Usefulness of scoring system distinguishing between benign and malignant effusion based on routine laboratory result

Seek, Kim Ae

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.