eMedicine Specialties > Radiology > Chest

Bronchogenic Cyst

Eric Goodman, MD, Associate Clinical Professor, Department of Radiology, University of California San Diego Medical Center

Updated: Dec 29, 2008

Introduction

Bronchogenic cyst. Anteroposterior view on conventional radiograph demonstrates a mass in the aorto-pulmonary window.

Bronchogenic cyst. Anteroposterior CT demonstrates a mass with fluid density.

Bronchogenic cyst. Axial T2-weighted MRI demonstrates a high signal mass in the right paratracheal region.

Background

Bronchogenic cysts are congenital in nature. They are part of a spectrum of congenital abnormalities of the lung, including pulmonary sequestration, congenital cystic adenomatoid malformation, and congenital lobar hyperinflation (emphysema).^1,2,3

Related eMedicine topics:

Bronchogenic Cyst (Pediatrics: General Medicine)

Pulmonary Sequestration (Radiology)

Pulmonary Sequestration (Pediatrics: General Medicine)

Congenital Cystic Adenomatoid Malformation

Emphysema

Frequency

United States

The frequency of bronchogenic cysts is unknown, presumably because most patients are asymptomatic. Numerous studies have documented the rare incidence of bronchogenic cysts, with the average incidence being 20 cases over a 20-year period.

International

International frequency is unknown.

Mortality/Morbidity

Although bronchogenic cysts are usually an incidental finding, morbidity associated with bronchogenic cysts has been reported as occurring because the cyst becomes secondarily infected or because postobstructive pneumonia occurs. Dysphagia and dyspnea have resulted from compression of a large cyst on the esophagus and airways. Cases have been reported of cyst rupture and hemorrhage within the cyst.

Race

The frequency in different races is unknown.

Sex

Frequency in each sex is unknown.

Age

Bronchogenic cysts are congenital lesions. Large cysts may present in the pediatric population because of compression of the esophagus or trachea or because of infection. In adults, the cysts typically present as an incidental mass in either the mediastinum or the lung.

Presentation

Natural history and presentation

Bronchogenic cysts are located most commonly in the mediastinum (85%). Other common locations include subcarinal, paratracheal, and retrocardiac sites. Intrapulmonary bronchogenic cysts are less common (15%).

Histologically, cysts are thin walled, filled with mucoid material, and lined with columnar respiratory epithelium, mucous glands, cartilage, elastic tissue, and smooth muscle. Bronchogenic cysts develop from an abnormal budding of the ventral foregut between the 26th and 40th week of gestation. As such, they are often more appropriately termed foregut duplication cysts.

In the pediatric population, bronchogenic cysts present as fever or difficultly breathing. Adults with bronchogenic cysts are usually asymptomatic. Patients with large mediastinal cysts may present with stridor or dysphagia resulting from a mass effect on the trachea or esophagus.⁴

Occasionally, large cysts can be aspirated percutaneously for diagnostic or therapeutic indications.

Preferred Examination

Bronchogenic cysts are usually an incidental finding, and differentiating them from other pathologic conditions is important. On conventional radiographs, the appearances of mediastinal or lung masses are nonspecific and should be evaluated further using CT or MRI.^5,6

Limitations of Techniques

Chest radiograph is usually adequate for detecting larger mediastinal or lung masses; however, it is limited in its ability to differentiate solid masses from fluid.

CT findings are characteristic when the lesion demonstrates water density. If the lesion demonstrates soft-tissue density, differentiating the cyst from lymph nodes or other solid lesions is difficult.

MRI findings are usually diagnostic for mediastinal cysts.

Intrapulmonary cysts are difficult to diagnose and must usually be aspirated to confirm the diagnosis.

Differential Diagnoses

Other Problems to Be Considered

Metastatic disease to the mediastinum
Reactive lymph node
Abscess
Pneumatocele

Radiography

Bronchogenic cyst. Anteroposterior view on conventional radiograph demonstrates a mass in the aorto-pulmonary window.

Bronchogenic cyst. Lateral view on conventional radiograph demonstrates filling of the retrosternal clear space correlating to the abnormality observed on the frontal view.

Bronchogenic cyst. Conventional radiograph demonstrates a right paratracheal mass.

Bronchogenic cyst. Conventional radiograph demonstrates a subcarinal mass.

Bronchogenic cyst. Conventional radiograph demonstrates a subcarinal mass.

Bronchogenic cyst. Conventional radiograph demonstrates a thin-walled cyst in the left lower lobe with an air-fluid level.

