Study of borderline and invasive mucinous ovarian tumors using Ki-67 (MIB 1) antibodies and nucleolar organizer region (NOR) staining

Extensive application of new methods in histopathology has resulted in larg e quantities off data on molecular markers in different types of human tumo rs. The main purpose has been to obtain additional parameters for the chara cterization of various types of malignancy to give more precise information on their biological behavior. In this study we tested AgNOR and Ki-67 (MIB 1) staining in 39 ovarian mucinous tumors to evaluate its diagnostic potent ial in distinguishing between borderline tumors and well-differentiated car cinomas at stage I of FIGO classification. In general, there was an increas e in AgNOR median values from benign (1.83 +/- 0.8) to well-differentiated carcinomas (2.91 +/- 1.3) with an intermediate value in borderline (2.3 +/- 1.6). The low est Ki-67 labeling index (LI) was found in benign cystadenom as (5.7% +/- 3.4%) and papillary mucinous cystadenomas (7.9 +/- 5.8%). In b orderline tumors mean LJ was 12.2 +/- 10.9% whereas well-differentiated car cinomas had higher LI (16.8 +/- 10.2%). There were no statistically signifi cant difference between the evaluated tumors and techniques applied. In our opinion the AgNOR count and Ki-67 LI do not appear useful for assessing di fferences between borderline and well-differentiated mucinous ovarian tumor s at stage I of clinical advancement.