Intrabronchiolar Involvement in Early Stage Pulmonary Sarcoidosis Presenting as Air Trapping: A Case Report

Abstract

Pulmonary sarcoidosis can be expressed only as a mosaic pattern of air trapping on an expiratory high-resolution computed tomography (HRCT) scan in the early stage, without the typical findings of pulmonary involvement. This radiologic finding indicates small airway disease, but the site of airflow obstruction and the type of involvement have only been speculated about thus far. We describe herein a female with proven sarcoidosis stage I whose HRCT scan showed air trapping during expiration and lung biopsy via video-assisted thoracoscopy (VAT) revealed air trapping-related emphysema and non-necrotizing granulomas with peribronchiolar compression and intrabronchiolar involvement. These findings could explain the impaired diffusion capacity and limited mid-expiratory flow rate in the pulmonary function test, and were compatible with a radiologic mosaic pattern. Her airway obstruction and oxygenation improved after oral corticosteroid treatment.