Aspirated Soybean Mimicking Endobronchial Tumour Removed With a Cryoprobe

Adult airway foreign bodies are misdiagnosed as endobronchial tumours on imaging. A 77-year-old man with asbestosis presented with a worsening cough. Computed tomography (CT) showed a 12-mm low-attenuation right upper-lobe bronchial lesion with distal bronchiectasis and infiltrates. Magnetic resonance imaging (MRI) suggested a fat-containing tumour (lipoma or hamartoma). Flexible bronchoscopy revealed a yellowish polypoid mass; poor sedation tolerance necessitated rigid bronchoscopy under general anaesthesia. Using a 1.7-mm cryoprobe, the lesion was cryoactivated for 10 s and removed en bloc. It proved to be a foreign body resembling a legume and was later confirmed to be an aspirated soybean from 1 month earlier. The fat and water content of soybeans can yield MRI appearances similar to fatty tumours. Distinguishing tumours from foreign bodies by imaging or bronchoscopy alone is challenging. Cryoprobe extraction is effective for hydrated foreign bodies, and aspiration should be considered in the differential diagnosis of endobronchial tumours.