Finding the right tests…
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Emergency services available 24 x 7
Finding the right tests…
Biochemistry
Routine and microscopic examination of pericardial fluid looks at what the fluid contains under a microscope — cell counts, cell types, and any abnormal or malignant cells — after fluid is drawn from around the heart, usually because an effusion is large or its cause isn't clear from imaging. The cell pattern found points doctors in different directions: neutrophils with a low glucose level suggest bacterial infection, while cytology showing malignant cells can confirm cancer, something imaging often can't do. In one large series, cytology identified malignant cells with a sensitivity of over 92%, notably higher than pericardial biopsy in the same comparison. This makes fluid microscopy one of the more direct ways to find out what's causing an effusion.
This test examines pericardial fluid directly under a microscope after it's been drawn from around the heart, looking at cell counts, the types of cells present, and their appearance. A lab technician or pathologist checks whether the fluid is dominated by particular white blood cell types, which points toward infection or inflammation, or contains atypical and malignant cells, which points toward cancer. The findings are usually combined with the fluid's chemistry results and, where relevant, cultures for infection.
Different causes of pericardial effusion tend to produce different cell patterns in the fluid. A high neutrophil count alongside a low fluid-to-blood glucose ratio is typical of bacterial infection, while tuberculous pericarditis often shows a thick, caseous fluid with a different cell mix. These patterns give an early clue about the likely cause before other results, like cultures, come back.
When cancer is suspected, cytology — examining the fluid's cells for malignant changes — is the recommended test. In a series of 574 pericardial fluid specimens using a standardised reporting system, roughly a fifth showed clearly malignant cells, with lung and breast cancer the most common sources. Cytology has also been found more sensitive than pericardial biopsy for catching malignancy here.
Routine and microscopic examination is usually paired with the fluid's chemistry results, since no single finding tells the whole story alone. A purulent fluid packed with neutrophils points strongly toward bacterial infection, but confirming that usually still needs culture results too.
Some samples come back with atypical cells that aren't clearly benign or malignant. In these cases, doctors often repeat the analysis, add tests such as flow cytometry, or follow the patient clinically rather than relying on one inconclusive result.
It looks at the fluid's cell counts, the types of white blood cells present, and whether any cells appear abnormal or malignant under the microscope. This pattern helps point toward infection, inflammation, or cancer as the cause of the fluid.
In one large series, cytology identified malignant cells in pericardial fluid with a sensitivity of over 92%, higher than pericardial biopsy in the same comparison. It's one of the more reliable ways to confirm cancer as the cause of an effusion.
It gives strong early clues — a high neutrophil count with low fluid glucose is typical of bacterial infection — but confirming the specific organism usually still needs fluid culture. The two are normally done together.
This page is general information about the test, not medical advice. Your own report's reference ranges apply — please discuss your results with your doctor.
Sometimes cells look atypical without being clearly benign or malignant. In that case, doctors may repeat the analysis, add further tests such as flow cytometry, or continue monitoring the patient clinically.
No, they're different tests run on the same sample. Routine and microscopic examination looks at cell counts and appearance, while ADA measures a specific enzyme linked to tuberculous inflammation.
It's usually collected during pericardiocentesis, a procedure where a needle is used to drain fluid from around the heart, guided by imaging to avoid injury to nearby structures. Ask your doctor about how the procedure will be done in your case.