Abstract
Objective: We assessed the diagnostic value of argyrophilic nucleolar organizer regions (AgNORs) staining to distinguish adenocarcinoma cells (AC), malignant mesothelioma cells (MM) and reactive mesothelial cells (RM) in serous effusions.
Study Design: Aspirated samples of serous effusions from AC (44 cases), MM (10 cases) and benign cause (45cases) were studied using one-step silver staining method for AgNOR proteins. AgNORs were counted in 200 cells, excluding lymphocytes, neutrophils and macrophages, from each sample. All black dots within the nucleus were counted. Dots within nucleoli or aggregated clusters were treated as one AgNOR. The following AgNOR counting parameters were evaluated: 1) the mean number of AgNORs per nucleus (mAgNOR), and 2) the percentages of nuclei with≥2, ≥3, ≥4, and≥5 AgNORs (pAgNOR≥2, ≥3, ≥4, and≥5, respectively).
Results: The mAgNOR of AC (4.08±0.71) was significantly higher than those of RM (2.34±0.30) and MM (2.59±0.59). The mean percentage for pAgNOR≥5 of AC (34.6±17.1) was significantly higher than those of RM (3.6±3.2) and MM (5.9±7.5). There was no significant difference in each parameter between RM and MM.
Conclusion: AgNOR study appears to be useful in differential diagnosis of AC from RM or MM in serous effusions.
