Congenital supratentorial and infratentorial peripheral neurogenic tumor: a clinical, ultrastructural, and immunohistochemical study.

Congenital neoplasms of the central nervous system are extremely rare, although they have been well documented since the earliest reports from the mid-19th century. Medulloblastoma, other primitive neuroectodermal tumors, and various types of gliomas have comprised the majority of cases. This report describes a highly unusual infratentorial and supratentorial tumor presenting as a scalp mass in a neonate who experienced in utero distress. The supratentorial mass extended through a defect in the skull to the parietooccipital lobe, and the infratentorial aspect involved the 9th and 10th cranial nerves in the region of the cerebellopontine angle. A complex spindle cell neoplasm incorporating peripheral nerve sheath and vascular characteristics was further characterized by electron microscopy and immunohistochemistry. Based upon these studies, the tumor was interpreted as a congenital schwannoma with divergent vascular differentiation. The child has been tumor-free for approximately 2 years after the initial operative procedure.