The Role of Micronucleus Scoring in Cervical Papanicolaou Smears: A 1-Year Study

AIMS AND OBJECTIVES: To compare the micronucleus (MN) score in all the major diagnostic categories as per “The Bethesda System for Reporting Cervical Cytology” 2014 including negative for intraepithelial lesions and malignancy (NILM), inflammatory, abnormal squamous cells of undetermined significance (ASC-US), abnormal squamous cells cannot exclude high-grade squamous intraepithelial lesion (HSIL) (ASC-H), low-grade squamous intraepithelial lesion (LSIL), HSIL, and invasive carcinoma (IC) and to assess the role of MN scoring as a biomarker for predicting risk of carcinoma. MATERIALS AND METHODS: A total of 1000 conventional cervical smears stained with Papanicolaou (Pap) stain, comprising unsatisfactory for evaluation (86), NILM (140), inflammatory (696), ASC-US (23), ASC-H (16), LSIL (18), HSIL (15), and IC (6) were studied independently by two pathologists, and the number of MN cells per 1000 epithelial cells in high-power (×400) and oil immersion (×1000) was counted and expressed as MN score per 1000 cells. RESULTS: The mean MN score ± standard deviation was found to be 0.99 ± 0.744 in NILM cases, 0.67 ± 0.782 in inflammatory cases, 1.57 ± 0.507 in ASC-US cases, 1.63 ± 0.50 in ASC-H cases, 1.56 ± 0.511 in LSIL cases, 2.47 ± 0.516 in HSIL cases, and 3.0 ± 0.00 in IC cases. A step-wise increase was observed in MN score from inflammatory to IC categories. CONCLUSIONS: MN score is a reliable and easy test that can be used in conjunction with routine cervical PAP to assess the risk of malignant transformation in the uterine cervix as a biomarker for predicting the risk of carcinoma.