Pinhole‐Like Central Bronchial Narrowing: A Rare Reversible Manifestation of Eosinophilic Bronchial Inflammation

Recurrent atelectasis is occasionally encountered in clinical practice but may be attributed to repeated respiratory infections without thorough investigation, potentially delaying the diagnosis of the underlying cause. We report a 78-year-old woman with well-controlled asthma who developed recurrent right middle lobe and lingular atelectasis. Bronchoscopy revealed severe pinhole-like narrowing of multiple central bronchi. Although allergic bronchopulmonary mycosis and post-infectious cicatricial stenosis were initially considered, characteristic eosinophilic mucus impaction was absent, and endobronchial biopsy demonstrated marked eosinophilic inflammation of the bronchial wall with airway remodelling. Oral corticosteroid therapy resulted in resolution of the atelectasis and improvement of the bronchial narrowing. This case highlights eosinophilic bronchial inflammation as a rare but reversible cause of central bronchial narrowing and underscores the diagnostic value of endobronchial biopsy in patients with unexplained recurrent atelectasis.