round atelectasis

nicht verwechseln mit: Rundpneumonie

Round atelectasis, also known as rounded atelectasisfolded lung or Blesovsky syndrome, is an unusual type of lung atelectasis where there is infolding of a redundant pleura. The way the lung collapses can at times give a false mass-like appearance.


Two theories have been put forward. The second theory is more favored while the multi-factorial etiology suggests both mechanisms probably operate in different patients:

  • Hanke and Kretzschmar
    • underlying pleural effusion causes local atelectasis in the adjacent lung
    • a cleft or infolding of the visceral pleura will then form if the rate of pleural fluid formation exceeds alveolar air absorption
    • this then causes the lung to tilt on the cleft
    • the lung then curls on itself in a concentric fashion
    • fibrous adhesions suspending the atelectatic segment (and usually tilt the lung cranially) develop
    • as the effusion resorbs, the aerated lung fills in the space between the area of round atelectasis
    • organization of the fibrinous exudate and fibrous contraction lead to additional lung parenchymal distortion
  • Schneider et al. (expanded on by Dernevik and colleagues)
    • a local pleuritis caused by irritants such as asbestos
    • in the event of a benign asbestos-related pleural effusion, the pleura contracts and thickens with shrinkage of the underlying lung, and atelectasis develops in a round configuration

It can be associated with:


There may be a predilection towards the lower lobes .

Radiographic features

  • round or oval in shape 
  • almost always seen adjacent to a pleural surface
  • there is associated adjacent pleural abnormality, e.g. pleural thickening or pleural effusion
  • comet tail sign : produced by the pulling of bronchovascular bundles giving the shape of a comet tail
  • crow feet sign
  • as it represents collapsed lung, it commonly demonstrates a typical parenchymal enhancement 
  • posterior lower lobes are most commonly involved and, sometimes, bilateral or symmetrical

Rounded atelectasis can occasionally increase in size on serial scans .

Nuclear medicine
  • not metabolically active
  • may play a role in differentiating from malignancy when there are few or atypical features on chest radiographs and CT

History and etymology

It was first described by Loeschke in 1928 .

See also

Siehe auch:
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