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Pediatrics: General Medicine > Pulmonology
Bronchogenic Cyst
Article Last Updated: Dec 18, 2006
AUTHOR AND EDITOR INFORMATION
Section 1 of 11  
Author: Mary E Cataletto, MD, Associate Director, Division of Pediatric Pulmonology, Winthrop University Hospital; Associate Professor, Department of Clinical Pediatrics, State University of New York at Stony Brook
Mary E Cataletto is a member of the following medical societies: American Academy of Pediatrics, American Heart Association, and American Thoracic Society
Editors: Girish D Sharma, MD, Associate Professor, Department of Pediatrics, Rush University Medical Center, Rush Children's Hospital; Director of Pediatric Pulmonary Section and Rush Cystic Fibrosis Center; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Charles Callahan, DO, Professor, Deputy Chief of Clinical Services, Walter Reed Army Medical Center; David Pallares, MD, Clinical Assistant Professor, Department of Pediatrics, Division of Allergy and Immunology, University of Louisville; Michael R Bye, MD, Attending Physician, Pediatric Pulmonary Medicine, Columbia University Medical Center; Professor of Clinical Pediatrics, Division of Pulmonary Medicine, Columbia University College of Physicians and Surgeons
Author and Editor Disclosure
Synonyms and related keywords:
bronchogenic cyst, lung bud cyst, subcarinal cysts, mediastinal cyst, dysphagia, respiratory distress, pulmonary cyst, airway compromise
Background
Bronchogenic cysts, while relatively rare, represent the most common cystic lesion of the mediastinum. In infants and small children, these cysts can be life threatening when they compress vital structures. Subcarinal cysts, in particular, can pose life-threatening airway compromise. In infants, initial presentation may be respiratory distress. More than one half of patients are asymptomatic. The cysts are usually found using antenatal sonography and routine chest radiography and during evaluations for GI or cardiac symptomatology. Bronchogenic cysts are the result of anomalous development of the ventral foregut; they are usually single but may be multiple. They have been found all along the tracheoesophageal course, in perihilar or intraparenchymal sites, with a predilection for the area around the carina. They have also been described in more remote locations, including the interatrial septum, neck, abdomen, and retroperitoneal space.
Pathophysiology
Symptomatic patients usually present with symptoms related to cyst infection or compression of adjacent structures. Bronchogenic cysts can be diagnosed in infants with respiratory distress because of the frequency at the level of the carina. Partial obstruction of the trachea or bronchus with resultant emphysema may occur, and some reports have noted cases in which Swyer-James syndrome and asthma were initially considered. Less frequently, communications may develop between the cyst and airway. Both adenocarcinoma and rhabdomyosarcoma have been reported to arise. Cysts located within the abdomen may also produce symptoms because of infection or compression of adjacent structures, and hemorrhage has been reported in cysts with gastric mucosa.
Frequency
United States
Although rare, bronchogenic cysts are the second most common subtype of foregut cysts found in the middle mediastinum. Enterogenous cysts are the most common subtype of foregut cysts, representing up to 70%; bronchogenic cysts represent 7-15% of the cystic lesions of the foregut.
Mortality/Morbidity
Ribet's 1995 series reported a postoperative morbidity of 13.4%. This series included 45 adult and 24 pediatric cases over a 25-year period at the University of Lille in France.
Sex
No sex predilection is apparent.
Age
More than 50% of cases are diagnosed in patients older than 15 years.
History
- Chest pain and dysphagia are the most common symptoms in symptomatic adults; in infants, symptoms are most often produced as a result of airway or esophageal compression.
- In 1996, Aktogu and colleagues reported superior vena cava syndrome, tracheal compression, pneumothorax, pleurisy, and pneumonia in a series of 30 adult patients.
- Bronchogenic cysts should be considered in patients with recurrent pulmonary infections.
- Intra-abdominal cysts are rare. As with the mediastinal variety, most are asymptomatic; however, hemorrhage, infection, and compression of adjacent structures can be observed.
- The presence of symptoms is important in preoperative assessment because symptomatic patients are more likely to have perioperative difficulties.
- In 1995, Ribet and colleagues reported that 70.8% of children were symptomatic because 75% of the cysts were in a critical area around the level of the carina. Approximately 60% of adults in this series were symptomatic, and 53% of those mediastinal cysts were at or above the carina.
Physical
- Location is more important than cyst volume in its association with symptoms of compression.
- Signs of airway compression are more frequently observed in infants and small children than in adults.
