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Description
A 56-year-old white woman with a history of chronic obstructive pulmonary disease, hypertension, deep vein thrombosis and chronic alcohol abuse was brought to the emergency room after having two episodes of seizures at home. She was confused and could not give any history. Vital signs were stable and limited neurological exam was unremarkable except for confusion. CT scan of the head was negative for any acute intracranial abnormality and she was admitted for presumed alcohol withdrawal. Soon after admission, she developed shortness of breath, tachycardia and a low-grade fever. On auscultation, she was found to have no breath sounds on the right and a chest X-ray was obtained which showed a large lucency occupying the majority of the right hemithorax (figure 1). The next question for us was if this was a tension pneumothorax and if the patient needs an urgent tube thoracostomy. However, because of the history of bullous chronic obstructive pulmonary disease and deep vein thrombosis, we obtained a CT scan of the chest to exclude giant bulla mimicking pneumothorax and/or pulmonary embolism. CT scan excluded pulmonary embolism and demonstrated a large lucency on the right hemithorax together with bilateral chronic emphysematous changes (figure 2) and basal opacities suggestive of aspiration. There were no signs suggestive of accompanying pneumothorax such as air outlining both sides of the bulla wall parallel to the chest wall (known as the ‘double wall sign’).1 The patient’s clinical status improved with supplemental oxygen and intravenous antibiotic therapy. She opted against bullectomy and was asymptomatic at discharge.
Chest X-ray demonstrating a large lucency (arrow) occupying majority of the right hemithorax.
Coronal (A) and transverse (B) views of the CT scan of the chest demonstrating the giant pulmonary bulla (arrows) on the right without pneumothorax; chronic emphysematous changes can be seen in the background.
Learning points
Bullous emphysema is typically seen in patients with chronic obstructive pulmonary disease, and when bullae occupy more than 30% of hemithorax, they are called ‘giant bullae.’2
Giant bullae can mimic pneumothorax and a CT scan is required in such cases to avoid misdiagnosis and unnecessary procedures.
An important differentiating factor between these two entities on imaging is that the lung collapses towards the ipsilateral hilum unless there are adhesions in case of pneumothorax, while the lung is draped around the bulla with the giant pulmonary bulla.3
Footnotes
Contributors AK has prepared the manuscript. VB has reviewed and revised the manuscript and approved for final submission.
Competing interests None declared.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.