Silver staining method for nucleolar organizer regions in cervical smears.

The distribution of nucleolar organizer regions (NORs) was studied in Papanicolaou preparations of cervical smears in order to distinguish benign from preneoplastic lesions. Destained smears (six defined as normal, six as inflammatory with squamous metaplasia, six as CIN I, six as CIN II, and five as CIN III) were submitted to the Ag-NOR method after staining with Orange G and EA36. Ag-NOR count was performed in previously outlined fields on the smears. Statistically significant differences (P < .05) were found between the normal smears, inflammatory smears with squamous metaplasia, and each grade of CIN. We conclude that the Ag-NOR technique could be useful to evaluate cervical smears of doubtful interpretation, using previous demarcation of the abnormal fields/cells.