Automated Pap Tests

Abstract

A decade ago, very few cytology laboratories were engaged in automated cytology. Since then, several automated preparation devices have been introduced including instruments for cell collection from liquid samples, monolayer slide preparation, and autostainers. Computers were interfaced with cytology microscope stages (e.g., AcCell Series 2000, Pathfinder System, Cytosafe System) to assist with screening, by ensuring that all fields on a slide were examined. Manual Pap test screening remained a challenge because this task was (and still is) repetitive, labor-intensive, suffers from a significant false negative rate, carries ergonomic risk, and can be affected by the screening environment. This difficulty is compounded by the shortage of skilled cytotechnologists, which ushered in the need for automated screening of Pap tests. Early semi-automated screening devices were plagued by lack of a standardized sample, the conventional Pap smear, conducive to rapid digital image acquisition and computer processing. This resulted in the advent of Liquid-Based Cytology (LBC) with production of a cellular “monolayer” on a glass slide. Today, advances in computing, innovative software and digital imaging technology have been leveraged to successfully automate Pap test screening.