髄膜腫再発が疑われた膠芽腫の1例

Glioblastoma Mimicking Meningioma Recurrence: A Case Report

髄膜腫と神経膠腫が同部位に発生することは非常に稀である。今回われわれは，髄膜腫摘出後に再発が疑われ腫瘍摘出を行ったところ膠芽腫であった1例を経験した。症例は67歳女性，左前頭部髄膜腫に対して摘出術が行われ，fibrous meningiomaと診断された。術後2年11カ月目に摘出部に腫瘍を認め再発を疑い摘出術を行った。悪性髄膜腫が疑われたが，病理組織診断は膠芽腫であった。IDHはwild type，TERT promoterのmutationを認め，de novoに発生した膠芽腫と診断した。

Abstract

Meningioma and glioma represent two common primary intracranial tumors. However, the coexistence of these two lesions in the same patient at the same location is rare. Here, we present a case of a fibroblastic meningioma with a secondary glioblastoma occurring at the same location. A 67-year-old woman underwent surgery for a left frontal parasagittal meningioma, and the tumor was subtotally removed. Two years and 11 months after the surgery, the patient had a tumor at the same location with invasion into the adjacent brain, suggesting recurrent meningioma with malignant transformation. The resected tumor was confirmed histopathologically as a glioblastoma. Genetic analysis revealed that the isocitrate dehydrogenase 1 and 2 genes were wild type, and the TERT promoter mutation was detected. The gene analysis suggests that the tumor was a de novo glioblastoma, not a secondary glioblastoma from a lower-grade glioma.

(Received April 9, 2020; Accepted May 27, 2020; Published October 1, 2020)