Case report

A 38-year-old previously fit smoker of 10 pack-years presented with 1 month of progressive worsening exertional dyspnoea. He had no cough, chest pain nor constitutional symptoms. Auscultation of the chest revealed widespread crepitations. Oxygen saturation was 96% on room air, desaturating to 88% after mild exertion. Chest radiograph showed diffuse nodular interstitial infiltrates with significant peribronchial cuffing. CT thorax revealed multiple Cheerio signs of varying sizes and wall thickness, distributed evenly bilaterally (figure 1). There was significant interlobular septal thickening with thickened peribronchovascular bundles, and a thick-walled cavitation in the left lower lobe. Flexible bronchoscopy was performed under fluoroscopy via endotracheal tube. Radial endobronchial ultrasound (R-EBUS) examination at all visible subsegmental branches of the lateral segment of the right lower lobe demonstrated multiple scattered hyperechoic linear arcs and dots, representing patent airspaces (figure 2A,B, arrow). Transbronchial lung cryobiopsy was performed uneventfully at the site of the R-EBUS examination. Histopathological examination revealed invasive lung adenocarcinoma with predominantly micropapillary and …