髄腔内播種所見を伴わない頚髄転移性乏突起膠腫の1例

A Case of Intramedullary Cervical Metastasis from Cerebellar Anaplastic Oligodendroglioma without Typical MR Appearance for CSF Dissemination

Ⅰ．はじめに

　悪性神経膠腫での髄腔内播種は，原発巣の悪化に伴う腫瘍伸展の最終段階で多くみられ，その終末期においてはときに経験する病態である．その際は，大部分の症例において脳室壁や脳・脊髄くも膜下腔の異常造影所見，leptomeningeal enhancementを伴うことが多く，容易に診断可能となる^1,3,8)．

　今回われわれは，小脳の退形成性乏突起膠腫の術後に，原発巣の再発兆候や脳・脊髄くも膜下腔のleptomeningeal enhancementを伴わず，頚髄レベルへの髄内転移巣を形成した比較的稀な症例を経験したので，文献的考察を加えて報告する．

　We report a case of intramedullary cervical metastasis from cerebellar anaplastic oligodendroglioma without any MR appearance for CSF dissemination or recurrence in the primary tumor site. The case was a 73-year-old female who underwent tumor resection for cerebellar anaplastic oligodendroglioma following irradiation and TMZ chemotherapy. One year and a half later, a small nodular lesion developed at the temporal lobe. While treatment with TMZ was restarted during the course, another intramedullary cervical lesion produced additionally without any CSF dissemination or recurrence at the primary site. The histological examination obtained in spinal surgery revealed evidence of similar features consistent with a previous cerebellar tumor with anaplastic oligodendroglioma. Although CSF dissemination by malignant glioma with leptomeningeal enhancement is relatively well recognized at their terminal stage, cases with intramedullary cervical metastasis without any leptomeningeal enhancement have only been rarely described. We discussed the mechanisms of intramedullary cervical metastasis from intracranial malignant glioma.