Silver stained Nucleolar organizer regions in nonneoplastic and neoplastic lesions of endometrium

Nucleolar organizer regions (NORs) are loops of DNA that transcribe to ribosomal RNA. They are associated with nonhistone nucleoproteins which can be stained with silver (AgNORs). The present retrospective study was done to study the efficacy of AgNOR technique in differentiating between non neoplastic and neoplastic lesions of endometrium and to assess the relationship between AgNOR counts and severity of hyperplasia and carcinoma. This study was carried out in the Department of Pathology, in a tertiary care teaching hospital from July 2009 to August 2011. Endometrial specimens received were processed and stained with H & E and AgNOR. Mean AgNOR counts were correlated with histopathological diagnosis. In results out of 100 cases of endometrial specimens studied, 40 were normal endometria (proliferative and secretory phase), 41 were nonneoplastic lesions (simple hyperplasia without atypia, complex hyperplasia without atypia, complex hyperplasia with atypia) and rest 19 were neoplastic lesions (Grade 1 and Grade 2 endometrioid adenocarcinomas). Significantly higher mean AgNOR counts were found in endometrial adenocarcinomas as compared to all hyperplasias and higher in hyperplasias as compared to normal proliferative phase and least in normal secretory phase. In conclusion AgNOR counts are reliable markers of endometrial proliferation and allow a clear distinction between normal, non neoplastic and neoplastic endometrial changes. Thus, AgNOR technique proves to be a useful adjunct to routine histopathology to evaluate endometrial lesions.