title: Histopathological classification of refractory chronic rhinosinusitis with nasal polyps.
abstract: OBJECTIVE
  To delineate the histopathological characteristics of nasal mucosa in refractory chronic rhinosinusitis with nasal polyps (CRSwNP) in order to demonstrate subtypes of nasal polyps and their potential relation with lower airway comorbidity.
  
  
  METHODS
  Clinical- and pathological-based cross-sectional study Methods: Nasal polyp specimens were prospectively collected from patients with refractory CRSwNP referred to our institution for endoscopic sinus surgery. Oral and topical steroids were stopped 1 month before surgery. The pathological analysis was conducted by 2 independent reviewers with light microscopy on Hematoxylin-Eosin-Saffron stained slides. Each observer fulfilled a standardized protocol with cell count and stromal characterization on the most representative field. Mean grading scores were established. Morphological aspects were compared with the cell distribution and the clinical conditions.
  
  
  RESULTS
  Among 36 patients, three subtypes of nasal polyps were depicted: eosinophilic edematous (64%), fibrous (9%) and intermediate with mixed edematous and collagen stromal structure (27%). Basement membrane thickening and seromucous gland hyperplasia were observed in the fibrosis sub-type (p<0.03). Eosinophilic mucosal infiltrate was significantly increased (p=0.026) in patients with concomitant pulmonary disease (n=21). Nasal polyp distribution was not influenced by asthma, allergy, previous surgery and smoking.
  
  
  CONCLUSIONS
  Our 3-subtype classification of refractory CRSwNP in Caucasian population shows a predominant edematous structure whatever the clinical conditions may have been. Eosinophilia as a major factor of adaptive immune response in nasal inflammation is a feature of concomitant pulmonary disease. Further studies concerning mucosal remodelling and outcome assessment after sinus surgery are required to evaluate the impact of our classification on a daily basis.
authors.affiliation: Otorhinolaryngology - Head and Neck Surgery Department, University Hospital of Lille, France and EA 2686- French Eosinophil Network, University Hospital of Lille, Lille, France. geoffrey.mortuaire@chru-lille.fr.
authors.forename: G
authors.initials: G
authors.lastname: Mortuaire
authors.affiliation: Pathology Department, University Hospital of Lille, France. Lille.
authors.forename: X
authors.initials: X
authors.lastname: Leroy
authors.affiliation: Otorhinolaryngology - Head and Neck Surgery Department, University Hospital of Lille, Lille, France.
authors.forename: I
authors.initials: I
authors.lastname: Gengler
authors.affiliation: Otorhinolaryngology - Head and Neck Surgery Department, University Hospital of Lille, Lille, France.
authors.forename: D
authors.initials: D
authors.lastname: Chevalier
authors.affiliation: EA 2686- French Eosinophil Network, University Hospital of Lille, Lille, France.
authors.forename: L
authors.initials: L
authors.lastname: Prin
authors.affiliation: Otorhinolaryngology - Head and Neck Surgery Department, University Hospital of Lille, Lille, France.
authors.forename: A
authors.initials: A
authors.lastname: Picry
mesh_terms: D001485:Basement Membrane / Q000473:pathology; D002452:Cell Count; D002908:Chronic Disease; D003094:Collagen / Q000378:metabolism; D003430:Cross-Sectional Studies; D004487:Edema / Q000473:pathology; D004804:Eosinophils / Q000473:pathology; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000150:complications / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000473:pathology; D009298:Nasal Polyps / Q000145:classification* / Q000473:pathology; D011446:Prospective Studies; D012220:Rhinitis / Q000145:classification* / Q000473:pathology; D012852:Sinusitis / Q000145:classification* / Q000473:pathology; D044465:White People
chemical_list: D003094:Collagen