Vanishing lung syndrome (giant bullous emphysema): CT findings in 7 patients and a literature review

Abstract

Purpose: we reviewed the imaging findings in 7 patients with idiopathic giant bullous emphysema. This is a chronic, progressive condition usually affecting young male smokers and is characterized by giant emphysematous bullae, which commonly develop in the upper lobes. Extensive paraseptal emphysema coalesces to form giant bullae, compressing the normal lung parenchyma and often displacing it centrally. These bullae occupy at least one-third of a hemithorax.

Materials and methods: Seven patients with chest radiographic evidence of a bulla or bullae occupying at least one-third of a hemithorax, who had also been examined with high-resolution computed tomography (HRCT), were included in this retrospective study. On HRCT scans, the size, location, and distribution of the bullae were documented and categorized as either subpleural or central.

Results: The HRCT scan findings in all 7 study patients included numerous bullae ranging in size from a few centimeters in diameter to giant bullae nearly filling an entire hemithorax, mimicking a pneumothorax. Five of the 7 patients had extensive upper lobe predominant bullae, 4 of the 7 patients showed severe bilateral disease with asymmetric involvement, 2 of the 7 patients demonstrated left lung predominance and whereas 1 patient showed right lung predominant disease. All of our patients had subpleural bullae, had parenchymal fibrosis, another had extensive subcutaneous emphysema, and 1 had accompanying bronchiectasis.

Conclusions: The predominant findings on HRCT scans are extensive paraseptal emphysema coalescing into giant bullae. HRCT is helpful in confirming the diagnosis of VLS, assessing the degree of the disease, and providing information to guide treatment.