title: The presentation and clinical significance of sinonasal respiratory epithelial adenomatoid hamartoma (REAH).
abstract: BACKGROUND
  Sinonasal respiratory epithelial adenomatoid hamartoma (REAH) is a benign glandular proliferation with ciliated epithelium. Little is known about REAH, with only a few published case reports appearing since its original description in 1995. Classically described as an isolated polypoid lesion arising from the nasal septum, more recent descriptions also suggest that REAH can occur among nasal polyps. We report the largest experience with REAH to date, and aim to better understand and characterize this unique entity.
  
  
  METHODS
  In this case series, all cases of REAH diagnosed between 2006 and 2011 were reviewed. Clinical presentation, histologic and radiographic features, and operative findings were examined.
  
  
  RESULTS
  There were 45 patients 19 females and 26 males, with a mean age of 55.9 years (range, 23-83). Most cases of REAH (33/45, 73%) were found in association with another pathologic process (sinonasal polyposis, adenoiditis, hereditary hemorrhagic telangiectasia [HHT], inverted papilloma [IP], or malignancy). Of these, REAH occurring among diffuse polyposis (79% of cases) represented the large majority. The average Harvard computed tomography (CT) stage for this cohort was 3.1. The other presentation of REAH (12/45, 27%) was an isolated sinonasal mass. In cases of isolated REAH, the majority of lesions (75%) were noted to be originating in the olfactory clefts.
  
  
  CONCLUSIONS
  Isolated REAH, which may mimic a neoplasm, appears to be a different clinical entity than the more common form encountered in association with nasal polyps and inflammation. Further investigation into the etiology and clinical significance is needed.
authors.affiliation: Head and Neck Institute, Section of Rhinology, Sinus and Skull Base Surgery, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Hawley
authors.forename: Sheila
authors.initials: S
authors.lastname: Pabon
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Hoschar
authors.forename: Raj
authors.initials: R
authors.lastname: Sindwani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002923:Cilia / Q000473:pathology; D015897:Comorbidity; D005260:Female; D006222:Hamartoma / Q000453:epidemiology / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009668:Nose Diseases / Q000453:epidemiology / Q000473:pathology*; D010256:Paranasal Sinuses / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D015995:Prevalence; D020545:Respiratory Mucosa / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D055815:Young Adult