Ki-67 immunostaining in Pap smears of cervix: assessment of proliferation in preinvasive and invasive squamous epithelial lesions.

Ki-67 is a novel proliferation marker. Its use has been extensively studied in biopsy sections of preinvasive and invasive squamous epithelial lesions of cervix. However, only limited work has been done on its application on Pap smears of cervix. We applied Ki-67 immunostaining on cytology smears of various grades of squamous epithelial lesions of cervix. Sixty cases were chosen for immunostaining by Peroxidase antiperoxidase method using DAB as a chromogen. High level of Ki-67 labelled proliferation was measured in squamous cell carcinomas of cervix. Statistically significant difference was observed between preinvasive and invasive squamous epithelial lesions of cervix. Ki-67 could prove as a useful adjunctive test to routine Pap smear in triage of patients harboring lesions of cervix.