Fusion of old and new: employing touch imprint slides for next generation sequencing in solid tumors

Abstract

BackgroundCytomorphological evaluation of tissue touch imprints during rapid on-site evaluation or intraoperative pathology consultation has crucial value. However, literature on their utility for molecular testing is limited. In this study, we emphasize a further benefit of touch imprint slides and scrutinize our institutional experience on their use in molecular testing, specifically next generation sequencing (NGS).Materials and MethodsNGS-based reports (2019-2023) of Koc University Hospital were retrospectively analyzed and circumstances in which sequencing was conducted on touch imprint slides were retrieved (n = 18). Type/location of the biopsy, diagnosis, results, and quality metrics were recorded.ResultsTouch imprints were addressed when they harbored more neoplastic cells compared with permanent biopsies, when suboptimal fixation mitigated deoxyribonucleic acid/ribonucleic acid (DNA/RNA) yield in resections or when the sample was obtained from bone and required decalcification. Diagnoses were diverse, namely non-small-cell lung cancer, gastric adenocarcinoma, glial tumor, Ewing sarcoma, and carcinoma of unknown primary. The percentage of tumor cells on slides stretched between 15% and 70%. Molecular findings ranged from KRAS mutations to TRIM1