title: Malignant transformation of clival chordoma after gamma knife surgery - case report - .
abstract: A 54-year-old woman presented a midline clival tumor manifesting as right abducens palsy in May 1997. Magnetic resonance (MR) imaging revealed a midline clival tumor. She underwent surgery twice with the transsphenoidal approach and gamma knife surgery for residual tumor. The histological diagnosis was chordoma. MR imaging revealed that the tumor had extended to the right cerebellopontine angle, with spinal seeding in February 2002. She underwent partial removal of the right cerebellopontine angle tumor. The histological diagnosis was chordoma with slight nuclear atypism. She died 5 years and 5 months after the first gamma knife surgery. Autopsy revealed multiple areas of spinal seeding. Histological examination confirmed malignant transformation with unique epithelial characteristics, possibly caused by gamma knife surgery.
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, University of Toyama, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Tsuboi
authors.forename: Nakamasa
authors.initials: N
authors.lastname: Hayashi
authors.forename: Masanori
authors.initials: M
authors.lastname: Kurimoto
authors.forename: Shoichi
authors.initials: S
authors.lastname: Nagai
authors.forename: Masakiyo
authors.initials: M
authors.lastname: Sasahara
authors.forename: Shunro
authors.initials: S
authors.lastname: Endo
mesh_terms: D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D002817:Chordoma / Q000473:pathology* / Q000601:surgery; D003388:Cranial Fossa, Posterior / Q000473:pathology / Q000601:surgery; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D008875:Middle Aged; D009366:Neoplasm Seeding; D016634:Radiosurgery; D019292:Skull Base Neoplasms / Q000473:pathology* / Q000601:surgery; D013116:Spinal Cord / Q000473:pathology; D013120:Spinal Cord Neoplasms / Q000556:secondary*