대한흉부영상의학회 Weekly Chest Cases

Case No : 342 Date 2004-05-15

Courtesy of Dong Wook Sung, M.D., Jeong-Hwa Kong, M.D. / Kyunghee University Hospital, Seoul, Korea
Age/Sex 65 / F
Chief ComplaintMild dyspnea (for 15 days)

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Diagnosis With Brief Discussion

Diagnosis: Swyer-James syndrome
Radiologic Findings: Chest PA(Fig.1) shows ill-defined increased opacity on left perihilar region, and slight indistinct of left cardiac border. Mediastinal structures are deviated to left side. There are associated findings of old tuberculosis on left upper lobe, and left apical pleural thickenings.

Chest CT of mediastinal setting (Fig.2-3) shows hypoplastic left pulmonary artery, main and segmental branches. There is marked deviation of heart to left side. CT with lung setting (Fig. 4-5) shows bronchiectasis on left lingular and lower lobes with air trapping. Marked decreased the caliber of left pulmonary artery compared with right side.
Brief Review: Swyer-James syndrome is known by several names including MacLeod syndrome, unilateral hyperlucent lung, unilateral bronchiolitis obliterans, and unilateral emphysema. The syndrome is characterized by unilateral hyperlucency with associated decrease in the size and number of pulmonary vessels on the involved side. It is a variant of post-infectious bronchiolitis obliterans that is most commonly the sequelae of a viral infection during infancy or early childhood. There is a necrotizing bronchiolitis (bronchiolitis obliterans) which damages the terminal and respiratory bronchioles and prevents the normal development of their alveolar buds. Additionally, fibrosis (the result of the healing process) results in bronchiolar obstruction that in turn leads to air trapping.

Patients may be asymptomatic, or complain of recurrent URI's or dyspnea on exertion. Although classically involving an entire lung, the disorder can be lobar or subsegmental.

On Chest PA, there is unilateral hyperlucency with a small pulmonary artery and decreased vascularity on the affected side. There is a prune tree appearance to peripheral bronchi. On CT, there are hyperlucent regions without surrounding walls (cysts and bulla have walls) and the central pulmonary artery is small with decreased branching and sparse vessels within the hyperlucent region. Expiratory scans demonstrate air trapping in the involved areas. Bronchiectasis is not necessarily a component of the disorder, although it is frequently seen in the affected lung. The presence of saccular bronchiectasis has been reported to be associated with an increased risk for recurrent infection. On ventilation scintigraphy with xenon there is air trapping with delayed wash-in and washout from the involved areas. Matching perfusion defects are identified.

Differential considerations for a unilateral hyperlucent lung include: endobronchial foreign body, pneumothorax, congenital lobar emphysema, pulmonary artery hypoplasia/occlusion (no air trapping evident on expiratory images), compensatory hyperinflation, or chest wall defect (Polland's syndrome).
References
Keywords: Lung, etc, Sequelae of previous inflammation,

No. of Applicants : 30

▶ Correct Answer : 23/30, 76.7%

- AZ Vesalius Hospital, Tongeren, Belgium Maes Bart
- Centre d'imagerie Jacques Callot, Nancy, France Lionel Cannard
- Cheongju saint Mary Hospital, Cheongju, Korea Jeong Geun Yi
- CHU Nancy-Brabois, France Denis Regent
- CIM Saint Dizier, France JC Leclerc
- Eulji hospital, Korea Jeong Joo Woo
- Geneva University Hospitals, Switzerland A.B. Younossian
- Hangang SacredHeart Hospital, Korea Eil Seong Lee
- Hanyang University Hospital, Seoul, Korea Yo Won Choi
- Incheon Sarang Hospital, Korea Jung Hee Kim
- Kangbuk Samsung Hospital, Korea Hyon Joo Kwag
- Kocaeli medical school, Turkey Salih Topcu
- Mallinckrodt Institute of Radiology, USA Jin Mo Goo
- National Taiwan University Hospital, Taiwan Tan Che Kim
- National Taiwan University Hospital, Taiwan Sheng-Hsiang Lin
- Pusan National University Hospital, Korea Woon-Jung Kwon
- Royal Melbourne Hospital, Melbourne, Australia Stefan Heinze
- Samsung Medical Center, Korea Semin Chong
- Samsung Medical Center, Korea Sung Shine Shim
- Sharma Clinic, Jaipur, India Dinesh Sharma
- Shinsegae Rad Clinic Gi Beom Kim
- Social Security Hospital, Ankara, Turkey Meric Tuzun
- UNIFESP-EPM and Fleury Medical Center, Brazil Gustavo Meirelles

▶ Semi-Correct Answer : 4/30, 13.3%

- Annecy Hospital, France Gilles Genin
- Dong-A University Hospital, Korea Ki-Nam Lee
- Homs National Hospital, Homs, Syria Rami Abou Zalaf
- Ondokuz Mayis University, Samsun, Turkey Cetin Celenk

대한흉부영상의학회 Korean Society of Thoracic Radiology

Archive of Old Cases

Case No : 342 Date 2004-05-15

Discussion

No. of Applicants : 30