Ultrasound findings in rare pulmonary and pleural disorders: a case-based review

Transthoracic ultrasound (TUS) is an established imaging modality for the diagnosis and bedside monitoring of pleural effusions, pneumothorax, inflammatory pleural disease, thoracic wall lesions, peripheral pulmonary consolidations, and interstitial lung diseases. Contrast-enhanced ultrasound (CEUS) further improves lesion characterization by differentiating viable inflammatory tissue from necrosis and abscess formation. While the sonographic appearance of common thoracic diseases is well described, ultrasound findings in rare pulmonary and pleural conditions remain insufficiently documented. This review presents the characteristic transthoracic ultrasound (TUS) findings in several uncommon thoracic disorders, including abscessing fire-eater's pneumonia after paraffin aspiration, tracheal hemangioma, thoracic wall hemangioma, biliopleural fistula following percutaneous transhepatic cholangiodrainage (PTCD), bronchial rupture with hemopneumothorax, spontaneous pneumomediastinum, esophagopleural fistula, diaphragmatic cyst, and post-traumatic diaphragmatic paralysis. The sonographic findings are correlated with the clinical presentation and complementary imaging modalities.