Angel wing sign

Case contributed by Dr Asef Zahed


A child with respiratory distress after elective surgery for a tracheocutaneous fistula.

Patient Data

Age: 3 years
Gender: Male


Frontal radiograph showing the most life-threatening finding of right-sided tension pneumothorax with left-sided mediastinal shift; this should be immediately decompressed. Extensive left-sided subcutaneous emphysema is also featured. However, another pertinent finding is of a well-defined structure over the left hemithorax midzone which appears to be 'lifted' off the left heart border. This is the angel wing or spinnaker sign representing the pediatric thymus in pneumomediastinum. 

Nasoenteric tube is correctly placed in the stomach. 

Annotated image

Same frontal radiograph highlighting the angel wing thymus (blue lining) lifted off the left heart border (red lining) 

Case Discussion

Certain plain radiographic signs of pediatric pneumomediastinum are unique compared to adults:

  • air can lift the relatively large thymus gland off from the heart border to give the angel wing or spinnaker sign
  • another sign is air inferior to the mediastinum/superior to the diaphragmatic central tendon which can give the heart a conical appearance described as the Haystack sign after Monet's painting of the same name

These signs are important to be aware of in the young patient as pediatric pneumomediastinum can be otherwise occult.

This case represents an iatrogenic etiology but a careful review of the case is usually required when there is no history of surgical intervention to establish a differential (e.g. infection, esophageal perforation, etc).

The spinnaker or angel wing sign should also not be confused with the thymic sail sign which refers to the pointy/triangular inferior edge of the thymus in normal cases. 

PlayAdd to Share

Case information

rID: 75649
Published: 5th Apr 2020
Last edited: 5th Apr 2020
System: Paediatrics
Inclusion in quiz mode: Included
Institution: Newcastle Upon Tyne NHS Foundation Trust