Related Experiment Video
Updated: Aug 9, 2026
In vitro Mesothelial Clearance Assay that Models the Early Steps of Ovarian Cancer Metastasis
Published on: February 17, 2012
Evaluation of AgNOR count in distinguishing benign from malignant mesothelial cells in pleural fluids
1Department of Pathology, Ospedale Maggiore Lodi, Italy.
Insights
This study found that counting intranuclear dots, known as nucleolar organizer regions-AgNORs, can help distinguish between benign reactive and malignant mesotheliomatous pleural effusions. Higher AgNOR counts indicate malignancy, aiding in diagnosis.
Area of Science:
- Cytopathology
- Oncology
- Biomarker Discovery
Background:
- Distinguishing benign reactive from malignant pleural effusions is crucial for patient management.
- Nucleolar organizer regions (NORs) are associated with cell proliferation and can be visualized as intranuclear dots (AgNORs).
Purpose of the Study:
- To evaluate the diagnostic utility of interphase nucleolar organizer regions-stained AgNORs in differentiating reactive and malignant pleural effusions.
- To assess the quantitative differences in AgNOR counts between these two conditions.
Main Methods:
- AgNOR staining technique was applied to eight reactive and eight malignant pleural effusions.
- Intranuclear AgNOR counts were quantified per nucleus.
- Statistical analysis using the Mann-Whitney U Wilcoxon Rank Sum W Test was performed.
- Automatic image analysis was used to evaluate AgNOR area and morphology variations.
Main Results:
- Mean AgNOR count in benign reactive effusions was 1.56 (SD 0.77).
- Mean AgNOR count in mesotheliomatous effusions was 2.81 (SD 1.44).
- A statistically significant difference in AgNOR counts was observed between the two groups (p<0.05).
Conclusions:
- AgNOR counting is a valuable method for differentiating reactive from malignant pleural effusions.
- Increased AgNOR counts are indicative of malignancy in pleural fluid cytology.
- Further studies can explore AgNOR morphology and area for enhanced diagnostic accuracy.
Abstract:
The authors have evaluated in eight reactive and eight malignant pleural effusions the number of intranuclear dots representing the nucleolar associated proteins stained with silver colloid technique (interphase nucleolar organizer regions-AgNORs). The mean number per nucleus in benign reactive effusions was 1.56 (SD 0.77) while in mesotheliomatous effusions it was 2.81 (SD 1.44). The statistical analysis of values, by Mann-Whitney U Wilcoxon Rank Sum W Test, revealed a significant difference of AgNOR counts in the two cytological samples. The variability of AgNOR areas and morphologies in reactive and mesotheliomatous nuclei in pleural fluids is evaluated applying automatic image analysis.
