Multiple Answers:

1. Swyer-James Syndrome of the Right Lung
2. Small right apical pneumothorax

Swyer-James Syndrome

• aka Swyer-James-Macleod Syndrome, Bret Syndrome, hyperlucent-lung syndrome

• a rare condition typically involving unilateral, lobar or even segmental hypoplasia of the pulmonary vasculature with air-trapping and +/- bronchiectasis

• Classically the result of postinfectious obliterative bronchiolitis from viral infection or Mycoplasma pneumoniae infection in early childhood

Radiology

Plain Films

• Hyperlucent lung can be entire lung, lobar or smaller, with dimished vasculature.
• Air-trapping on expiration

CT

• Better visualization air-trapping (hyperlucent lung parenchyma) with decreased vascularity
• Involves entire lung or even can be patchy subsegmental distribution
• Typically, areas of involvement are smaller in volume than the normal lung -> decreased size of that hemithorax
• +/- bronchiectasis/bronchial wall thickening

Nuclear Medicine

• Photopenic areas on V/Q imaging

MRI

• Generally not good at lung parenchyma evaluation
• Can show a small pulmonary artery and fewer peripheral arteries

Prognosis/Treatment

• Generally very good prognosis. Commonly diagnosed incidentally later in life
• This can predispose to recurrent infections
• Controversy over whether steroid use is helpful

Our Patient

While the right hemithorax is not necessarily smaller than the left, it is definitely hyperlucent. And note the signficiantly diminished vascular markings on the right versus the left.

Oh yeah, and there is just happens to be an irregularly shaped (versus multiple) lucency in the right pulmonary apex. Bullae? Scarring? Pneumothorax?

CT from the same patient shows:

1. Hyperlucent areas throughout the right lung, especially the RUL (axials - top row) and posterior RLL (coronals - bottom row)
2. Bronchiectasis and bronchial wall thickening most prominent in the RUL
3. Diminished vascularity throughout much of the right lung when compared to the left
4. Definite pleural air (ie pneumothorax) in the right pulmonary apex with areas of scarring extending from the visceral to parietal pleura. Could this be chronic?

While our patient may not demonstrate the classic "small" lung, it does show the unilateral hyperlucent lung (CXR) and regional areas of hyperlucency/air-trapping with associated dimished vascularity and bronchiectasis consistent with Swyer-James Syndrome.

Oh yeah, and a right apical pneumothorax!

Do you want to see additional causes of Unilateral Hyperlucent lung?

Check out:

Season 10 Case 6

The Chest X-ray game. Same finding. Can you find the cause on each?

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