A chylothorax refers to the presence of chylous fluid in the pleural space often as a result of obstruction or disruption to the  thoracic duct. It may be congenital or acquired.

Chylothoraces may present with variable pleural fluid appearance and biochemical characteristics; they are usually exudative. A non-milky appearance is common. Chylous effusions can rarely be transudative (especially in patients with cirrhosis).

It can be due to direct injury to the lymphatic ducts or due to obstruction of the ducts and fragile collateral formations which are prone to spontaneous rupture: 

In a neonate:

Location - distribution

The distribution according to one study was 8

  • right: ~50%
  • left: ~33.3%
  • bilateral: ~16.6% 

Increased density of hemithorax with ipsilateral pleural effusion (most common on the left). Less frequently bilateral.

Simple appearing pleural effusion without debris or septations.

Most of the time, it appears as a simple fluid collection of near water density.

Low output (less than 1000mL/day) is treated conservatively with a low-fat diet. High output usually treated with open or video-assisted ligation. Alternatively, thoracic duct embolisation can be performed by an interventional radiologist with a comparable outcome to surgical ligation.

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Article information

rID: 7328
System: Chest
Tag: cases
Synonyms or Alternate Spellings:
  • Chylothoraces

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Cases and figures

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