Glioneurofibroma: renaming the pediatric "gliofibroma": a neoplasm composed of Schwann cells and astrocytes.

Three children had central nervous system tumors with histologic and ultrastructural features corresponding to those of tumors previously described as "gliofibromas." These features, which include a composite appearance with glial and mesenchymal elements, with glial fibrillary acidic protein (GFAP)-containing and GFAP-immunonegative cells, diffuse S-100 immunoreactivity, and basal lamina wrapping processes of both cell types, suggest that the "mesenchymal" cells are Schwann cells, not fibroblasts. We therefore propose to rename this entity "glioneurofibroma." The clinical behavior of these lesions is uncertain but is more often indolent or benign.