A 6-year-old child with cystic fibrosis presents with persistent nasal obstruction and recurrent sinusitis despite medical management. Nasal endoscopy reveals multiple polyps. Which investigation is most appropriate to assess for associated complications and guide management?

Explanation

## Investigation of Choice for Nasal Polyps in Cystic Fibrosis ### Clinical Context This child has: - Cystic fibrosis (CF) — a strong risk factor for nasal polyps - Persistent nasal obstruction - Recurrent sinusitis - Endoscopic confirmation of polyps ### Why HRCT is the Investigation of Choice **Key Point:** High-resolution CT (HRCT) of paranasal sinuses is indicated because: 1. CF patients have high rates of sinusitis and polyp recurrence 2. HRCT detects extent of sinus disease 3. Identifies complications (mucocele, orbital involvement) 4. Guides surgical planning 5. Monitors disease progression ### HRCT Findings in CF-Related Nasal Polyps | Finding | Significance | |---------|-------------| | Pansinusitis | Common in CF; indicates severity | | Nasal polyps | Often bilateral and extensive | | Sinus hypoplasia | CF-specific finding | | Mucoceles | Rare but serious complication | | Bone erosion | Suggests long-standing disease | **High-Yield:** HRCT is superior to plain imaging because it: - Provides detailed sinus anatomy - Detects subtle bone changes - Assesses extent of disease - Identifies complications requiring intervention ### Why Other Investigations Are Inadequate **Nasal Swab for Culture:** - Useful for identifying infectious organisms - Does NOT assess anatomical extent of disease - Does NOT guide surgical planning - Secondary to imaging in this context **IgE Level Estimation:** - Relevant for allergic polyps - CF-related polyps are NOT primarily allergic - Does not assess disease extent - Not indicated in this clinical scenario **Chest X-ray:** - Assesses pulmonary involvement in CF - Does NOT evaluate nasal/sinus pathology - Unrelated to nasal polyp management **Clinical Pearl:** In CF patients with nasal polyps, HRCT is essential because: - CF predisposes to aggressive sinus disease - Polyps are often extensive and recurrent - Complications are more common - Surgical planning requires detailed anatomy