Granular cell tumors in the central nervous system: a report on eight cases and a literature review.

OBJECTIVE: Granular cell tumors (GCTs) in the central nervous system (CNS) are extremely rare. We report here a series of eight GCTs at various locations in the CNS and provide a full review of the published literature.

METHODS: Eight patients with pathologically confirmed GCT in the CNS were retrospectively reviewed. The patients were followed up via telephone interview or an outpatient department.

RESULTS: Five patients were female, and three were male. Of the eight tumors, three were located at the sellar region, two were located in the spinal canal, one was located at the cerebral hemisphere, one was parasellar-nasal communicating, and one was combined with an enterogenous cyst at the ventral aspect of the medulla oblongata. Six patients were symptomatic, and two patients were found incidentally. Most GCTs tended to be homogeneous and well defined on radiological images. The parasellar-nasal communicating GCT showed destruction of the skull base and an evident cystic component in the sphenoid sinus. The various GCTs had similar histological features, and they tended to be histologically benign. Most tumors did not recur after the operation. After subtotal resection, one residual spinal GCT regrew during the follow-up period. The patient with the parasellar-nasal communicating GCT developed progressive visual loss in the right eye after the operation; and she received adjuvant radiation therapy.

CONCLUSION: GCTs at different locations in the CNS can have significantly different clinical features and should be considered distinct entities. Except for the granular cell astrocytoma (GCA), most GCTs in the CNS tended to be benign. Malignant GCTs are rare and difficult to treat.