Nucleoli and nucleolar ribonucleic acid in nonmalignant and malignant human endometria

Analysis of nucleoli in nonmalignant and malignant human endometria in relation to histological grades of malignancy showed, with increased grade of malignancy, more multiple nucleoli, larger size of single nucleoli per nucleus, and greater morphological variations. These nucleolar alterations imply an augmentation of nucleolar activity with increased grade of malignancy. Statistically significant differences were shown for mean diameters of single nucleoli between all groups except Grades I and II. From this biometric study of nucleolar populations, the conclusion seems justified that nucleolar measurements and counts may be of value as aids in the diagnosis between nonmalignant and low-grade endometrial tumors. Such observations may be of clinical value in serving as more valid criteria in the establishment of the histological grade of malignancy and therefore as a better basis for selection of therapy and for prognosis. In addition, from this and other investigations, the evidence lends credence to the idea that increase in RNA and nucleolar activity between benign tissues of origin and malignant tissues may represent a criterion of malignancy and that nucleolar studies may provide a significant index of the lethality of malignant gynecological tumors.