title: [Mastoid eosinophilic granuloma: a case report].
abstract: OBJECTIVE
  Langerhans cell histiocytosis is a proliferating cell disease that may take various forms characterised by bone, skin lymph nodes and visceral lesions. Eosinophilic granuloma is a localised form of histiocytosis X, or Langerhans' cells histiocytosis, a benign form with unknown aetiology. At the head and neck level, it is usually located on the temporal, and usually occur in association with multifocal disease; however, isolated lesions may occur in the mastoid bone alone.
  
  
  METHODS
  The author's present a case of a patient with unifocal eosinophilic granuloma limited to the mastoid treated in ENT and radiotherapy departments.
  
  
  RESULTS
  CT scan demonstrated an osteolytic lesion of the mastoid. The biopsy and immunohistochemical study confirmed the diagnosis. A surgery followed by a radiotherapy (20 Gy) have stabilised the situation. There is no recurrency after one year.
  
  
  CONCLUSIONS
  Unifocal eosinophilic granuloma of the temporal bone is a benign lesion of langerhans' cell histiocytosis. Its diagnosis is difficult when the disease remains isolated. Its treatment depend on its extension and its risks. The excellent prognosis does not dispense on regulary follow up.
authors.affiliation: CHU IBN SINA, Service ORL et Chirurgie Cervico-Faciale, Rabat, Maroc. ibtissam29@hotmail.com
authors.forename: A Filali
authors.initials: AF
authors.lastname: Adib
authors.forename: A
authors.initials: A
authors.lastname: Lazrak
authors.forename: M
authors.initials: M
authors.lastname: Boulaich
authors.forename: N
authors.initials: N
authors.lastname: Nazih
authors.forename: A
authors.initials: A
authors.lastname: Oujilal
authors.forename: M
authors.initials: M
authors.lastname: Kzadri
mesh_terms: D000293:Adolescent; D001706:Biopsy; D001847:Bone Diseases / Q000175:diagnosis*; D004803:Eosinophilic Granuloma / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008416:Mastoid / Q000473:pathology*; D010014:Osteolysis / Q000175:diagnosis; D013701:Temporal Bone / Q000473:pathology; D014057:Tomography, X-Ray Computed