Meningioangiomatosis not associated with von Recklinghausen's disease--case report.

A 7-year-old girl with meningioangiomatosis not associated with von Recklinghausen's disease is described. The radiological findings were similar to meningioma, but intraoperatively, a thin septum was found between the mass and the dura mater. Microscopically, there was significant proliferation of fibroblastic spindle-shaped cells and collagenous fibers in the subarachnoid space. Proliferated cells had penetrated into the cortical tissue along the irregularly branched blood vessels. Immunohistochemically, these penetrating perivascular cells were negative for glial fibrillary acidic protein and S-100 protein, and positive for vimentin staining. These findings suggest that the histogenesis of the spindle-shaped cells is most probably meningothelial.