Interobserver variability amongst gastrointestinal pathologists in assessing prognostic parameters of malignant colorectal polyps: a cause for concern

Malignant colorectal polyps (MCRP) have become a major challenge in the field of coloproctology from diagnosis to full treatment. One important facet of the challenge is the histopathological staging of the lesion and identifying various prognostic parameters. The primary aim of this study was to find the interobserver variation amongst 4 experienced gastrointestinal pathologists when assessing important parameters and staging systems (Haggitt, Kikuchi and Ueno) in MCRPs. Four experienced gastrointestinal pathologists independently assessed 56 cases of MCRP, and each pathologist completed a pro forma for each case. The results were collated and statistically analysed. There was a significant variation in the assessments using the various published staging systems agreed upon on important prognostic parameters. None of the staging systems used is suitable for all polyp types or has good reproducibility. There is an urgent need to make pathologists' assessment of MCRPs easier and more reproducible.