Extrapleural sign

The extrapleural sign, described by Ben Felson in 1973 1, refers to the appearance of a pulmonary opacity with oblique margins that taper slowly to the chest wall when the lesion is viewed tangentially to the x-ray beam. This appearance suggests that the lesion is extrapleural in nature, as opposed to intrapulmonary where an acute angle would be expected as the lesion meets the lung periphery. This term may be confused with extrapleural air sign which refers to a different finding.

Chest x-ray
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Article information

rID: 25564
System: Chest
Section: Signs
Tags: stub, cases
Synonyms or Alternate Spellings:

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