title: Ectomesenchymal hamartoma (benign "ectomesenchymoma") of the VIIIth nerve: case report.
abstract: We report a previously undescribed hamartoma of the VIIIth nerve, consisting of adipose tissue, Schwann cells associated with myelinated nerve fibers, well-differentiated smooth and striated muscle fibers, and rare ganglion cells. The tumor was found in a 35-year-old Caucasian female who presented with right-sided hearing loss. The mass, which we designate an "ectomesenchymal" hamartoma, most likely developed from pluripotent neural crest cells ("ectomesenchyme"), which are capable of differentiating into a variety of neuroectodermal and mesenchymal cell types. The development of the neural crest, the concept of "ectomesenchyme," and the histogenesis of this tumor are reviewed.
authors.affiliation: Division of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Apostolides
authors.forename: R F
authors.initials: RF
authors.lastname: Spetzler
authors.forename: P C
authors.initials: PC
authors.lastname: Johnson
mesh_terms: D000328:Adult; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D003390:Cranial Nerve Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008637:Mesenchymoma / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D000159:Vestibulocochlear Nerve / Q000473:pathology / Q000601:surgery; D000160:Vestibulocochlear Nerve Diseases / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*