An Audit, Review of Histopathologic Reporting and Reassessment of Venous Invasion Using Verhoeff Van Gieson Stain on Colorectal Cancer Resections at Kenyatta National Hospital

Abstract

Background: Colorectal carcinoma (CRC) was ranked as the third most common cancer worldwide and was responsible for the second highest number of cancer related deaths after lung cancer in 2020, according to World Health Organization. The gold standard in CRC diagnosis is histology confirmation of tissue biopsy. Therefore, a complete and accurate histopathology report of CRC resections is critical in managing CRC patients. This study aimed to audit histopathology reporting of CRC resections at KNH between January 2017 and December 2021, identify areas of inadequacies and make necessary recommendations. In addition, a histopathology review of the specimens was carried out to evaluate for inter-observer variations in reporting, and Verhoeff elastic stain (EVG) was used to investigate venous invasion in the reassessment cases. Objective: The primary aim of the study was to audit, review histopathology reporting and perform a histopathology reassessment of venous invasion using EVG stain on CRC resections at KNH. Study Design: A laboratory-based, retrospective descriptive study Study Area: KNH/UoN Histopathology laboratory Study Population: CRC resections that were reported between January 2017 and December 2021. Method: Laboratory request forms, histopathology reports and tissue blocks from CRC resections reported during the study period were retrieved. The histopathology reports were audited for completeness using CAP Protocol. Tissue sections were prepared and stained using H&E and EVG stain was used to reassess for venous invasion in specimens negative or equivocal for venous invasion on H&E. Results: Eighty seven cases of CRC resections were included in the study. In all the 7 cases reported without the use of proforma there was incompleteness of the reports compared to 63% cases when the proforma was used. The Kappa statistic ranged from 0.509 to 1.00 between initial reports and review reports which indicates weak to almost perfect agreement. Of the 60 cases reassessed with EVG for venous invasion only one was positive. Conclusion: There was incomplete adherence to CAP protocol of reporting CRC resections with only 34% of the cases complete. Concordance between initial and review reports ranged from weak to almost certain with Kappa statistic of 0.509 to 1.000 depending on various parameters. The use of elastic stain did not influence the detection of venous invasion in CRC resections.