eMedicine Specialties > Radiology > Chest

Swyer-James Syndrome

Beverly P Wood, MD, MS, PhD, Professor, Departments of Radiology and Pediatrics, Division of Medical Education, Keck School of Medicine, University of Southern California

Updated: Sep 25, 2008

Introduction

Background

Swyer-James syndrome (SJS) is a manifestation of postinfectious obliterative bronchiolitis. In SJS, the involved lung or portion of the lung does not grow normally and is slightly smaller than the opposite lung. The characteristic radiographic appearance is that of pulmonary hyperlucency, caused by overdistention of the alveoli in conjunction with diminished arterial flow.^1,2,3,4,5

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Bronchiolitis Obliterans Organizing Pneumonia
Pediatrics, Pneumonia

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Pathophysiology

The lung is expected to grow by progressive alveolarization for a child's first 2-8 years. Thereafter, lung growth is related to hyperexpansion of existing alveoli. Swyer-James syndrome is a postinfectious syndrome in which hypoplasia occurs as a result of diminished vascularity and the arrest of progressive growth and alveolarization of the lung. Multifocal areas of air trapping may be seen. The pulmonary parenchymal pattern is similar to that of obliterative bronchiolitis.⁶

Frequency

United States

Swyer-James syndrome is uncommon. It has been described as occurring after Mycoplasma pneumoniae infection, Streptococcus pneumoniae infection, and severe respiratory syncytial virus infection.

Mortality/Morbidity

Swyer-James syndrome occurs as a complication of infection. It is followed by chronic lung disease, characterized by bronchiolar abnormality, air trapping, and abnormal lung dynamics during inspiration and forced expiration.

Age

When Swyer-James syndrome occurs in children younger than 8 years (ie, in children who are too young to have experienced complete alveolarization), the characteristic effects are decreased vascularity and lack of growth in the involved lung. Radiographically, the imaging findings of SJS appear a few months to a few years after the causative infection.

Anatomy

Patients with Swyer-James syndrome have a small lung; they experience compensatory overexpansion of the contralateral lung. Peripheral bronchi and bronchioles become "pruned" secondary to obliterative bronchiolitis. On CT, a mosaic pattern of hyperlucency is observed in areas of the lung that are affected by disease; small vessels and vascular occlusions are also observed in the abnormal areas.

Presentation

Typically, the child with Swyer-James syndrome had severe pneumonia earlier in life. SJS produces the following effects:

• Areas of lung hyperlucency
• Air trapping upon expiration
• Bronchial/bronchiolar disease with wheezing
• Unilateral small chest
• Physiologic changes evinced by abnormal time-attenuation curves during inspiration and forced expiration

Organisms causing the infection include respiratory syncytial virus, influenza virus, Mycoplasma pneumoniae, and staphylococcal and streptococcal infections.

During differential pulmonary function testing, the involved lung shows diminished flow and oxygenation, as well as prolongation of the forced expiratory volume in 1 second.^7,8,9,10

Preferred Examination

For patients with Swyer-James syndrome, chest CT with thin collimation sections on inspiration and expiration is the preferred examination.

Limitations of Techniques

The appearance of the lungs on forced expiration is important in the assessment of Swyer-James syndrome with CT; therefore, the patient's cooperation is essential. The patient should be placed in the prone position to help identify the typical mosaic pattern of SJS.

Differential Diagnoses

Airway Foreign Body
Bronchiolitis Obliterans Organizing Pneumonia
Bronchopulmonary Dysplasia
Congenital Lobar Emphysema
Emphysema

Other Problems to Be Considered

Bronchiolitis
Bronchial adenoma
Bronchial granuloma

Radiography

Findings

• The typical appearance of Swyer-James syndrome is that of a hyperlucent but small lung, with overexpansion of the contralateral lung.
• A comparison of progressive radiographs shows failure of growth in the involved lung.
• A diffuse pattern of scarring or irregular vessels may be present.
• Fluoroscopy shows little change in volume in the involved lung with respiration (see Images 1-6).