Findings

Mediastinal cysts are visualized as a mediastinal mass on conventional radiographs. Intrapulmonary cysts usually present as a solitary pulmonary nodule unless the cyst contains air.

Degree of Confidence

On conventional radiographs, findings are nonspecific. Mediastinal masses should be evaluated further using CT or MRI to confirm the presence of fluid.

False Positives/Negatives

Difficulty is encountered in determining whether the visualized mass is benign (eg, a bronchogenic cyst) or malignant.

Computed Tomography

Bronchogenic cyst. Anteroposterior CT demonstrates a mass with fluid density.

Bronchogenic cyst. CT demonstrates a subcarinal mass with fluid density.

Bronchogenic cyst. CT demonstrates a thin-walled cyst in the right upper lobe.

Findings

Bronchogenic cysts are sharply marginated masses demonstrating water or soft-tissue density. Differences in attenuation result from the amount of proteinaceous fluid within the cysts. Cysts do not enhance after administration of IV contrast. An article from the Armed Forces Institute of Pathology documented the appearance of 62 cysts: 40% were water density, 40% were soft-tissue density, 5% contained milk of calcium, 10% were indeterminate from streak artifact, and the remainder were intrapulmonary, either completely air filled or containing an air-fluid level.⁷  In addition to intrapulmonary and mediastinal locations, bronchogenic cysts have been reported to be located in infradiaphragmatic areas, cutaneous areas, intrapericardial areas, and intramural areas of the esophagus.

Degree of Confidence

In the proper clinical setting, a CT finding of a sharply marginated, nonenhancing, water-density mass is diagnostic of a bronchogenic cyst. Nonenhancing masses demonstrating soft-tissue density need further evaluation using MRI. Location is also important. Intrapulmonary cysts are usually difficult to diagnose and usually require aspiration for diagnosis.

False Positives/Negatives

Most bronchogenic cysts are relatively characteristic in appearance on CT, but in atypical cases with hemorrhage or infection, findings may be confused with those of necrotic adenopathy, cystic lung disease, or lung abscess.

Magnetic Resonance Imaging

Bronchogenic cyst. Axial T2-weighted MRI demonstrates a high signal mass in the right paratracheal region.

Findings

Bronchogenic cysts are usually bright on T2-weighted images and dark on T1-weighted images. Cysts do not enhance after administration of IV gadolinium.

Degree of Confidence

On T2-weighted images, the brighter the cyst, the more confident the diagnosis of bronchogenic cyst. Lack of enhancement is also characteristic. Location is important in differentiating bronchogenic cysts from other cysts, such as pericardial cysts.

False Positives/Negatives

As with CT scans of typical bronchogenic cysts, MRI findings are very specific and few false-positive or false-negative findings occur. For atypical cysts, the main confusion is with necrotic tumors or infections.

Multimedia

Media file 1: Bronchogenic cyst. Anteroposterior view on conventional radiograph demonstrates a mass in the aorto-pulmonary window.

Media file 2: Bronchogenic cyst. Lateral view on conventional radiograph demonstrates filling of the retrosternal clear space correlating to the abnormality observed on the frontal view.

Media file 3: Bronchogenic cyst. Anteroposterior CT demonstrates a mass with fluid density.

Media file 4: Bronchogenic cyst. Conventional radiograph demonstrates a right paratracheal mass.

Media file 5: Bronchogenic cyst. Axial T2-weighted MRI demonstrates a high signal mass in the right paratracheal region.

Media file 6: Bronchogenic cyst. Conventional radiograph demonstrates a subcarinal mass.

Media file 7: Bronchogenic cyst. Conventional radiograph demonstrates a subcarinal mass.

Media file 8: Bronchogenic cyst. CT demonstrates a subcarinal mass with fluid density.

Media file 9: Bronchogenic cyst. Conventional radiograph demonstrates a thin-walled cyst in the left lower lobe with an air-fluid level.

Media file 10: Bronchogenic cyst. Conventional radiograph demonstrates a thin-walled cyst in the left lower lobe with an air-fluid level.

Media file 11: Bronchogenic cyst. CT demonstrates a thin-walled cyst in the right upper lobe.

References

1. Kumar AN. Perinatal management of common neonatal thoracic lesions. Indian J Pediatr. Sep 2008;75(9):931-7. [Medline].

2. Shah SK, Stayer SE, Hicks MJ, Brandt ML. Suprasternal bronchogenic cyst. J Pediatr Surg. Nov 2008;43(11):2115-7. [Medline].

