Nucleolar organizer regions (NORs) in normal and pathological liver: a quantitative analysis.

By means of a silver staining method, Nucleolar Organizer Region-associated proteins (NORs) have been evaluated on paraffin sections of a series of 58 ultrasound-guided liver biopsy specimens. These included 12 normal livers, 12 cirrhotic livers, 12 cases of chronic hepatitis and 22 cases of hepatocellular carcinoma. A significant difference (P less than 0.001) was found between the mean AgNOR scores of the normal and pathological biopsies, and between the non-neoplastic and the carcinomatous lesions. The authors suggest that AgNOR counts, in combination with conventional histocytological criteria, may be a useful method in the diagnosis of liver diseases.