Malignant intracerebellar schwannoma.

The authors report an exceptional case of malignant cerebellar schwannoma in a 29-year-old woman, explored by computed tomography and angiography; a solid and vascular vermian tumor was removed at operation. The histological diagnosis of malignant schwannoma with epithelioid areas was confirmed by immunohistological staining (positive S-100 protein, Leu 7 and vimentin, negative glial fibrillary acid protein, cytokeratin, desmin and HMB45). The patient died 8 months after surgery for tumor recurrence. The literature review has shown 44 cases of schwannomas occurring in the cerebral hemispheres, 9 within the brain stem and 14 in the cerebellum. All but one reported cerebellar schwannomas were benign, with prevalence of young patients and vermian localization. The present case is the second reported malignant intracerebellar schwannoma.