Degree of Confidence

The disparity in size between the 2 lungs may represent a hypoplastic pulmonary artery or congenital hypoplasia of the lung. A comparison with a previous set of radiographs helps with the differential diagnosis. A history of severe lung infection also helps in making the diagnosis.

Computed Tomography

Findings

In Swyer-James syndrome, the bronchi have a pruned appearance. A mosaic pattern of air trapping in acini is seen, along with air trapping during expiration. The appearance is similar to that of hypoplastic lung syndrome.^11,12

False Positives/Negatives

The appearance of Swyer-James syndrome is the same as that of bronchiolitis obliterans, but bronchiolitis obliterans is more frequently a diffuse process.

Magnetic Resonance Imaging

Findings

In Swyer-James syndrome, the pulmonary vessels of the affected lung appear smaller than normal on MRI. Peripheral branches of the pulmonary vessels do not develop, and vasculature is arrested at the stage at which the infection occurred.

Ultrasonography

Findings

Ultrasound is usually not useful in the assessment of the patient with Swyer-James syndrome.

Nuclear Imaging

Findings

On ventilation-perfusion lung scanning, diminished activity of the affected lung is seen with perfusion scanning, and decreased gas exchange is seen during the ventilatory phase. The lung perfusion deficit seen in patients with Swyer-James syndrome occurs because the peripheral branches of the pulmonary vessels have not developed normally, and vasculature is arrested at the stage at which the causative infection occurred.

False Positives/Negatives

Any disorder involving distal airway obstruction (ie, bronchiolitis obliterans, asthma, congenital lobar emphysema) may present in the same manner as Swyer-James syndrome.

Angiography

Findings

In patients with Swyer-James syndrome, the pulmonary artery and its branches are small and hypoplastic on the involved side. Collateral vessels may be present, but they are unusual.

Degree of Confidence

With angiography, acquired hypoplastic lung cannot be differentiated from congenital hypoplasia of the lung.

False Positives/Negatives

Swyer-James syndrome is similar in appearance to lobar emphysema, congenital hypoplasia of the lung, and hypoplastic pulmonary artery.

Intervention

• Patients should be monitored carefully to avoid severe infections.
• Patients should avoid inhaling injurious substances.
• Patients should avoid smoking, as well as hobbies and occupations in which exacerbating inhalational injury or pulmonary barotrauma may occur.
• Patients should be attentive to air-quality reports.

Multimedia

Media file 1: Anteroposterior chest radiograph of a 12-month-old patient indicates diffuse pneumonia that is clearing on the right.

Media file 2: Radiograph of the same infant shown in Image 1, now 20 months of age. The pneumonia has cleared. The left lung is hyperlucent and is overexpanded. The right lung is small. The patient was asymptomatic at this time.

Media file 3: X-ray of a 4-month-old child shows pneumonia centrally throughout the right lung. Pneumonia was caused by a severe respiratory syncytial virus infection.

Media file 4: Same child shown in image 3, now 8 years of age. The patient was experiencing severe wheezing and episodes of hypoxemia. Note the small right lung and overexpansion of the left lung.

Media file 5: A febrile, ill, 3-month-old infant with rales and rhonchi, which are more severe on the left than the right.

Media file 6: The same patient shown in Image 5, now 12 years of age. Frontal radiograph shows the left lung to be somewhat small and hyperlucent. The organism that caused the original pneumonia was cytomegalovirus.

References

1. Braunschweig M, Gal I. Swyer-James syndrome. JBR-BTR. Apr 2001;84(2):57. [Medline].

2. Chalmers JH Jr. Swyer-James syndrome. Semin Respir Infect. Sep 1999;14(3):295-7. [Medline].

3. Cumming GR, Macpherson RI, Chernick V. Unilateral hyperlucent lung syndrome in children. J Pediatr. Feb 1971;78(2):250-60. [Medline].

