NUCLEOLAR ORGANIZER REGIONS IN UTERINE CERVICAL-CANCER AND ITS PRECURSOR EPITHELIAL LESIONS

The number of nucleolar organizer regions was assessed in 115 histological samples of uterine cervical carcinoma or precursor epithelial lesions. Normal endocervical or exocervical epithelial tissues were used as controls. Nucleolar organizer regions were stained with colloidal silver in formalin fixed histological samples and quantified in 100 cells, according to Crocker's method. The mean number of nucleolar organizer regions were 13.7 in infiltrative carcinoma, 9.15 in carcinoma in situ, 9.3 in severe dysplasia, 8.4 in moderate dysplasia, 7.5 in mild dysplasia, 6.4 in condylomas and 3.2 and 2.9 in normal exocervical and endocervical epithelia respectively. There were significant differences in the number of nucleolar organizer regions between normal and abnormal tissues and between the different lesions except between moderate and mild dysplasia and between carcinoma in situ and moderate and severe dysplasia. The highest number of nucleolar organizer lesions was always observed in the basal strata of both normal and abnormal tissues. It is concluded that nucleolar organizer regions are a good index of cellular proliferation in uterine epidermoid cervical carcinoma and its precursor lesions, and have a diagnostic value in infiltrative carcinoma.