Massive Left-Sided Pleural Effusion

Author: V. Dimov, M.D.
Reviewer: S. Randhawa, M.D.

A 57-year-old African American male (AAM) is admitted to the hospital with a chief complaint (CC) of shortness of breath (SOB) for 2 weeks. The CXR shows a large left-side pleural effusion.

Massive left sided pleural effusion (click to enlarge the images).

CXR report findings: The lower two-thirds of the left chest is completely opacified probably due to a large pleural effusion. There is LLL atelectasis. The right lung is clear. The pulmonary vascularity is normal. The cardiac silhouette is not well seen.

Impression: Large left pleural effusion with LLL atelectasis. Follow up to complete resolution is necessary.

Would you check additional views in pleural effusion?

Yes. A lateral decubitus film was done.

Lateral decubitus film shows layering of the pleural effusion (click to enlarge the images). The decubitus film is important for two reasons. First, it shows the size of the effusion - if the fluid layer is more than 1 cm, there is enough of it to do a pleural tap. Second, the decubitus film can reveal any loculations in the effusion which make the tap more difficult and are indication for a CT-guided thoracocentesis.

Lateral decubitus CXR report: Findings: Lateral decubitus views of the chest show near complete opacification of the left chest. The right chest appears clear. Compared to the upright PA view there appears to be layering of the left pleural effusion although due to the massive volume the meniscus is not well seen.

Impression: Huge left pleural effusion.

What would you do?

The patients needs a thoracentesis.

What happened?

A pleural tap was attempted but was unsuccessful and a CT-guided thoracocentesis was done.
The procedure was performed in the radiology department under local anesthesia. Under sterile conditions and CT guidance, a 10 French pigtail catheter was introduced into the left pleural space. A total of approximately 2.8 L of amber-colored fluid was drained. Specimens were forward to the lab for analysis as requested. The patient tolerated the procedure well and no immediate complications were noted. There was no sign of pneumothorax following the aspiration.

CBC and CMP (left). Effusion fluid analysis (right) (click to enlarge the images).

How do you distinguish between exudate and transudate?

By using the classic Light's criteria for exudate - look at 3 values. An exudate has one or more of the following characteristics:

Pleural fluid serum protein ratio more than 0.5.
7.2 / 8.2 = 0.87 (our case)

Pleural fluid serum LDH ratio more than 0.6.
576 / 228 = 2.52

Pleural fluid LDH more than two thirds of normal serum value.

New simplified criteria:
Pleural fluid LDH more than 0.45 of the upper limit of normal serum values.

Pleural fluid cholesterol more than 45 mg/dL.
Not measured

Pleural fluid protein more than 2.9 g/dL.

Anibiotic treatment (click to enlarge the images).

What happened next?

The cytology of pleural fluid was negative for malignant cells. The patient improved with antibiotic therapy. Blood, sputum and pleural fluid cultures were all negative. He required one more thoracentesis and after that was discharged home with oral antibiotic therapy. The patient is scheduled to see his primary care physician in 2 weeks and will have a follow-up CXR in 3 months.

Final diagnosis

Massive Left-Sided Pleural Effusion due to Pneumonia.

Using ultrasonography to identify a site for diagnostic thoracentesis is associated with significantly lower risk of pneumothorax, than using the physical exam for site selection.


Pleural Effusion. eMedicine.
Diagnostic Approach to Pleural Effusion in Adults. Am Fam Phys, Vol. 73 No. 5, April 1, 2006.
Pleural effusions: evaluation and management. CCJM, 2005 (PDF).
Pleural effusion from Oxford handbook of clinical medicine By Murray Longmore, Ian B. Wilkinson, Supraj R. Rajagopalan.

Published: 04/11/2005
Updated: 03/09/2009


  1. I would like to know if the scar of a pulmonary parahilar could be removed. It had been 11 years since the patient was diagnosed with pleural effusion and underwent procedure to remove mucus on the affected area. If so, how long will it take to completely remove the scar and what are the medicines to be taken.

    1. Sorry, but I don't think the scar can be removed, it can lead to be COPD, is it right?

  2. i would just want to know if this massive pleural effusion could lead to a lung cancer..
    is it possible?

    1. i think f pleural effusion is due to bacterial infection or due to tuberculosis it can't lead to lung cancer.

  3. Rodelyn,

    A pleural effusion does not lead to lung cancer.

    Lung cancer can lead to a pleural effusion.

  4. how did you jump to the conclusion of Pneumonia as the cause of the effusion??

  5. Ahmed T.,

    Cytology was negative and he improved with antibiotic therapy. Pleural fluid was exudate which made the diagnosis of CHF unlikely. There was no "jumping to conclusion."

  6. may be it is worthwhile including ADA as well in the pleural fluid profile in view of the ethnic background. tuberculosis very commonly presents as large effusion.

  7. Re: "may be it is worthwhile including ADA as well in the pleural fluid profile"

    Not sure if this is warranted as part of the initial workup unless there is a clinical suspicion of TB....


    Tube 1: LDH, protein, amylase, triglyceride, glucose
    (10 mL).
    Tube 2: Gram stain, C&S, AFB, fungal C&S (20-60
    mL, heparinized).
    Tube 3: Cell count and differential (5-10 mL, EDTA).

    Syringe: pH (2 mL collected anaerobically,
    heparinized on ice).

    Bag or Bottle: Cytology.

    Source: Medicine, 2007 Edition, Paul D. Chan, MD, Peter J. Winkle, MD, Current Clinical Strategies Publishing.

  8. We frequently see pleural effusions with TB in immunodeficient patients in South Africa. In fact, very often a pleural effusion in the setting of HIV and weight loss or pyrexia is treated empirically with TB Rx. Response confirms diagnosis.