Fibrosarcoma of the meninges.

Meningeal fibrosarcomas are rare tumors. Only 41 cases have been reported in the literature to date. Primary central nervous system fibrosarcomas are very aggressive neoplasms and have a poor prognosis. Hence they need to be correctly diagnosed. This is a case of a 13-year old boy with intracranial space occupying lesion. The mass was completely removed and histological examination was characteristic of meningeal fibrosarcoma. The pathological diagnosis is usually made on routine light microscopic examination; however, occasionally these may be difficult to distinguish from other malignant neoplasms such as gliomas, meningiomas and metastases. The diagnosis of fibrosarcoma is based on the identification of a predominant herringbone architectural pattern, the overall uniformity of the spindle cell population, the prominent vimentin positivity, and the presence of pericellular reticulin fibre network. IHC helps to exclude other diagnoses.