VA Report: Pleural (Fluid) Pearls!

Take Home Point #1: If you see >5% mesothelial cells in the pleural fluid, tuberculosis is unlikely!

Take Home Point #2: Rheumatoid pleurisy is typically associated with a very low pleural fluid glucose level.

Mesothelial cells: If you see greater than 5% mesothelial cells in the pleural fluid, tuberculosis is unlikely!

If you see a low pleural fluid glucose:
–       Rheumatoid pleurisy
–       Complicated parapneumonic effusion or empyema
–       Malignant effusion
–       TB
–       Lupus pleuritis
–       Esophageal rupture

If you see a high pleural fluid amylase:
–       acute pancreatitis
–       chronic pancreatic pleural effusion
–       esophageal rupture
–       malignancy

The evolution of an exudate:

  1. The acute response to any pleural injury (infectious, immunologic, or malignant) is the attraction of neutrophils to the pleural space.
  2. Then, around 72 hours after injury, mononuclear cells enter the pleural space and become the predominant cells.
  3. The macrophage predominance is subsequently replaced by lymphocytes in effusions that persist for >2 weeks.

What does this tell me?

A neutrophil-predominant exudate should be expected when the patients present acutely with a pleural effusion (e.g. acute bacterial pneumonia, acute pulmonary embolism, acute pancreatitis).

Pleural effusions that are subacute or chronic (e.g. TB, malignancy) are associated with a lymphocyte predominance.


Sahn SA. Evaluation of the patient with a pleural effusion. ACCP, PCCSU Article. January 2008.

Light RW, Erozan YS, Ball WC. Cells in pleural fluid: their value in differential diagnosis. Arch Intern Med. 1973;132(6):854-860.

Heffner JE. Diagnostic evaluation of a pleural effusion in adults: initial testing. UpToDate.


One thought on “VA Report: Pleural (Fluid) Pearls!”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s