4. Khalil KF, Saeed W. Swyer-James-MacLeod Syndrome. J Coll Physicians Surg Pak. Mar 2008;18(3):190-2. [Medline].

5. Gopinath A, Strigun D, Banyopadhyay T. Swyer-James syndrome. Conn Med. Jun-Jul 2005;69(6):325-7. [Medline].

6. Górska L, Kuziemski K, Wajda B, Damps-Konstanska I, Tokarska B, Jassem E. [Hyperlucent lung syndrom caused by pulmonary artery hypoplasia in patient with diagnosed asthma--case report]. Pol Merkur Lekarski. May 2008;24(143):436-8. [Medline].

7. Kiratli PO, Caglar M, Bozkurt MF. Unilateral absence of pulmonary perfusion in Swyer-James syndrome. Clin Nucl Med. Sep 1999;24(9):706-7. [Medline].

8. Lucaya J, Gartner S, Garcia-Pena P. Spectrum of manifestations of Swyer-James-MacLeod syndrome. J Comput Assist Tomogr. Jul-Aug 1998;22(4):592-7. [Medline].

9. Kim CK, Koh JY, Han YS, Kang H, Kim JS, Koh YY. Swyer-James Syndrome with finger clubbing after severe measles infection. Pediatr Int. Jun 2008;50(3):413-5. [Medline].

10. Aleric I, Krpan M, Peros K. Bronchial adenoid cystic carcinoma presenting as unilateral hyperlucent lung (Swyer-James-McLeod syndrome). Wien Klin Wochenschr. 2007;119(23-24):711. [Medline].

11. Ghossain MA, Achkar A, Buy JN. Swyer-James syndrome documented by spiral CT angiography and high resolution inspiratory and expiratory CT: an accurate single modality exploration. J Comput Assist Tomogr. Jul-Aug 1997;21(4):616-8. [Medline].

12. Dornia C, Pfeifer M, Hamer OW. [MacLeod-Swyer-James syndrome--incidental CT finding in a 21-year-old patient]. Rofo. Apr 2008;180(4):351-3. [Medline].

Keywords

Swyer-James syndrome, MacLeod syndrome, hyperlucent lung, hyperlucent thorax, unilateral hyperlucent lung, hypogenetic lung, SJS, pulmonary hyperlucency, pulmonary emphysema

Contributor Information and Disclosures

Author

Beverly P Wood, MD, MS, PhD, Professor, Departments of Radiology and Pediatrics, Division of Medical Education, Keck School of Medicine, University of Southern California
Beverly P Wood, MD, MS, PhD is a member of the following medical societies: American Academy of Pediatrics, American Association for Women Radiologists, American College of Radiology, American Institute of Ultrasound in Medicine, American Medical Association, American Roentgen Ray Society, Association of University Radiologists, Radiological Society of North America, and Society for Pediatric Radiology
Disclosure: Nothing to disclose.

Medical Editor

Lori Lee Barr, MD, FACR, FAIUM, Clinical Associate Professor of Radiology, University of Texas Health Science Center in San Antonio; Clinical Assistant Professor of Radiology, University of Texas Medical Branch at Galveston; Member, Board of Directors, Austin Radiological Association; Consulting Staff, Seton Health Network, Columbia/St David's Healthcare System, Healthsouth Rehabilitation Hospital of Austin, Georgetown Hospital, St Mark's Medical Center, Cedar Park Regional Medical Center
Lori Lee Barr, MD, FACR, FAIUM is a member of the following medical societies: American Association for Women Radiologists, American College of Radiology, American Institute of Ultrasound in Medicine, American Roentgen Ray Society, American Society of Pediatric Neuroradiology, Association of University Radiologists, Radiological Society of North America, Society for Pediatric Radiology, Society of Radiologists in Ultrasound, Southern Medical Association, Texas Radiological Society, and Undersea and Hyperbaric Medical 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

Eugene C Lin, MD, Clinical Assistant Professor of Radiology, University of Washington Medical School
Eugene C Lin, MD is a member of the following medical societies: American College of Nuclear Medicine, American College of Radiology, Radiological Society of North America, and Society of Nuclear Medicine
Disclosure: Nothing to disclose.

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