SILVER-STAINED NUCLEOLAR ORGANIZER REGIONS IN THE UTERINE MYOMATOUS TUMORS

The numbers of silver-stained nucleolar organizer regions (AgNORs) wer e counted in uterine myomatous tumors, and compared with those in corr esponding normal myometria. The mean number of AgNORs in myomatous tum ors tended to increase according to the neoplastic changes. The mean n umber of AgNORs in leiomyosarcoma (6.4 +/- 0.9) was significantly high er than that in cellular leiomyoma (4.5 +/- 0.7, P < 0.01) or leiomyom a (3.0 +/- 0.5, P < 0.001), In the normal myometria, the mean number o f AgNORs (3.3 +/- 0.4) in the premenopausal women showed a higher tend ency than that in the postmenopausal women (2.4 +/- 0.5). These result s therefore suggest that AgNOR counts may be useful for diagnosis of c ellular activity in uterine myomatous tumors.