The Role of Argyrophilic Nucleolar Organizer Region (AgNOR) Study in Cytological Evaluation of Fluids, Especially for Detection of Malignancy

Abstract

BackgroundSerous effusion smears reported as "suspicious for malignancy" pose problems in clinical management. Silver staining for argyrophilic nucleolar organizer regions (AgNOR) has proved useful in making a cytopathologic differential diagnosis between benign and malignant cells. Nucleolar organizer regions(NORs) are loops of DNA located in acrocentric chromosomes. These NORs are visualized by silver staining technique that recognizes these argyrophilia associated proteins which are increased in malignancy. ObjectiveThis study aimed to distinguish reactive mesothelial cells from malignant cells in serous effusions using these NORs. MethodsA total of 174 serous effusions received at the Department of Pathology, TUTH, during a period of one year were included in the study. Smears were studied by conventional Papanicolaou and Giemsa stains. AgNOR counts, variation in size and dispersion of AgNOR dots in smears were graded and compared in malignant and non-malignant effusions. ResultsMean AgNOR counts of 10.43±0.73 and 10.21±0.51 in malignant peritoneal and pleural effusions, respectively, were significantly (p<0.0001) greater as compared with counts of 2.12±0.54 and 2.11±0.54 in non-malignant effusions. The AgNORs were irregular in shape in malignant effusions whereas they were comparatively larger, single dots in benign effusions. AgNOR size and dispersion were of higher grade in significantly greater proportion of malignant as compared with non malignant effusions (p<0.0001). Of the cytologically suspicious samples, nine were in the malignant range and one was in the benign range. ConclusionAgNOR study appears to be clinically useful as an additional diagnostic tool for use in serous effusion when the cytologic diagnosis is difficult.

Diagnostic Efficiency of Cell Block Method over Conventional Smear Method in the Cytology of Malignant Effusions– A Prospective Study

“…Both these values were higher than that obtained by G.G Nair which was 33.56% for cell block method & 14.48% for conventional smear analysis (22) . The most common primary malignancy in the fluid samples was Serous Carcinoma Ovary (33.3%%) in the present study; similar to the studies by Karki S et al (23) , Bjorn et al (24) and…”

Apoptosis and expression of argyrophilic nucleolus organizer regions in epithelial neoplasms of the larynx

“…Karki et al 34 found irregularly shaped AgNORs in malignant cells of pleural and peritoneal effusions, and large and individual AgNORs in benign cells of the same effusions. Arora et al 35 showed that apparently the number of AgNORs per nucleus in patients with SCC of the larynx increases as the degree of tumor dedifferentiation increases.…”

“…Therefore, our findings are similar to those described for cancers of the larynx 35 and for cells of pleural and peritoneal effusions. 34 …”

Novel strategy to diagnose and grade hepatocellular carcinoma

“…AgNORs correlate with the proliferative activity of neoplasms. Increased AgNOR counts may reflect increased proliferative activity of cells [29].…”

“…AgNOR increasingly applied in histopathology research following suggestions that there may be a possible association between high AgNOR counts and malignant transformation [29]. It is interesting to hypothesize, therefore, that the numbers, the shape, and the distribution of AgNORs within the nucleus might be of potential use in predicting behavior in different carcinomas [30].…”