- Cough, infection, and hemoptysis may also be observed.
Causes
Cysts are believed to result from abnormal development of the ventral foregut and lung budding during the first trimester.
Other Problems to be Considered
Congenital lobar emphysema
Cystadenomatous malformation
Swyer-James syndrome
Other mediastinal tumors
Postinfectious pseudocysts
Imaging Studies
- Conventional 2-view chest radiography and barium swallow are often sufficient to support a preoperative diagnosis. Additional clarification may be obtained using chest CT and MRI studies.
- Conventional 2-view chest radiography
- This typically shows a sharply demarcated spherical mass of variable size, most commonly located in the middle mediastinum around the carina.
- When the cyst is infected or contains secretions, it may appear as a solid tumor or may demonstrate an air fluid level.
- Esophagography: A barium swallow helps to define the mass and its effect on adjacent structures.
- Chest CT scan: Cysts appear as lesions with smooth borders and thin walls and may contain secretions, pus, or blood. Calcifications may also be observed.
- CT or MRI
- A homogeneous mass of moderate-to-bright intensity is observed on T2-weighted MRI.
- On T1-weighted images, lesions may vary in their intensity because of their protein content.
- The finding of a cystic lesion at the level of the carina on CT or MRI is most frequently associated with a bronchogenic cyst.
- In all other locations, diagnosis cannot be as reliably forecast.
Histologic Findings
Surgical specimens of excised bronchogenic cysts show cystic lesions lined by respiratory epithelium. Occasionally, cysts may contain gastric mucosa or bronchial cartilage. Differentiation between congenital and acquired cysts may be difficult, if not impossible, in the presence of coexisting infection. Image 4 shows the surgical pathology of a cystic lesion. The left side is a low-power view of a bronchogenic cyst showing cartilage and smooth muscle within the wall and cyst lined by ciliated columnar epithelium. The right side is a high-power view (40X) of the same slide, showing ciliated columnar epithelial lining of the cyst.
Surgical Care
- The criterion standard is complete surgical resection.
- Temporizing or palliative procedures such as transparietal, transbronchial, or mediastinal puncture and aspiration may be considered in cases in which patients are symptomatic and the situation for complete resection is not optimal.
Consultations
Preoperative anesthesia consultation is recommended, particularly in infants, because of concern with airway compromise and monitoring.
Drug therapy is not currently a component of the standard of care for this condition. See Treatment.
Complications
- Cyst-related complications such as infection, rupture, bleeding, and compression are common. A risk of malignant degeneration is also noted.
- Other reported complications include airway-cyst fistula, ulceration, and hemorrhage.
- Arrhythmias and superior vena cava syndrome may also develop.
Prognosis
- Long-term prognosis of asymptomatic bronchogenic cysts is unpredictable, and the potential risks are life threatening. Many surgeons support surgical resection in these patients.
- The case of symptomatic patients is much clearer now, and lobectomy is the standard treatment. No deaths or recurrences have been reported postresection.
Medical/Legal Pitfalls
- Failure to diagnose
- Failure to anticipate potential for expansion of the cyst or subsequent infection if not resected
| Media file 1:
Plain chest radiograph showing a left paraspinal mass. Photo courtesy of A Fruauff, MD. |
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Media type: X-RAY
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| Media file 2:
Esophagogram shows an anterior and lateral mass effect in the distal portion of the esophagus corresponding to the paraspinal mass in Image 1. Photo courtesy of A Fruauff, MD. |
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Media type: X-RAY
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| Media file 3:
Chest CT scan shows an increased soft tissue density in the left paraesophageal area. Photo courtesy of A Fruauff, MD. |
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Media type: CT
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| Media file 4:
The left side shows a low-power view of a bronchogenic cyst showing cartilage and smooth muscle within the wall and the cyst lined by ciliated columnar epithelium. The right side shows a high-power view (40X) of a bronchogenic cyst demonstrating the ciliated columnar epithelial lining. Photo courtesy of A Schuss, MD. |
 | View Full Size Image | |
Media type: Photo
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| Media file 5:
Extrapulmonary bronchogenic cyst. Unilocular cystic mass attached to mediastinal structures by a short pedicle. The inner surface is trabeculated, and the cyst contains mucinous material. The cyst measures 15 cm by 5 cm. Photo courtesy of K Kenigsberg, MD. |
 | View Full Size Image | |
Media type: Photo
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Bronchogenic Cyst excerpt Article Last Updated: Dec 18, 2006
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