title: Sarcomatous transformation of clival chordoma after charged-particle radiotherapy. Report of two cases.
abstract: Skull base chordomas containing a sarcomatous component are extremely rare. Here the authors report two new cases in which a recurrent tumor with a sarcomatous component appeared after the patient had undergone charged-particle radiotherapy. Histological examinations performed in Case 1 revealed some retention of epithelial features in the sarcomatous component, whereas no such regions were observed in Case 2. Both patients had rapidly deteriorating clinical courses and died within 6 months after diagnosis of the recurrent tumor. The authors discuss the significance of the histological subtypes of these tumors for long-term prognosis and their pathogenetic mechanisms in relation to radiotherapy. Although these sarcomatous transformations are rare in conventional chordomas, a careful histological examination and thorough follow-up imaging studies are crucial when treating patients with such lesions.
authors.affiliation: Department of Neurosurgery, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hara
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Kawahara
authors.forename: Koji
authors.initials: K
authors.lastname: Tsuboi
authors.forename: Junji
authors.initials: J
authors.lastname: Shibahara
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ushiku
authors.forename: Takaaki
authors.initials: T
authors.lastname: Kirino
mesh_terms: D000328:Adult; D002471:Cell Transformation, Neoplastic; D002817:Chordoma / Q000473:pathology* / Q000532:radiotherapy*; D003388:Cranial Fossa, Posterior; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D008875:Middle Aged; D012509:Sarcoma / Q000473:pathology* / Q000628:therapy; D019292:Skull Base Neoplasms / Q000473:pathology* / Q000532:radiotherapy*