title: Unstable pathological fracture of the odontoid process caused by Langerhans cell histiocytosis.
abstract: METHODS
  A case report and literature review.
  
  
  OBJECTIVE
  To illustrate the spontaneous resolution of unstable pathological fracture of the odontoid process of the C2 caused by Langerhans cell histiocytosis (LCH) in early childhood.
  
  
  BACKGROUND
  The involvement of atlantoaxial LCH is very rare and its treatment is unfamiliar to surgeons. Therefore, the management of pediatric LCH of the odontoid process and the C2 body is challenging and must be adapted according to the patient's needs; it could range from observation to surgical intervention.
  
  
  METHODS
  A case of pathological fracture of the odontoid process with torticollis diagnosed with LCH of the odontoid process and C2 body and involving right femur in early childhood is presented. A histopathological study showed LCH. The patient underwent brace immobilization and systemic chemotherapy.
  
  
  RESULTS
  The patient showed successful bony remodeling without LCH recurrence on CT. The neck pain was resolved, and there was no limitation in neck movement.
  
  
  CONCLUSIONS
  Immobilization and systemic chemotherapy with close observation are adequate for the management of patients despite the unstable pathological fracture of the odontoid process.
authors.affiliation: Department of Orthopaedic Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea. kyh@catholic.ac.kr
authors.forename: Kee-Yong
authors.initials: KY
authors.lastname: Ha
authors.forename: Il-Nam
authors.initials: IN
authors.lastname: Son
authors.forename: Young-Hoon
authors.initials: YH
authors.lastname: Kim
authors.forename: Hyun-Ho
authors.initials: HH
authors.lastname: Yoo
mesh_terms: D002648:Child; D006646:Histiocytosis, Langerhans-Cell / Q000150:complications / Q000473:pathology*; D006801:Humans; D008297:Male; D009809:Odontoid Process / Q000293:injuries* / Q000473:pathology*; D016103:Spinal Fractures / Q000209:etiology / Q000473:pathology*