Intraductal papillary neoplasm of the bile duct: review of updated clinicopathological and imaging characteristics

Background Intraductal papillary neoplasm of the bile duct (IPNB) is a relatively rare disease and is known as one of the premalignant lesions in the biliary tract. The concept of IPNB has changed through numerous studies and is still evolving. As a lesser studied clinical entity compared with its pancreatic counterpart, intraductal papillary mucinous neoplasm, IPNB has been described in many similar terms, including biliary papillomatosis, biliary intraductal papillary-mucinous neoplasm, and papillary cholangiocarcinoma. This is based on the diversity of histopathological spectrum of IPNB. Methods This review investigated previous studies including original articles, case studies, and expert opinions. Recently, two types of IPNB (types 1 and 2) have been proposed and validated based on the content first established in the WHO 2010 criteria. Results This review provides a comprehensive analysis of existing literature, summarizing the clinical, radiological, morphological, and pathological characteristics of IPNB. Conclusion Given the ongoing ambiguity and controversies surrounding IPNB, future research, including large population-based studies and molecular investigations, is essential to enhance understanding of this disease. The authors reviewed many previous studies, and summarized the clinical, radiological, morphological, and pathological characteristics of intraductal papillary neoplasm of the bile duct that have been established to date. They also identified some ambiguous areas that remain controversial. With this careful overview, a direction for the future study of this recently established disease entity is suggested. Lay Summary Intraductal papillary neoplasm of the bile duct (IPNB) is a rare condition that might cause bile duct cancer. It has not been studied as much as intraductal papillary mucinous neoplasm, a similar disease of the pancreas. The aim of this article was to look at past studies and sum up what we know about IPNB, such as how it shows up in tests and what it looks like. The authors studied earlier research to learn about IPNB, including its two main kinds, called type 1 and type 2, based on a 2010 list from the WHO. The authors found and listed the main features of IPNB by looking at past research. We still do not know a lot about IPNB, and sometimes experts disagree. More research with lots of people and detailed studies will help us understand this condition better.