Diagnostic value of cytologic investigation of cell count differential of pleural fluid

The cell count differential of pleural fluid sample is of great importance for estimation of the nature of pleural effusion. In the present article, we compared the efficiencies of routine cytology method with light microscopy, cytological examination with centrifuge Cytospin-4 and immunocytochemical methods. We have studied cytological samples from 1597 patients, with pleural effusion. Effusions associated with malignancies were reported in 22.7 % of patients including carcinomatosis (74.6 %), primary tumors of pleura (21.5 %), effusions associated with non epithelial malignancies (3.9 %). Benign pleural effusions were reactive (63.6 %), tuberculotic (13.5 %), "cholesterol pleurisy" and chylothorax (0.2 %). Carcinomatous pleuritis was found in patients with lung carcinoma (55.4 %), breast cancer (21.8 %) and ovary cancer (12.2 %). Specific malignant features (direct and indirect) were noted in pleural fluid on breast cancer, carcinomas of ovary, stomach, kidney, small cell lung carcinoma and squamous cell lung carcinoma. These features are hardly detected in patients with malignancies of intestines, prostate and endometria because these types of tumours are rarely metastatic to pleura. We were failed to define particular features of lung adenocarcinoma. The centrifuge Cytospin-4 was used in the most difficult cases (13.5 %) providing minimal number of presumable diagnosis. Primary tumours of pleura are the most difficult for detection. Immunocytochemical analysis found monoclonal mesothelial cell of НВЕМ 1 clone, cytokeratin, vimentin to be positive and carcinoembry onic antigen, Ber-EP4, CD-15 to be negative in the studied tumors.