Encysted pleural fluid

Case contributed by Dr Chris Lim


Acute myeloid leukaemia. Recent fluid overload with large right-sided pleural effusion. Chest x-ray performed as part of septic screen in the context of neutropenic fever.

Patient Data

Age: 55 years
Gender: Male

Ovoid shaped density at the posterior mid chest, most in keeping with pleural fluid encysted within the right oblique fissure, especially in the context of a previous large right pleural effusion seen on CTPA performed two weeks prior. 

Patchy airspace opacities on the left with some minor changes persisting at the mid and lower zones.

Cardiomediastinal contours are within normal limits. Right Hickman catheter has its tip at the cavoatrial junction.  No pneumothorax or free subdiaphragmatic gas.

Case Discussion

Pleural pseudotumors refer to encysted focal pleural fluid collections located within a lung fissure, and often appear as lenticular or biconvex shaped opacities on plain radiographs. This radiograph was performed as part of a septic screen in the context of neutropenic fever and recent fluid overload.

A CT pulmonary angiogram performed two weeks prior demonstrated a large right pleural effusion, small left pleural effusion, large pericardial effusion, and bilateral patchy centrilobular consolidation: appearances consistent with fluid overload, but potentially also explained by pericarditis or atypical pulmonary infection.

A chest x-ray performed two weeks prior demonstrated a large right sided pleural effusion but no evidence of encysted pleural fluid.

In this context, the above findings were thought to most likely represent a pleural pseudotumor due to the recent history of fluid overload. Differential diagnoses included pleural infection or pleural-based mass. The acute nature of its appearance (within two weeks) makes malignancy less likely.

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Case information

rID: 69257
Published: 4th Jul 2019
Last edited: 14th Aug 2019
System: Chest
Inclusion in quiz mode: Included
Excluded from licensing

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