CHANGES IN THE NUMBER OF SILVER-STAINED NUCLEOLAR ORGANIZER REGIONS IN THE NORMAL, PRENEOPLASTIC, AND NEOPLASTIC ENDOMETRIUM

The number of silver-stained nucleolar proteins (AgNORs) were counted in preneoplastic and neoplastic endometrial lesions and compared with those of the normal endometrium in the menstrual cycle. In glandular c ells in the normal menstrual cycle, the mean number of AgNORs in the p roliferative phase endometrium (3.4) was significantly higher than tha t in the secretory phase endometrium (2.5, p < 0.01). The mean number of AgNORs in well-differentiated endometrioid type adenocarcinoma (4.2 ) was significantly greater than that in simple hyperplasia (3.0, p < 0.001) and complex hyperplasia without cytological atypia (3.6, p < 0. 05). The average number of AgNORs showed an increased tendency accordi ng to the neoplastic changes in the endometrium. These findings sugges t that the one-step colloid method for AgNORs may therefore be a simpl e and partially useful technique for examining the proliferative activ ity in neoplastic and preneoplastic endometrial cells, but no clear di stinction in each preneoplastic and neoplastic endometrial lesion can be drawn so far from our measurements.