Vanishing lung syndrome mimicking pneumothorax

The National Emphysema Treatment Trial (NETT) showed that lung volume reduction surgery improved exercise capacity in patients with predominantly upper-lobe emphysema and survival improved in patients with both upper-lobe emphysema and a low exercise capacity. 2 The Endobronchial Valve for Emphysema Palliation Trial (VENT) demonstrated that endobronchial valve implantation improved lung function and exercise capacity in patients with advanced heterogeneous emphysema. 3 However, these advantages may come at the cost of increased complications or short-term mortality. 2 3 Vanishing lung syndrome, also termed primary bullous disease of the lung, is characterised by the development of multiple large pulmonary bullae, and CT can be used to confirm diagnosis and identify the presence of spontaneous pneumothorax. 4 The predominant findings on CT scans are extensive paraseptal (peripheral) emphysema coalescing into giant bullae, and the double wall sign is useful if an accompanying pneumothorax is suspected. 4 Patients with a giant bulla occupying more than one-third of the volume of the lung, a rare entity of advanced emphysema, were excluded from both NETT and VENT. 2 3 In patients with severe symptoms, resection of giant emphysematous bullae is the preferred treatment. 4 Bullectomy may produce functional improvement by reducing thoracic hyperinflation, improving respiratory mechanics and alleviating collapse of the adjacent functioning lung. 5