3. Lima M, Gargano T, Ruggeri G, Manuele R, Gentili A, Pilu G, et al. [Clinical spectrum and management of congenital pulmonary cystic lesions]. Pediatr Med Chir. Mar-Apr 2008;30(2):79-88. [Medline].

4. Teissier N, Elmaleh-Bergès M, Ferkdadji L, François M, Van den Abbeele T. Cervical bronchogenic cysts: usual and unusual clinical presentations. Arch Otolaryngol Head Neck Surg. Nov 2008;134(11):1165-9. [Medline].

5. Cardinale L, Ardissone F, Cataldi A, Gned D, Prato A, Solitro F, et al. Bronchogenic cysts in the adult: diagnostic criteria derived from the correct use of standard radiography and computed tomography. Radiol Med. Apr 2008;113(3):385-94. [Medline].

6. Ko SF, Hsieh MJ, Lin JW, Huang CC, Li CC, Cheung YC, et al. Bronchogenic cyst of the esophagus: clinical and imaging features of seven cases. Clin Imaging. Sep-Oct 2006;30(5):309-14. [Medline].

7. McAdams HP, Kirejczyk WM, Rosado-de-Christenson ML, et al. Bronchogenic cyst: imaging features with clinical and histopathologic correlation. Radiology. Nov 2000;217(2):441-6. [Medline]. [Full Text].

8. Bolton JW, Shahian DM. Asymptomatic bronchogenic cysts: what is the best management?. Ann Thorac Surg. Jun 1992;53(6):1134-7. [Medline].

9. Cioffi U, Bonavina L, De Simone M, et al. Presentation and surgical management of bronchogenic and esophageal duplication cysts in adults. Chest. Jun 1998;113(6):1492-6. [Medline].

10. Hutchin P. Congenital cystic disease of the lung. Rev Surg. Mar-Apr 1971;28(2):79-87. [Medline].

11. Naidich DP, Muller NL, Zerhouni EA. Mediastinal cysts. In: Computed Tomography and Magnetic Resonance of the Thorax. 3rd ed. Philadelphia, Pa: Lippincott-Raven;1999:125-7.

12. Rogers LF, Osmer JC. Bronchogenic cysts: a review of 46 cases. Am J Roentgenol AJR. 1964;91:273-83.

Keywords

bronchogenic cyst, foregut cyst, duplication cyst, congenital cyst

Contributor Information and Disclosures

Author

Eric Goodman, MD, Associate Clinical Professor, Department of Radiology, University of California San Diego Medical Center
Eric Goodman, MD is a member of the following medical societies: American College of Radiology, American Roentgen Ray Society, North American Society for Cardiac Imaging, Radiological Society of North America, and Society of Cardiovascular Computed Tomography
Disclosure: Nothing to disclose.

Medical Editor

Kitt Shaffer, MD, PhD, Director of Undergraduate Medical Education, Associate Professor, Department of Radiology, Cambridge Health Alliance
Kitt Shaffer, MD, PhD is a member of the following medical societies: American Roentgen Ray Society
Disclosure: Nothing to disclose.

Pharmacy Editor

Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand
Disclosure: Nothing to disclose.

Managing Editor

Eric J Stern, MD, Professor of Radiology, Adjunct Professor of Medicine, Adjunct Professor of Medical Education and Biomedical Informatics, University of Washington School of Medicine; Director of Thoracic Imaging, Harborview Medical Center; Associate Medical Staff, Seattle Cancer Care Alliance
Eric J Stern, MD is a member of the following medical societies: American Roentgen Ray Society, Association of University Radiologists, European Society of Radiology, Radiological Society of North America, and Society of Thoracic Radiology
Disclosure: Nothing to disclose.

CME Editor

Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute
Robert M Krasny, MD is a member of the following medical societies: American Roentgen Ray Society and Radiological Society of North America
Disclosure: Nothing to disclose.

Chief Editor

Barry H Gross, MD, Professor, Department of Radiology, University of Michigan Medical School; Professor, University of Michigan Cancer Center
Barry H Gross, MD is a member of the following medical societies: American College of Chest Physicians, American College of Radiology, American Roentgen Ray Society, Association of University Radiologists, Michigan State Medical Society, Physicians for Social Responsibility, Radiological Society of North America, and Society of Thoracic Radiology
Disclosure: Nothing to disclose.

Related eMedicine topics:

Bronchogenic Cyst (Pediatrics: General Medicine)

Pulmonary Sequestration (Radiology)

Pulmonary Sequestration (Pediatrics: General Medicine)

Congenital Cystic Adenomatoid Malformation

Emphysema

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