Brachium Pontis Gliosarcoma With Well-Differentiated Cartilaginous Tissue: A Case Report.

Gliosarcoma (GS) belongs to World Health Organization grade IV neoplasm and displaying glial and mesenchymal differentiation. Only rare cases of GS have been reported in the brachium pontis and 4th ventricle region. Here, we report a rare case of GS located on brachium pontis region and extending into the 4th ventricle with well-differentiated cartilaginous metaplasia. A 28-year-old male patient experienced intermittent headache, vomiting, and gait disorders for 3 months. Magnetic resonance imaging (MRI) showed a heterogeneous ring-enhancement lesion with weak central enhancement in left brachium pontis and 4th ventricle region. Histology revealed the GS was constituted with glial and sarcomatous elements. After immunohistochemical analysis, a diagnosis of GS with cartilaginous differentiation was then made.Symptoms of GS, including headache, aphasia, hemiparesis, cognitive decline, and seizures, mainly determined by the location. The clinical manifestation and radiologic characteristic is not significantly different from that of glioblastoma. The grade of resection is the significant factor related to prognosis of GS, and the clinical effect of adjuvant radiotherapy and chemotherapy need further study. Reporting additional cases would be of great help in better understanding of this location and pathologic type of GS.