Sensitivity and specificity of cytodiagnosis of body fluids in a laboratory of urgencies

The main purpose for studying cytological body fluids is confirmation of a benign or malignant effusion. Our cytology laboratory analyzes body fluids and results are requested urgently. The samples are stained by the Giemsa and Papanicolaou methods to give a preliminary report, then they are examined by other complementary techniques. Three hundred thirty samples of pleural and peritoneal fluids were studied to compare the sensitivity of Papanicolaou and Giemsa stains. AgNOR assay, immunocytochemistry and assessment of ploidy were used to improve the sensitivity of the cytodiagnosis. Two hundred one samples were positive, 84 negative and 45 inconclusive using the Papanicolaou stain, while 135 samples were positive, 72 negative and 123 inconclusive using Giemsa stain. The sensitivity was 79%, 53% and 83% for Papanicolaou, Giemsa, and both techniques together, respectively. Using complementary techniques, the sensitivity reached 95% for AgNOR, 87% for tumor markers (panel), and 92% for Ploidy. There were no false positive in our series; therefore specificity was 100%. The use of both Papanicolaou and Giemsa in conjunction increased the sensitivity of the cytodiagnosis in body fluids. The complementary methods, especially AgNOR assay and assessment of ploidy, diminished the number of inconclusive cases.