title: A Rare Case of Aneurysmal Bone Cyst in the Paranasal Sinus.
abstract: BACKGROUND
  Aneurysmal Bone cysts (ABC) are extremely rare in the head and neck region and even rarer in sinuses. ABC is a benign multicystic mass that is locally-destructive and rapidly expandable. Hemorrhagic fluid content (like in this case) and septated appearance are the characteristic feature of ABC. Established treatment options for ABCs include sclerotherapy, embolization, radiotherapy, simple curettage, surgical excision, or a combination of methods.
  
  
  METHODS
  In this article, a 5 year-old boy with a recurrent nasal mass is presented. The patient was finally diagnosed with this rare entity: ABC of the paranasal sinuses. The patient was treated through complete surgical removal.
  
  
  CONCLUSIONS
  ABC can be considered as a rare differential diagnosis of recurrent nasal hemorrhagic mass in a pediatric population.
authors.affiliation: Department of Otorhinolaryngology, Kashani Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Seyyed Mostafa
authors.initials: SM
authors.lastname: Hashemi
authors.affiliation: Department of Pathology, Kashani Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mitra
authors.initials: M
authors.lastname: Heidarpour
authors.affiliation: Department of Otorhinolaryngology, Kashani Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Afrooz
authors.initials: A
authors.lastname: Eshaghian
authors.affiliation: Department of Radiology, Kashani University of Medical Sciences, Isfahan, Iran.
authors.forename: Peyman
authors.initials: P
authors.lastname: Ansari
authors.affiliation: General Practitioner, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Maryam Sadat
authors.initials: MS
authors.lastname: Hashemi
authors.affiliation: Department of Otorhinolaryngology, Kashani Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Yaghoobi
authors.affiliation: Department of Otorhinolaryngology, Kashani Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Sohrab
authors.initials: S
authors.lastname: Barati
keywords: Aneurysmal Bone Cysts (ABC); Angiofibroma.