Giant bullous emphysema

Clinical History

A 40-year-old man, smoker (24 pack/years), with progressive shortness of breath over the previous 12 months, underwent a chest x-ray examination.

Imaging Findings

PA and lateral films were performed, revealing diffuse hyperlucency in the right hemithorax, mostly without lung markings. Pneumothorax was a concern, but visceral pleural line wasn’t clearly visible. Little mediastinal shift to the left side was noted. These findings were similar to older chest x-ray films of the patient, from the previous years, and the patient hadn’t acute symptoms.
Later, a CT scan was performed, showing giant pulmonary bullae in the right upper lobe, extending from the apex to the base of the right lung, with massive compression of the remaining lung parenchyma, being almost totally collapsed. A few septae were seen in the bullae, and no air was seen outlining external side of the bulla wall.
In the left upper lung, there was parasseptal and centrilobular emphysema, with formation of bullae in the apex region measuring up to 5cm. There were no signs of pneumothorax.

Discussion

Emphysema is a condition associated with progressive damage of alveoli leading to destruction of normal functioning lung parenchyma, and resulting in airspace enlargement. Although most frequently of small size (<1cm), in some cases emphysema is associated with bigger airspace enlargement, called pulmonary bullae (>1cm), which can grow significantly, compressing normal lung parenchyma [1,2].

This entity is frequently observed in middle-age males, most of whom are smokers. It was firstly described by Burke in 1937, being nowadays called giant bullous emphysema, primary bullous disease or vanishing lung syndrome. [3]
Its etiology is not fully understood, but some authors refer association with smoking, alpha-1 antitrypsin deficiency and drug abuse. [2]

The main finding is the presence of one or more giant bullae, usually in the upper lobes, causing compression of the adjacent lung parenchyma. [4]
CT scans have a major role in this disease, detecting emphysema, its type and extension and helping to differentiate giant bullae from pneumothorax.
In terms of clinical presentation of giant bullous emphysema, commonly there’s a history of chronic progressive dyspnea over several months. In the opposite, pneumothorax is associated with an acute sudden chest pain and acute shortness of breath.
Pneumothorax can be diagnosed when the visceral pleural edge is clearly demarcated with no lung markings laterally to this line. Expiratory films are useful to detect small pneumothoraxes. [3]
The double wall sign helps to identify a pneumothorax in patients with giant bullae, occurring when one sees air in both sides of the bulla wall, paralleling the chest wall, indicating the presence of pneumothorax. [3]

If the patients are asymptomatic, the treatment is conservative, consisting of reassurance, advice to quit smoking and some activities like scuba diving. [5]
Symptomatic patients with progressive dyspnea should undergo bullectomy. [6]
Bullectomy reduces compression of adjacent lung parenchyma with significant respiratory and functional benefits in the early postoperative period. [5]

Written informed patient consent for publication has been obtained.

Differential Diagnosis List

Final Diagnosis

Giant bullous emphysema

URL:	https://eurorad.org/case/16102
DOI:	10.1594/EURORAD/CASE.16102
ISSN:	1563-4086