The Banff classification revisited.

From small beginnings in 1991, the Banff working classification of renal allograft pathology has grown to be a major force for setting standards in renal transplant pathology, and is widely used in international clinical trials of new antirejection agents. The meeting, classification, and consensus process have unique history, and look poised to continue for another several decades as the embodiment of the process for setting global standards in pathology. The Banff meetings have expanded from renal allograft pathology to most other areas of solid organ transplantation, and increasingly incorporate international working groups, so that productive collaborative activity is ongoing, creating an important dynamic process enhancing clinical success in transplantation. On the other hand, despite the successes of the working classifications and ongoing collaborative efforts, there are limitations in this and other pathological classifications, related to potential for sampling error, issues of reproducibility when implemented globally, and lack of formal incorporation of morphometry and molecular and genomics approaches. Some of these problems cannot be overcome within the realm of traditional histopathology, and will only be solved when the classification is able to confidently embrace genomics and molecular medicine parameters for all common diagnoses. The smooth integration of these newer technologies with traditional histopathology is one of the great challenges for the future.