A 39-year-old man presented with a 1-year history of dyspnea on exertion and a single episode of hemoptysis. Medical history was also significant for 15-pack-per-year cigarette use and mild intermittent asthma. Physical examination revealed diffuse bilateral wheezing and decreased air entry with hyperresonant percussion at the right lower lung. Laboratory results were normal. Chest radiograph (image A, arrow) demonstrated a giant right pulmonary bulla, supporting the diagnosis of vanishing lung syndrome. Partial right lung lobectomy was performed 8 months later, and a chest radiograph showed resolution of the bulla (image B, arrow). 

Vanishing lung syndrome is a chronic progressive condition. It is defined as bullae occupying at least one-third of the hemithorax.¹ Risk factors include tobacco use, male sex, α-1-antitrypsin deficiency, and marijuana use.^2-3 Tension pneumothorax is a potentially life-threatening complication. Although bullectomy is the treatment of choice, indications for surgical intervention should be individually assessed.⁴