title: Osteoid osteoma of the ethmoid bone associated with dacryocystitis.
abstract: BACKGROUND
  Osteoid osteomas (OO) are small, benign osteoblastic lesions. Ethmoid bone OO has been very rarely reported so far.
  
  
  METHODS
  We report a case of a 16-year-old boy suffering from persistent epiphora and a mild pain in the area of median canthus, due to a bone density mass within the right ethmoid air cells extending to the ipsilateral right orbit. The mass was removed via an external ethmoidectomy approach. Histopathologic examination of the specimen set the diagnosis of OO. One year after the operation the patient is free of symptoms, while no recurrence occurred.
  
  
  CONCLUSIONS
  A case of ethmoid bone OO associated with dacryocystitis is reported. Although benign and rare, OO should be considered in differential diagnosis of the ethmoid bone osteoblastic lesions.
authors.affiliation: Department of Otolaryngology, University of Crete School of Medicine, Heraklion, Crete, Greece. vlachanas@yahoo.com
authors.forename: Vassilios A
authors.initials: VA
authors.lastname: Lachanas
authors.forename: Anastasios V
authors.initials: AV
authors.lastname: Koutsopoulos
authors.forename: Jiannis K
authors.initials: JK
authors.lastname: Hajiioannou
authors.forename: Argyto J
authors.initials: AJ
authors.lastname: Bizaki
authors.forename: Emmanuel S
authors.initials: ES
authors.lastname: Helidonis
authors.forename: John G
authors.initials: JG
authors.lastname: Bizakis
mesh_terms: D000293:Adolescent; D003607:Dacryocystitis / Q000150:complications* / Q000175:diagnosis* / Q000601:surgery; D003937:Diagnosis, Differential; D005004:Ethmoid Bone / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010017:Osteoma, Osteoid / Q000150:complications* / Q000175:diagnosis* / Q000601:surgery; D014057:Tomography, X-Ray Computed