Morphometric evaluation of nucleolar organiser regions in reactive and neoplastic lymph node lesions

Argyrophilic nucleolar organiser regions (AgNORs) have widely been used for making diagnostic as well as prognostic statements in neoplastic lesions. The present study was aimed at the quantitative and morphometric analysis of AgNORs in various lesions of lymph node. Thirty cases consisting 10 cases each of reactive lymphadenitis, non-Hodgkin's lymphoma (NHL) and metastatic deposits from carcinoma breast were included in the present study. Out of the ten cases of NHL, there were four cases of low grade and six cases of high grade lymphoma. The quantification of AgNOR dots and their morphometric evaluation were done using a specific programme of an automatic image analyser. The results revealed that mean AgNOR count was maximum in metastatic lymph nodes (5.37 +/- 0.35) when compared with NHL (high grade 5.12 +/- 0.27; low grade 4.61 +/- 0.13) and reactive lymphadenitis (2.45 +/- 0.49). The mean area of single AgNOR dot in metastatic lymph node, high grade lymphoma, low grade lymphoma and reactive lymphadenitis were 123.3 +/- 26.1, 95.3 +/- 12.2, 99.6 +/- 6.53 and 87.4 +/- 8.45 respectively. Similarly, the mean of total AgNOR area in metastatic lymph nodes was highest (668.4 +/- 169.9) followed by NHL (high grade 496.35 +/- 53.2; low grade 459.25 +/- 37.35) and reactive lymph node (215.0 +/- 37). However, the ratio of single AgNOR area to nuclear area was maximum in reactive lymphadenitis (0.132 +/- 0.001) followed by low grade NHL (0.083 +/- 0.0096), high grade NHL (0.073 +/- 0.0098) and metastatic lymph nodes (0.064 +/- 0.001). The ratio of total AgNOR area to nuclear area was also minimum in reactive lymph node when compared with other neoplastic lesions. Statistically, the p-value revealed a highly significant difference among all these lesions. Thus, it can be concluded from the present study that AgNOR count and other morphometric parameters are significantly altered in different lesions of lymph node which may aid in differentiation of problematic cases.