SRS305 - Frozen section in gastrointestinal and hepatobiliary pathology: insights from a 17-year tertiary-centre experience

Abstract Background Frozen section (FS) is an important intraoperative diagnostic tool in gastrointestinal (GI) and hepatopancreaticobiliary (HPB) pathology. It enables real-time surgical decision-making but is susceptible to sampling, technical, and interpretive limitations. Methods A retrospective review was undertaken of all GI and HPB FS reports at Nottingham University Hospitals between January 2009 and June 2026. FS diagnoses were compared with final paraffin section results. Discrepancies were classified using the Royal College of Pathologists system, and turnaround time was assessed. Intraoperative management was analysed for cases with discrepancies. Results A total of 555 FS were performed: 473 HPB, 58 upper GI, and 24 lower GI. Twenty-three discrepancies (4.1%) were identified: nine liver, seven pancreas, four peritoneum/mesentery, one each rectum, lymph node, and bile duct margin. Fifteen were B2 errors (clearly incorrect diagnoses), two were B3 (areas of recognised inter-observer variation), six were deferred due to interpretive difficulty, and one was cancelled due to calcified tissue. In three patients (0.5%), FS directly influenced surgical management: one hepatic granuloma misinterpreted as carcinoma led to a delay in performing pancreaticoduodenectomy; one dysplastic bile duct margin was missed, later progressing to cholangiocarcinoma; and one lymph node FS was abandoned due to calcification (diagnosed to be metastatic on paraffin section). Among cases with complete data, the median turnaround time was 32 min (mean 37 min). Conclusions This series confirms high FS accuracy in GI and HPB pathology but highlights some pitfalls. Improved sampling, documentation, and workflow processes could optimise intraoperative consultation.