Nucleolar organizer regions in neoplastic and non-neoplastic epithelium of the cervix.

Argyrophilic nucleolar organizer regions (Ag NORs) were counted in biopsies from 203 cases of various lesions of the cervix. The mean number of Ag NORs per nucleus was significantly higher in CIN (4.05 +/- 0.04) and malignancy (5.50 +/- 0.65) as compared to squamous metaplasia (1.74 +/- 0.32) and chronic cervicitis (1.54 +/- 0.42). Adenocarcinomas had higher Ag NOR counts compared to other carcinomas. Estimation of Ag NORs can be helpful in distinguishing benign lesions from CIN and malignancy of the cervix.