片側小脳萎縮を呈した毛様細胞性星細胞腫の1例

A case of pilocystic astrocytoma with cerebellar hemiatrophy

毛様細胞性星細胞腫（pilocytic astrocytoma）は小脳に発生することが多いが，小脳萎縮は伴わないとされている^1）。今回我々は，片側小脳の萎縮を伴う毛様細胞性星細胞腫の1例を経験したので文献的考察とともに報告する。

We report a case of pilocytic astrocytoma located in the cerebellar hemispheres in a man in his 20s. In this case, pilocytic astrocytoma was observed with unilateral cerebellar atrophy. Unilateral cerebellar atrophy is characteristic of gangliogliomas under the tentrium, but can also be seen in other tumors, including pilocytic astrocytoma. Even in the presence of unilateral cerebellar atrophy, a pilocytic astrocytoma should be considered in the differential diagnosis if imaging suggests a pilocytic astrocytoma.