Metastatic solitary fibrous tumor of the meninges. Case report.

Solitary fibrous tumor (SFT) is a unique tumor composed of interstitial dendritic cells that was first described in the thorax and subsequently reported in diverse organs. Extrathoracic SFTs are predominantly benign but rare malignant cases have been documented. In the nervous system, SFT has been described as a meningeal lesion although all 14 previously reported cases were benign. The authors report the first case of a meningeal SFT occurring in a 55-year-old woman. The tumor first presented as a meningeal lesion that after three recurrences over a 10-year period metastasized to the soft tissues and lungs. The potentially malignant nature of cranial SFTs, especially those with atypical histological features and high mitotic counts, should be recognized.