Medical Image of the Month: Giant Bulla

Figure 1. A chest radiograph demonstrates marked oligemia of the left lung with displacement of the cardiomediastinal silhouette to the right. Subtle, linear lung parenchymal markings are noted in the base of the left lung hinting at extensive bullous disease and not a pneumothorax (red arrows).

Figure 2. A CT of the chest with contrast in lung windows demonstrates a giant bulla centered in the left upper lobe. Adjacent bullous disease is also present.

Clinical Background: A 49-year-old gentleman with an extensive smoking history who was transferred from an outside hospital for higher level of care for management of his acute hypoxemic respiratory failure. His outside chest radiograph (Figure 1) demonstrated marked oligemia of the left lung with displacement of the cardiomediastinal silhouette to the right. Subtle linear parenchymal markings are noted in the lower lobe suggesting bullous disease. There is extensive airspace disease of the right lung. A CT of the chest (Figure 2) demonstrated extensive bullous disease with a giant bulla noted in the left upper lobe. The patient was transferred to the MICU for further management of his hypoxemic respiratory failure. A CT surgery consult was obtained, and he was deemed not to be a surgical candidate given his tenuous clinical status.

Discussion: A bulla is defined as an air-containing space measuring greater than 1 cm in diameter and surrounded by a thin wall which is less than 1 mm thick. Bulla are usually located in a subpleural location and can be seen with emphysema - both paraseptal and centrilobular types. A giant bulla is defined as a bulla occupying at least 30% of a hemithorax. In this case, the patient had a giant bulla centered in the left upper lobe.

Giant bullae typically develop because of long-term cigarette smoking, which is the most likely cause in this case. Bullous lung disease has also been associated with HIV infection and intravenous use of methadone, methylphenidate, or talc-containing drugs.

In asymptomatic patients, smoking cessation is recommended to prevent further progression. In dyspneic patients with COPD, medical therapy with bronchodilators, inhaled corticosteroids, supplemental oxygen, and pulmonary rehab are recommended. In patients who have dyspnea despite medical optimization or who have issues with a spontaneous, secondary pneumothorax, a bullectomy may be beneficial. Contraindications to a bullectomy include ongoing cigarette smoking, significant comorbid disease, poorly-defined bullae on chest imaging, pulmonary hypertension, and other comorbid conditions that make surgery high risk.

Leslie Littlefield MD and Mohammed Fayed MD

UCSF Fresno

Fresno, CA USA

References

1. Rosado-de-Christenson M, Abbott GF. Diagnostic Chest Imaging. 2^nd edition. Canada: Amirsys; 2012; Section 1, p 15.
2. Diaz PT, Clanton TL, Pacht ER. Emphysema-like pulmonary disease associated with human immunodeficiency virus infection. Ann Intern Med. 1992 Jan 15;116(2):124-8. [CrossRef] [PubMed]
3. Palla A, Desideri M, Rossi G, Bardi G, Mazzantini D, Mussi A, Giuntini C. Elective surgery for giant bullous emphysema: a 5-year clinical and functional follow-up. Chest. 2005 Oct;128(4):2043-50. [CrossRef] [PubMed]

Cite as: Littlefield L, Fayed M. Medical image of the month: giant bulla. Southwest J Pulm Crit Care. 2019;19(4):125-6. doi: https://doi.org/10.13175/swjpcc040-19 PDF

Medical Image of the Week: Infected Emphysematous Bulla

Figure 1. Portable AP chest X-ray revealing dense opacity within the lingula of left lung.

Figure 2. Thoracic CT with contrast showing lobar consolidation with increased lucency compatible with emphysema.

Figure 3. (A) Chest CT one year prior demonstrating severe emphysema. (B) Chest CT on admission showing new fluid-filled bulla (red arrow) in the setting pneumococcal pneumonia.

A 65 year-old man with chronic obstructive lung disease (COPD), hypertension and alcohol abuse presented to the emergency department with complaints of feeling unwell and shortness of breath. He was tachycardic but otherwise hemodynamically stable, afebrile, and requiring 3 liters/min supplemental oxygen. Pertinent initial laboratory findings revealed a neutrophilic predominant leukocytosis (WBC 37.8 x 10³ micro/L) with lactic acidosis (2.7 mMol/L). Chest radiograph showed a dense opacity within the region of the lingula (Figure 1). Follow-up CT chest confirmed a consolidation likely representing lobar pneumonia in the setting of severe bullous emphysema (Figure 2). A large fluid-containing emphysematous bulla (Figure 3) was present which was not visualized one year prior. 

He was started on broad spectrum antibiotics after peripheral blood cultures were drawn which revealed Streptococcus pneumoniae. Broad spectrum antibiotics were discontinued and patient was started on intravenous ceftriaxone 2g every 24 hours. He improved clinically and was discharged home after 4 days.

Pneumococcal pneumonia remains the most common cause of community-acquired pneumonia and accounts for nearly 66% of all bacteremic pneumonias (1,2). Our patient had multiple risk factors for developing pneumococcal pneumonia including alcohol abuse, COPD, and history of cigarette smoking. Pneumococcal pneumonia often causes dense consolidation within the lung in a well-defined lobar or segmental distribution. In emphysema areas of lucency may be seen within the consolidation which may mimic other processes such as necrosis. The pathogenesis of fluid accumulation in an emphysematous bulla is not well understood but can be associated with severe lung infection (3). Percutaneous drainage is not recommended and bronchoscopy is not usually required unless there is another indication (3). Antibiotic therapy in those who are asymptomatic has not shown to add any benefit in resolution or preventing infection (3).

Norman Beatty MD¹, Kyle McKeown MPH², Kelly M. Hager MPH², and Stephen J. Scholand MD³

¹ Department of Medicine, Banner-University Medical Center South, Tucson, AZ USA

² University of Arizona College of Medicine, Tucson, AZ USA

³ Division of Infectious Diseases, Department of Medicine, MidState Medical Center, Meriden, CT USA

References

1. Torres A, Peetermans WE, Viegi G, Blasi F. Risk factors for community-acquired pneumonia in adults in Europe: a literature review. Thorax. 2013 Nov;68(11):1057-65. [CrossRef] [PubMed]
2. Fine MJ, Smith MA, Carson CA, Mutha SS, Sankey SS, Weissfeld LA, Kapoor WN. Prognosis and outcomes of patients with community-acquired pneumonia. A meta-analysis. JAMA. 1996 Jan 10;275(2):134-41. [CrossRef] [PubMed]
3. Chandra D, Rose SR, Carter RB, Musher DM, Hamill RJ. Fluid-containing emphysematous bullae: a spectrum of illness. Eur Respir J. 2008 Aug;32(2):303-6. [CrossRef] [PubMed]

Cite as: Beatty N, McKeown K, Hager KM, Scholand SJ. Medical image of the week: infected emphysematous bulla. Southwest J Pulm Crit Care. 2016;14(1):37-8. doi: https://doi.org/10.13175/swjpcc006-17 PDF