DISCUSSION: VLS is characterized by the coalescence of adjacent areas of paraseptal emphysema to form giant bullae with a marked predisposition for the upper lobes. Risk factors include alpha 1 antitrypsin deficiency, and tobacco, marijauana, and cocaine smoking. In patients who smoke marijauana and cocaine, the pathological changes are known to occur earlier in life, by about 20 years. Radiologically, VLS is defined by the finding of giant bullae in one or both lungs, occupying at least one third of the hemithorax and compressing the surrounding lung parenchyma. CT scan of the chest plays a key role in management. The large size and apical location of the bullae pose a challenge to differentiate from pneumothorax on chest X-ray. CT scan also shows the extent and distribution of the bullae for preoperative assessment. Treatment of VLS is usually surgical bullectomy, especially when the patient is symptomatic or develops pneumothorax.