Study on diagnostic value of analyzing argyrophilic nucleolar organizer regions in benign and malignant pleural effusions

Objective: To evaluate the diagnostic value of argyrophilic nucleolar organizer regions (AgNOR) measurement in benign and malignant pleural effusions.

Methods: Pleural effusions from 50 patients with proven malignant disease, 30 patients with benign disease were studied using the one-step silver staining method. Six cytologically atypical samples were also included in this study.

Results: The mean AgNOR count in malignant cells was significantly higher than that in benign mesothelial cells (7.6 +/- 1.4 vs 2.3 +/- 0.7, P < 0.01). The morphological features of AgNOR in malignant cells were mainly of diffuse type (80%), while in benign mesothelial cells, mainly of nucleolar type (90%). Among the six cytologically atypical samples, four were in the malignant range, two were in the benign limits, and these were proved by histopathology.

Conclusions: AgNOR study may be useful in differential diagnosis of benign and malignant pleural effusions.