O‐3
a Study to Determine Whether There Is Significant Cell Loss on the Discarded Thinprep Broom When Used for Cervical Cytology

Abstract

Introduction: The aims of this study were to find out whether cells could be lost on the discarded ThinPrep (TP) broom. A similar study with SurePath (SP), whose methodology recommends leaving the broom in the vial, showed that cells were lost if the broom was discarded and that the amount was operator dependent.1 Methods: Three experienced colposcopists (C1, C2 and C3) collected TP samples from 306 women. The broom was rinsed thoroughly in a vial (V1) and then rinsed and retained in a second vial (V2). Slides from each case were randomised as A or B to conceal whether they were from V1 or V2, double‐screened and a cytological diagnosis and cell count recorded for each one. Cells were counted in 10 high‐power fields (HPF) and the cellularity classified as follows: high (HC) > 20 per HPF, intermediate (IC) 10–20 per HPF and low (LC) <10 in order to quantitate the cells potentially discarded in V2. Results: The percentages with high‐grade and low‐grade abnormal cytology decreased with the degree of cellularity of the slide. Abnormal cytology was found in 96/133 (72.2%) of HC, 85/131 (64.9%) of IC and 15/42 (35.7%) of LC in V1 and in 5/8 (62.5%) of HC, 35/54 (64.8%) of IC and 86/244 (35.2%) of LC in V2. The cellularity of V2 was HC or IC in 62/306 (20.3%) and varied between the colposcopists: C1 39/109 (35.8%); C2 20/103 (19.4%); C3 3/94 (3.2%). C1 would have discarded the most cells but had the lowest percentage with LC in V1: 9/109 (8.3%) while the average was 42/306 (13/7%). Abnormal cytology in V2 was also found in V1 in 113/126 (89.1%). Discussion: Abnormal cells would have been discarded with the TP broom and the amount varied between the colposcopists. This finding could have an affect on adequacy of the sample used for routine diagnosis. Reference: 1. Bigras G, Rieder MA, Lambercy J‐M et al. Keeping collecting device in liquid medium is mandatory to ensure optimized liquid‐based cervical cytology sampling. J Lower Genital Tract Dis 2003;7:168–74.

Are significant numbers of abnormal cells lost on the discarded ThinPrep® broom when used for cervical cytology?

“…TP samples were only carried out at colposcopy for studies such as this until the laboratory converted to LBC in 2006. This study was presented to the British Society for Clinical Cytology (BSCC) in 2006 6 . Since then, we have used its results to define the level of cellularity required for an adequate TP sample, which was presented to the BSCC in the following year 7 .…”