Validity of the AgNOR count in cervical pathology

Nucleolar organizer regions (NORs) were counted on ten cases each of normal ectocervix, CIN 1, 2 and 3 to verify the possibility of a differentiation between the various grades of CIN and between them and condylomata. Counts were performed on the full thickness of the tissue, layer by layer (stratified counts). A significant difference (p < 0.05) was found between the means of normal tissue toward condylomata and CIN 2 and 3 and between CIN 1 and CIN 2 and 3. There was no significance (p < 0.05) between normal tissue and CIN 1, between CIN 2 and 3 and between condylomata and CIN 2 and 3. The range of variations on the counts was associated with overlapping between the various cases. Our data showed also a progressive rise in mean NOR values from normal tissue to CIN 3. The stratified counts showed in all the groups a rise from basal to parabasal cells. Counts on parabasal and intermediate layers distinguished two groups of cases. In one there was either the same number of dots or a further rise from one layer to the next, while in the other a definite decrease was seen. The former pattern may be related to a potential for malignant evolution of the lesion. NORs should be counted in all cases of CIN and condylomata to treat more aggressively those lesions which present the pattern of a progressive rise of NORs from basal to intermediate cells.