Granular Cell Astrocytoma of the Cerebellum

Abstract

Granular cell astrocytomas are an uncommon morphologic variant of infiltrating gliomas characterized by relatively large tumor cells with granular cytoplasm occupying variable proportions of the tumor. These tumors are thought to be more aggressive than similar tumors with no granular cell component. The tumor occurred in a 9-year-old girl who was immunocompromised owing to liver transplantation. Histologically, the tumor corresponded to World Health Organization grade II. It extensively infiltrated the cerebellum and was composed, predominantly, of large cells with eosinophilic granular cytoplasm. These cells coexpressed glial fibrillary acidic protein and CD68. Of the 49 cases of granular cell astrocytomas reported to date, none have involved the cerebellum. The tumor described herein represents the first case of cerebellar granular cell astrocytoma. Pathologic features and diagnostic pitfalls are explored.