admission CT scan and MRI showed an enhanced mass (2 x 2.5cm) in the mid-brain. Tumor biopsy was performed using the subtemporal approach. The histological diagnosis showed a fibrillary astrocytoma grade III. The patient received postoperative synchronized chemotherapy but expired 8 months after admission. The growth of glioma appeared in the previous radiation field after a long latent period. This case should be considered not as a case of the regrowth of a tumor but as a case of a radiation induced tumor. Although 77 cases of gliomas following radiation for intracranial tumor have been reported, this case of radiation-induced brain stem glioma is extremely rare.