Epidemiology and differential diagnosis of nasal polyps

Abstract

Background: Chronic rhinosinusitis (CRS) is one of the most common chronic medical conditions, with a significant impact on patient quality of life. CRS is broadly classified into two groups: CRS with nasal polyposis (CRSwNP) and CRS without NP (CRSsNP). Clinically, the major subtypes of CRSwNP may be divided into eosinophilic chronic rhinosinusitis (e.g., allergic fungal rhinosinusitis and aspirin-exacerbated respiratory disease [AERD]) and nasal polyps associated with neutrophilic inflammation (e.g., cystic fibrosis [CF]). CF is characterized by mutation of the gene encoding the CF transmembrane conductance regulator. Functional endoscopic sinus surgery is usually required for most NP patients with increased frequency in patients with AERD. This study provides a review of the epidemiology and major classification of CRSwNP.

Methods: A review was performed of the literature regarding different subtypes of CRSwNP.

Results: Many definitions of CRSwNP exist and estimates of prevalence vary.

Conclusion: CRSwNP is a clinical syndrome with a heterogeneous inflammatory profile. Of the subtypes associated with eosinophilic inflammation, AERD remains the most recalcitrant to medical and surgical therapeutic interventions.

Figure 1.

Endoscopic view of allergic fungal mucin.

Figure 2.

Coronal computed tomography (CT) scan of the paranasal sinuses with soft tissue windows showing unilateral opacification of the maxillary and ethmoid sinuses with bony erosion into the skull base (black arrow) as well as expansion into the left orbit. Note the characteristic hyperattenuated areas in the maxillary sinus suggestive of allergic fungal rhinosinusitis (AFRS; white arrow).

Figure 3.

Intraoperative triplanar imaging and endoscopic view after removal of fungal mucin shows widespread skull base erosion typical for allergic fungal rhinosinusitis (AFRS).