頭蓋咽頭腫の放射線治療16年後に発生した傍側脳室Anaplastic Astrocytomaの1例

A Case of Paraventricular Anaplastic Astrocytoma Following Radiation Therapy for Craniopharyngioma

I．はじめに

　脳腫瘍の治療において放射線治療は手術と並んで重要な地位を確立しているが，一方，放射線治療後，比較的長期生存を果たしている症例の中に新たに放射線誘発脳腫瘍が発生することがあり注目されている．放射線誘発脳腫瘍としては肉腫，髄膜腫の頻度が高くこれらに比べると神経膠腫はまれである^7,12）．

　今回，頭蓋咽頭腫の手術および放射線治療後16年を経過して脳梁を中心とした傍側脳室部にanaplastic astrocytomaを発生した症例を経験したので，若干の文献的考察を加えて報告する．

A 20-year-old man received 60Gy of radiation ther-apy after partial removal of craniopharyngioma. The patient had been well and follow-up CT scans did not show any aggravation for 16 years. Since his activity gradually diminished, he underwent an MRI at the age of 36 which revealed an abnormal mass on the corpus collosum. The mass lesion progressively enlarged there-after, and was diagnosed as anaplastic astrocytoma by a stereotactic biopsy. He was treated with interferon, however, died at the age of 37. Review of literature dis-closed 19 other cases of glioma following radiation therapy for sellar/parasellar tumors. Characteristic fea-tures of these cases included, 1) lowness of age com-pared to common glioma cases, 2) tendency to be malignant, 3) tendency to occur in areas where signifi-cant doses of radiation had been received previously.