ABSTRACT
BACKGROUND: Detection of malignant effusion is important task in the routine laboratory work. However, in clinical laboratory where only Wright-Giemsa stained slides are examined it is not easy. So the author proposed a scoring system in the differential diagnosis of malignant effusion using the results of routinely tested items. METHODS: 61 samples of exudates (13 ascites, 48 pleural fluids) from 47 patients were included. The scores are summed based on the routine laboratory results. Items were as follows: protein concentration, dominancy of lymphocyte (lymphocyte count over 50%) and morphologic variety of lymphoid cells, mesothelial cell count, eosinophil count, and presence of tumor cells. Total summed full scores would be 8 points. RESULTS: The summed scores of 14 samples of malignant effusion were as follows: 7 points in 2 cases, 6 points in 1 case, 5 points in 8 cases, 4 points in 3 cases, with the mean score of 5.1 points. The 47 benign exudates showed 4 points in 1 case, 3 points in 4 cases, 2 points in 33 cases, 1 point in 9 cases, with the mean score of 1.9 points. If malignancy were postulated as summed score over 4 points, a statistically significant difference was observed between the summed score and effusion type (P<0.0001). CONCLUSIONS: Two groups of effusion can be distinguished: one group that showed more than 4 points, with malignant potential and the other group lower than 3 points with benign effusion. In case with high score, 4 points above, one should pay attention to the presence of malignant cells and even if tumor cells were not found, the possibility of malignant condition should be notified.