Comparison between Thin Prep® Preparation (Liquid Based Cytology) and Conventional Pap Smears of Cervical Smear Cytology Lesions – A Study from Kanyakumari, Tamilnadu, India

Abstract

BACKGROUND The major cause of mortality among women is cancer of the uterine cervix. It is the second most common cancer worldwide. Pap smear is done as a method of cervical screening to detect precancerous and cancerous lesions of the cervix. Early detection of these lesions prevent the number of deaths from cervical cancer. Liquid based cervical cytology was developed to improve the diagnostic accuracy of pap smears. The main purpose of this study was to compare the profile of distribution of cervical smear cytology lesions obtained by thin prep preparation (liquid based cytology) and conventional pap method among women in the age group of 25 – 60 yrs. METHODS This is a cross sectional study done among 110 women from the outpatient department of Obstetrics and Gynaecology. Conventional and liquid based cytology smears were taken simultaneously from the same women and reported according to the 2001 Bethesda system. RESULTS Majority of the women included in this study fall in the age group of 41 - 50 years [65 (59.1 %)]. Women with a history of persistant vaginal infection were 13 (11.8 %). Out of the 110 pap smears taken by both conventional and liquid based methods, unsatisfactory smears were not detected in liquid based cytology and 6 (5.5 %) unsatisfactory smears were found in conventional pap method. In liquid based cytology, inflammatory smears were detected more (80 %), atrophic smears (2.7 %), smears with features of atypical squamous cells of undetermined significance (ASCUS) were 4.5 %, low-grade squamous intraepithelial lesion (LSIL) were 3.6 %, and smears with high-grade squamous intraepithelial lesion (HSIL) were 0.9 %. Epithelial cell abnormalities were found to be high in liquid based cytology. CONCLUSIONS Abnormal epithelial lesions were detected more in liquid based cytology (thin prep method). The number of unsatisfactory smears were found to be decreased when compared to conventional pap method. KEY WORDS Bethesda Cervical Cytology, Cervical intraepithelial lesion, Conventional Pap Smear, Liquid Based Cytology Smear