Morphological Classification of Intraductal Papillary Neoplasm of the Bile Duct with Survival Correlation

Background: Intraductal papillary neoplasm of the bile duct (IPNB) is a specific entity for which there has been no classification that correlates clinical presentation with patient survival. We, therefore, propose a new classification based on radio-pathological appearance correlated with clinical findings including outcome. Methods: We retrospectively reviewed the medical and pathological records of 103 IPNB patients who underwent curative-intent hepatic resection between January 2008 and December 2011. A morphological classification was then created based on the presence of (a) bile duct dilatation, (b) intraductal mass(es), (c) cystic lesion(s), and (d) macro-invasion of the liver. All clinical parameters and survival were analyzed. Results: The median survival of IPNB patients was 1,728 days (95%CI: 1,485 to 1,971 days). The proposed classification predicted survival very well (log-rank test; p < 0.01). For patients with the cystic variant and micro-papillary IPNB, there were no tumor-related deaths within 3 years of surgery and median survival was not reached during the follow-up. The respective median survival times for IPNBs with unilateral intrahepatic duct dilatation, bilateral intrahepatic duct dilatation, and macro-invasion were 1,888 days (95%CI 1,118- 2,657), 673 days (95%CI: 392- 953), and 578 days (95%CI: 285- 870). Conclusion: We propose a new classification for IPNBs which not only provides a view of patients in terms of their radio-pathologic status but also should help in guiding planning of surgical procedures.