DIAGNOSTIC VALUE OF AgNOR STAINING AND KI-67 (MIB1) EXPRESSION IN UTERINE SMOOTH MUSCLE TUMORS.

Uterine smooth muscle tumors are the most common human neoplasm. They are divided clinically as benign and malignant but there is another group of lesions which is difficult to place in these two categories, so-called STUMP and differentiation of these tumors on the basis of H&E staining is difficult. The goal of this study is to find distinguishing objective biomarker and a survey of proliferation markers comparing these three groups of tumors.

Materials &Methods: Twenty one cases in each group of the above mentioned tumors were selected randomly from pathobiology laboratories and studied by using IHC staining for Ki_67 expression and AgNOR method.

Results: Ki_67 was expressed in 63.15% of leiomyosarcomas, 4.76% of STUMPs and 0% of leiomyoma group. Ki_67 expression between leiomyosarcoma and STUMP, and also between leiomyosarcom and leiomyoma were significant (P<0.0001). Mean AgNOR dots were 2.55 ± 0.03, 4.04 ± 0.66 and 8.12 ± 0.13 in leiomyoma, STUMP and leiomyosarcoma, respectively. Significant differences between three groups were observed (P<0.0001).

Conclusion: AgNOR and Ki_67 (MIB1) proliferation markers expression between leiomyosarcoma and STUMP showed significant differences. Due to difficulty in differention of leiomyosarcoma from STUMP, finding objective biomarker is necessary. For this purpose, the present study recommends Ki_67 and AgNOR staining for this purpose and seems to be a reliable, simple, and rapid method.