Decoverslipping of Archival Cytology Aspirate Smears for Ancillary Studies: A Review of Methods and Institutional Experience With Freezer‐Based Techniques

INTRODUCTION: Archival cytology aspirate smears are increasingly used for ancillary testing, yet decoverslipping remains a practical bottleneck. This study reviews published decoverslipping methodologies and evaluates freezer-based strategies for aspirate smears. METHODS: Published decoverslipping techniques were reviewed and compared with respect to turnaround time, tissue preservation, safety and suitability for downstream applications. An institutional study at MD Anderson Cancer Center evaluated freezer-based decoverslipping (-20°C and -80°C) of archival aspirate smears (40 cases, 80 slides) across four freeze-duration groups (1-2 min, 3-5 min, 10 min and 15 min). RESULTS: Aspirate smears prepared with thick xylene-based mounting media and rigid glass coverslips were consistently resistant to cold-based removal, with complete removal achieved in only 26 of 80 slides (32.5%), corresponding to 22 of 76 evaluable aspirate slides (28.9%). The highest per-slide success rate was observed at 10 min (15/40; 37.5%). A directional advantage for -80°C over -20°C was apparent but insufficient to overcome the fundamental resistance of this preparation type. Marked intra-case variability indicated that slide-specific factors were the dominant determinants of outcome. CONCLUSION: Mounting-media thickness and coverslip composition are primary determinants of decoverslipping success and represent under-recognised preanalytical variables. These findings underscore the need to align coverslipping workflows with anticipated downstream ancillary testing requirements.