title: [Medulloblastoma presenting as an extra-axial tumor in the cerebellopontine angle].
abstract: Differences in the imaging characteristic of adult medulloblastomas have been reported, including involvement of lateral cerebellar hemispheres with an extra-axial appearance. We present a case report of this rare circumstance: a 40 year old man presented with a 3 weeks history of headache, morning vomiting and left hearing difficulties. Magnetic resonance imaging revealed a left cerebellopontine angle (CPA) tumor, like a well circumscribed homogeneously enhancing mass. Through a left suboccipital craniectomy the tumor was totally removed. It presented as a cerebellopontine angle tumor, like a meningioma, and not as an intra-axial tumor. Histological analysis revealed that the tumor was composed of densely packed with highly proliferative cells that produce a dense intercellular reticulin fiber network. Inmunohistochemical analysis showed positive expression to synaptophysin, specific neuronal enolase and cromogranin. Histological diagnosis was crucial to define it as a desmoplastic medulloblastoma the present case and to perform postoperative adjuvant therapy. Neurosurgeons should be aware of the possibility that a CPA tumor is of intraaxial origin, because this increase the variability on pathological diagnosis.
authors.affiliation: Servicios de Neurocirugía. Hospital Universitario Puerta del Mar. Cádiz.
authors.forename: J L
authors.initials: JL
authors.lastname: Gil-Salú
authors.forename: F
authors.initials: F
authors.lastname: Rodríguez-Peña
authors.forename: M
authors.initials: M
authors.lastname: López-Escobar
authors.forename: M J
authors.initials: MJ
authors.lastname: Palomo
mesh_terms: D000328:Adult; D002528:Cerebellar Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D002530:Cerebellopontine Angle / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008527:Medulloblastoma / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D013125:Spinal Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000556:secondary; D014057:Tomography, X-Ray Computed