Evaluation of Ki-67 Immunostaining in the Differential Diagnosis of Low Grade Squamous Intraepithelial Lesion and Normal Cervix

Objective: Ki-67 immunostaining is used as an adjunct in the differential diagnosis of squamous intraepithelial lesions (SILs) of the cervix. The aim of this study was to determine an index for positive Ki-67 staining and the Ki 67-positive cell clusters for distinguishing normal cervix and low-grade squamous intraepithelial lesions (low-grade SILs). Materials and Methods: Thirty-four cervical specimens, in which 17 were previously diagnosed as normal and 17 low-grade SILs were included in the study. Ki-67 immunohistochemical staining was performed using avidin biotin complex. Results: After reevaluating the cases by means of histo-pathological and Ki-67 immunostaining features, 21 of 34 cases were diagnosed as normal cervix and 13 were diagnosed as low-grade SILs. Ki-67 index was higher in low-grade SILs (p<0.05). Although Ki-67 positive cell clusters was not observed in normal cervix, 77% of 13 low-grade SILs had positive cell clusters (p<0.05). Discussion: Ki-67 immunostaining may be considered as an easy and reproducible technique in differential diagnosis of normal cervix and low-grade SIL.