RESUMEN
Nucleolar organizer regions (NORs) have been identified by means of an argyrophilic technique (AgNOR) in routinely processed formalin-fixed paraffin sections of breast lesions. 85 cases of different breast lesions were examined. The AgNOR counts were, normal breast 1.2 (1.0-1.5) Fibroadenoma 1.74 (1.6-2.7), purely cystic disease 1.6 (1.5-1.82) adenosis 2.1 (1.7-2.8), Epitheliosis 2.4 (1.9-3.2) gynaecomastia 3.7 (3.6-4.7), Noninvasive caccinoma 2.8 (2.6-4.4) invasive carcimomas 3.89 (2.7-9.9) i.e. mean AgNOR counts between benign and malignant lesions. Also gynaecomastia, a benign condition had a high mean AgNOR count. There was no significant difference in the mean AgNOR count of various types of invasive breast caninoma. Higher the histological grade, higher was the AgNOR count. To conclude, AgNOR technique does not enable a clear distinction between benign & malignant lesions. But, it could be used with other prognostic indices to predict the behaviour of breast malignancy.