Complex cerebral tumor with evidence of neuronal, glial and Schwann cell differentiation: a histologic, immunocytochemical and ultrastructural study.

An unusual cerebral tumor is reported in a ten-month-old boy. The tumor was large (10 cm x 6 cm), firm and included several cysts. Light and electron microscopy showed a striking cellular pleomorphism. Typical neurosecretory ganglion cells were observed, always surrounded by Schwann cells. Amyelinic neurites, clusters of Schwann cells, fibroblasts and numerous foci of GFA positive astrocytes composed the tumor. These features were compared with the rare previous electron microscopic reports of cerebral neuronal tumor of the central nervous system. A dysembryoplastic origin from the neural plate was retained to explain the growth of such a complex tumor.