Inflammatory Conditions of the Pancreatobiliary Tree.

Abstract

The Pancreatobiliary Pathology Society (PBPS) would like to thank Alain C. Borczuk, MD, and the Archives of Pathology & Laboratory Medicine for again highlighting our society by publishing 3 review articles based on the presentations at the PBPS companion society symposium, which was held at the 2021 United States and Canadian Academy of Pathology (USCAP) meeting. As always, PBPS's mission remains the education of surgical pathologists and cytopathologists about the importance of recent advances in this complex field, which will hopefully transform the way we practice pancreatobiliary pathology. The PBPS fosters excellence and international collaboration in education, research, and the global practice of pancreatobiliary pathology. PBPS became an official society in 2016 and a USCAP companion society in 2018. However, the sharing of knowledge, enthusiasm, and ideas in pancreatobiliary pathology actually began more than 20 years ago as an annual “Pancreas Club” luncheon, held during the annual USCAP meeting, which grew over the years and eventually became the PBPS. The first advisory council members of the Pancreas Club were Volkan Adsay, MD; Ralph Hruban, MD; David Klimstra, MD; Günter Klöppel, MD; and Giuseppe Zamboni, MD. Thanks to their continued dedication to pancreatobiliary pathology and contagious enthusiasm, many other pathologists interested in the field were attracted to join and motivated its transformation into the official 501c3 society that it is today (PBPath.org).Because of the COVID-19 pandemic, the 2021 annual USCAP meeting (and by extension the PBPS companion society meeting) was held virtually. The theme of the 2021 PBPS Companion Society Symposium was “Inflammatory Conditions of the Pancreatobiliary Tree.” It featured 1.5 hours of on-demand educational content provided by 4 invited speakers, as well as a live 30-minute question-and-answer session with the speakers and moderators, Michelle Reid, MD, MS, and Rondell Graham, MBBS. The theme of the 2021 meeting was updates on acute and chronic inflammatory conditions of the pancreatobiliary tree, and it featured 4 outstanding presentations by experts in the field (Barbara Centeno, MD, Vikram Deshpande, MD, Dr Klöppel, and Dr Zamboni) entitled (1) “Cytopathology of Inflammatory Lesions of the Pancreatobiliary Tree” (Centeno), (2) “IgG4-Related (Autoimmune) Pancreatitis” (Deshpande), (3) “Acute and Alcoholic Pancreatitis” (Klöppel), and (4) “Paraduodenal Pancreatitis” (Zamboni).All 4 presentations from the 2021 companion meeting have been converted into review articles and are featured in this issue of Archives of Pathology & Laboratory Medicine. In the first article, “Cytopathology of Inflammatory Lesions of the Pancreatobiliary Tree,” Dr Centeno reviews the cytopathology of inflammatory lesions of the pancreas and bile duct, including the different types of pancreatitis. The cytologic criteria useful for differentiating reactive ductal atypia from adenocarcinoma and other malignant mimics are also discussed, and the application of ancillary techniques for this differential diagnosis is emphasized. In addition, Dr Centeno reviews pertinent and best pathology practices in the application of ancillary immunohistochemical and molecular studies for the differential diagnosis of benign from malignant processes in the bile duct. The second article is entitled “Navigating the Challenges Associated With a Diagnosis of Autoimmune Pancreatitis and IgG4-Related Sclerosing Cholangitis” and is written by Dr Deshpande, along with his colleagues Osman Yilmaz, MD, and Karen Pinto, MBBS, DNB, FRCPath. In this article Drs Yilmaz, Pinto, and Deshpande examine the clinicopathologic features of type 1 and 2 autoimmune pancreatitis and immunoglobulin G4–related sclerosing cholangitis. They emphasize the use of a multimodal approach (clinical, radiographic, serologic, histopathologic, and immunohistochemical correlation) and highlight the distinctive overlapping qualities that can aid in diagnosing these entities and distinguishing them from other fibroinflammatory and/or neoplastic mimics. The authors also discuss diagnostic pitfalls and differential diagnoses and offer an approach to the interpretation of needle biopsies, including ampullary biopsies. The third article is entitled “Acute and Chronic Alcoholic Pancreatitis, Including Paraduodenal Pancreatitis.” It combines the talks of our third and fourth speakers, Dr Klöppel and Dr Zamboni. In this combined article, Drs Klöppel and Zamboni present the current state of pathology and pathogenesis of alcohol-associated pancreatitis, including paraduodenal pancreatitis. In the context of the most important epidemiologic, clinical, and radiologic features, the role of alcohol overconsumption and related macroscopic changes and histopathologic characteristics are addressed. Pathologic findings that distinguish mild from severe pancreatitis, as well as a histologic staging system for chronic pancreatitis, are emphasized. The morphologic features of paraduodenal pancreatitis as well as the anatomic peculiarities associated with it are also described.We are extremely proud of our society and the continued contributions of its members to the field of pancreatobiliary pathology. We hope that you will enjoy these review articles highlighting the experts' perspectives on inflammatory conditions of the pancreatobiliary tree.