title: A case of malignant peripheral nerve sheath tumor of the hypoglossal nerve after stereotactic radiosurgery treatment.
abstract: Objectives Hypoglossal schwannomas are rare. Surgical resection has been the standard treatment modality. Radiosurgery has been increasingly used for treatment. Radiation-associated secondary malignancy/malignant transformation has not been documented in the literature for the treatment of nonvestibular schwannomas. Setting The patient was a 52-year-old man with an enlarging high cervical/skull base lesion 8.5 years after CyberKnife treatment of a presumed vagal schwannoma. A decision was made for surgical resection, and the tumor was found to originate from the hypoglossal nerve intraoperatively. Final pathology diagnosis was malignant peripheral nerve sheath tumor. Results Patient had a gross total resection. Three months after resection, he received fractionated radiation of 50 Gy in 25 fractions and a boost gamma knife radiosurgery of 10 Gy to the 50% isodose surface. He remained tumor free on repeat magnetic resonance imaging 9 months after the resection. Conclusion Although extremely rare, radiation treatment of nonvestibular schwannomas can potentially cause malignant transformation.
authors.affiliation: Department of Neurosurgery, University of Washington, School of Medicine, Seattle, Washington, United States.
authors.forename: Tong
authors.initials: T
authors.lastname: Yang
authors.affiliation: Department of Pathology, University of Washington, School of Medicine, Seattle, Washington, United States.
authors.forename: Gordana
authors.initials: G
authors.lastname: Juric-Sekhar
authors.affiliation: Department of Pathology, University of Washington, School of Medicine, Seattle, Washington, United States.
authors.forename: Donald
authors.initials: D
authors.lastname: Born
authors.affiliation: Department of Neurosurgery, University of Washington, School of Medicine, Seattle, Washington, United States.
authors.forename: Laligam N
authors.initials: LN
authors.lastname: Sekhar
keywords: malignant peripheral nerve sheath tumor; nonvestibular schwannoma; radiation associated malignancy; stereotactic radiosurgery
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