{
  "abstract": "Introduction Pancreatic tissue autolysis is a major challenge in cytopathology. Our previous work showed that endoscopic ultrasound guided- fine needle biopsy (EUS-FNB) specimens stored >24 hours in CytoLyt demonstrate increased autolysis (15% vs 6%, P<0.01). As diagnostic yield depends on the entire pathway from needle to microscope, we implemented an integrated optimization programme addressing preservative choice, specimen handling, laboratory workflow and reporting expertise. This study evaluates the impact of these interventions on diagnostic accuracy and indeterminate reporting.Methods Comparative analysis of 567 consecutive hepatopancreatobiliary cytology specimens (Jan 2021–Dec 2022) versus 631 specimens (Jan 2024–Oct 2025). Three EUS operators used identical technique with standard 22G FNAB needles. Rapid on-site evaluation was not used. Interventions included: preservative optimization (CytoLyt to PreservCyt), standardized specimen collection (stylet extrusion, <1 ml saline rinse, dual 5 ml air flush), same-day processing (>90% <24 hours vs previous end-of-list batching), multi-level cell block sectioning (10–20 levels), and reporting by a dedicated pancreaticobiliary cytopathologist. Specimens were classified using the National Minimum Cytology Dataset (N1–N5).Results Biliary brushings improved substantially. Baseline rates were N1 5.4%, N2 23.4%, N3 40.6%, N4 12.5% and N5 18.0%, compared with optimised rates of N1 0.6%, N2 37.5%, N3 2.0%, N4 2.6% and N5 57.2%. Inadequate specimens were nearly eliminated (5.4%→0.6%, P<0.001) and indeterminate diagnoses (N3/N4) fell from 53.1% to 4.6% (P<0.001).For EUS-FNA/FNB solid lesions, baseline rates were N1 6.2%, N2 40.3%, N3 6.2%, N4 10.0% and N5 37.4%. After optimisation, N2 decreased to 24.3%, N3/N4 to 3.4%, and N5 increased to 57.8% (all P<0.001). (The apparent rise in N1 rates was attributable to cystic lesions, where 79.4% underwent diagnostic biochemistry); N1 rates for solid lesions remained stable. Malignancy detection improved substantially (37.4%→57.8%, P<0.001).Cell blocks were consistently adequate for molecular testing (KRAS, GNAS). Mean turnaround time improved from 12.9 to 4.6 days, and outsourcing fell from 77.4% to 2.1%.Conclusions Coordinated optimization across the cytopathology pathway produced major gains over fragmented or isolated interventions. The synergistic effect of improved preservative, standardized collection, rapid processing and specialist reporting reduced indeterminate diagnoses from 38% to 3%, with significant implications for cancer pathway efficiency preventing diagnostic delays. Although individual component effects cannot be isolated, the magnitude of improvement supports an integrated, reproducible model for centres seeking to optimise pancreaticobiliary cytology services without reliance on ROSE.",
  "authors": [
    {
      "affiliations": [
        "Department of Histopathology, East Lancashire Teaching Hospital, Blackburn, United Kingdom"
      ],
      "name": "Mohammed Faraz Ali Khan"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, East Lancashire Teaching Hospital, Blackburn, United Kingdom"
      ],
      "name": "Durgesh Rana"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, East Lancashire Teaching Hospital, Blackburn, United Kingdom"
      ],
      "name": "Imran Mehrban"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, East Lancashire Teaching Hospital, Blackburn, United Kingdom"
      ],
      "name": "Nadira Narine"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, East Lancashire Teaching Hospital, Blackburn, United Kingdom"
      ],
      "name": "Rashmi Ratnakaran"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, East Lancashire Teaching Hospital, Blackburn, United Kingdom"
      ],
      "name": "Charlotte Ebenezer"
    },
    {
      "affiliations": [
        "Department of Histopathology, East Lancashire Teaching Hospital, Blackburn, United Kingdom"
      ],
      "name": "Hassan Hatab"
    },
    {
      "affiliations": [
        "Department of Histopathology, East Lancashire Teaching Hospital, Blackburn, United Kingdom"
      ],
      "name": "Mohamed Shibeika"
    },
    {
      "affiliations": [
        "Department of Histopathology, East Lancashire Teaching Hospital, Blackburn, United Kingdom"
      ],
      "name": "Venkat Mahesh"
    }
  ],
  "title": "P336 Beyond indeterminate: achieving definitive pancreaticobiliary cytology diagnoses through whole-pathway optimization",
  "uid": "1f1c6881-1eee-5648-8a76-a182d5a45782"
}