Banff 2022 pancreas pathology update: how to make the right diagnosis and decrease inconclusive pathology results

The Banff 2022 pancreas transplant pathology update is the most comprehensive to date. It has improved the criteria for T-cell and antibody mediated rejection, recognized other clinicopathological differential diagnoses, and addressed the critically important islet failures. Nevertheless, multidisciplinary discussions during and after the meeting showed a need to enhance the real and perceived value of pancreas transplant biopsies. In particular, the occurrence of clinicopathological discrepancies and/or inconclusive biopsy findings, result in considerable uncertainty in clinical and pathology decision making.

The current review expands on the 2022 report by presenting the most common situations leading to an inconclusive diagnosis (Banff "indeterminate" category), a major issue of discussion. The entities discussed herein are: nonspecific infiltrates versus active rejection; residual inflammation after treatment of active rejection; ischemic pancreatitis and peripancreatic reactions in the early posttransplant period; biopsy findings associated with exocrine drainage impairment, and other unusual or nonspecific findings. An algorithm for the evaluation of pancreas allograft biopsies is also presented, that should facilitate the interpretation of morphological findings.

Systematic integration of essential clinical information with the pathology findings can improve the diagnostic yield of pancreas allograft biopsies and reduce the cases with and "indeterminate" diagnoses.