title: Malignant teratoma in Klippel-Feil syndrome: a case report and review of the literature.
abstract: BACKGROUND
  Klippel-Feil syndrome is characterized by a congenital fusion of cervical vertebrae. Intracranial teratomas are nongerminomatous germ cell tumors and they account for 0.3 to 0.9% of all intracranial tumors. Teratomas with malignant transformation refer to lesions which give rise to malignant cancer of somatic type. The association between tumors of dermoid origin and Klippel-Feil malformation is extremely rare. Only 23 other cases have so far been reported, and only one case of dermoid tumor with areas of dedifferentiation on squamous cell carcinoma has been described.
  
  
  METHODS
  We report the case of a 72-year-old white man with a 2-year history of gait and balance disturbances. A brain magnetic resonance imaging revealed a fourth ventricle neoplastic process with infiltrative features. He was operated through a suboccipital craniectomy with a C1 laminotomy and bilateral vertebral artery transposition. At 6-months follow-up, magnetic resonance imaging showed an early regrowth of the fourth ventricle tumor, with the same radiological features.
  
  
  CONCLUSIONS
  Patients with Klippel-Feil malformation could develop posterior fossa dermoid tumors. The malignant potential of such tumors must be considered and surgery is recommended. Particular attention must be focused on the histopathological analysis in order to identify possible foci of malignant transformation.
authors.affiliation: Department of Neurosurgery - AOOR Papardo-Piemonte, Contrada Papardo, 98158, Messina, Italy. aleadorno@yahoo.it.
authors.forename: A
authors.initials: A
authors.lastname: Adorno
authors.affiliation: Department of Neurosurgery - AOU Policlinico "G.Martino", Via Consolare Valeria, 98125, Messina, Italy. calafaci@unime.it.
authors.forename: C
authors.initials: C
authors.lastname: Alafaci
authors.affiliation: Department of Neurosurgery - AOOR Papardo-Piemonte, Contrada Papardo, 98158, Messina, Italy. fra.sanfilippo@hotmail.com.
authors.forename: F
authors.initials: F
authors.lastname: Sanfilippo
authors.affiliation: Department of Neurosurgery - AOOR Papardo-Piemonte, Contrada Papardo, 98158, Messina, Italy. danielecaf@libero.it.
authors.forename: D
authors.initials: D
authors.lastname: Cafarella
authors.affiliation: Department of Neurosurgery - AOOR Papardo-Piemonte, Contrada Papardo, 98158, Messina, Italy. monica.scordino@libero.it.
authors.forename: M
authors.initials: M
authors.lastname: Scordino
authors.affiliation: Department of Neuroradiology, University of Messina, Messina, Italy. fgranata@unime.it.
authors.forename: F
authors.initials: F
authors.lastname: Granata
authors.affiliation: Department of Neurosurgery - BIONEC, University of Palermo, Palermo, Italy. giovanni.grasso@unipa.it.
authors.forename: G
authors.initials: G
authors.lastname: Grasso
authors.affiliation: Department of Neurosurgery - AOOR Papardo-Piemonte, Contrada Papardo, 98158, Messina, Italy. fsalp@unime.it.
authors.forename: F M
authors.initials: FM
authors.lastname: Salpietro
mesh_terms: D000368:Aged; D002574:Cervical Vertebrae / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000473:pathology*; D003388:Cranial Fossa, Posterior / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D003884:Dermoid Cyst / Q000473:pathology; D020235:Gait Apraxia / Q000209:etiology; D006801:Humans; D007714:Klippel-Feil Syndrome / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D013724:Teratoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome