Pleural fluid analysis for diagnosis of a cholesterol effusion

* If triglycerides and cholesterol were not requested on initial thoracentesis, they can be added on to fluid stored in the laboratory. Occasionally, a repeat thoracentesis will need to be performed to obtain fresh pleural fluid for accurate measurement.
¶ Both chylothorax and cholesterol pleural effusion are possibilities. We generally pursue a diagnosis of chylothorax first (because it is more common) but a parallel investigation for both conditions is also appropriate.