A 42-year-old man from Delhi presents with a 3-year history of progressive nasal obstruction and rhinorrhea. Nasal endoscopy reveals bilateral smooth, pale, gelatinous masses arising from the lateral nasal wall near the ostiomeatal complex. Biopsy confirms benign fibrous tissue with inflammatory infiltrate. What is the most common etiology of nasal polyps in this patient?

Explanation

## Most Common Cause of Nasal Polyps **Key Point:** Chronic rhinosinusitis (CRS) is the most common etiology of nasal polyps, accounting for >90% of cases in the general population. ### Pathophysiology of CRS-Related Polyps Chronic inflammation of the sinonasal mucosa leads to: 1. Edema and accumulation of inflammatory exudate 2. Herniation of mucosa through areas of weakness (typically ostiomeatal complex) 3. Formation of benign polypoidal masses 4. Perpetuation by impaired mucociliary clearance and recurrent infections ### Clinical Features Supporting CRS Etiology | Feature | CRS-Related Polyps | Other Etiologies | |---------|-------------------|------------------| | **Bilaterality** | Common (>50%) | Less common | | **Site of origin** | Ostiomeatal complex, lateral wall | Variable | | **Associated sinusitis** | Present on imaging | May be absent | | **Age of onset** | 30–60 years | Variable | | **Response to steroids** | Good | Variable | **High-Yield:** The ostiomeatal complex is the most common site of origin because it is the area of maximal mucosal stress and poorest drainage. ### Differential Etiologies (Less Common) - **Aspirin sensitivity (Samter triad):** Causes polyps in <5% of cases; requires history of asthma + rhinitis + NSAID intolerance - **Cystic fibrosis:** Polyps occur in 7–48% of CF patients; typically presents in childhood; associated with pancreatic insufficiency and recurrent infections - **Allergic fungal sinusitis (AFS):** Rare; presents with thick, eosinophilic mucin; fungal culture positive; typically unilateral **Clinical Pearl:** Bilateral nasal polyps in a child should raise suspicion for cystic fibrosis and warrant sweat chloride testing; in adults, CRS is overwhelmingly more likely. ### Management Approach ```mermaid flowchart TD A[Nasal Polyp Diagnosed]:::outcome --> B{Bilateral?}:::decision B -->|Yes| C[CRS most likely]:::action B -->|No| D[Consider unilateral causes]:::action C --> E[CT PNS to assess sinusitis]:::action E --> F[Topical corticosteroids + saline]:::action F --> G{Response?}:::decision G -->|Good| H[Continue medical management]:::action G -->|Poor| I[Functional endoscopic sinus surgery]:::action D --> J[Rule out AFS, malignancy]:::action ``` [cite:FESS Endoscopic Sinus Surgery Ch 12]