Clinicopathological features of intraductal papillary neoplasms of the bile duct: a comparison with intraductal papillary mucinous neoplasm of the pancreas with reference to subtypes

Abstract

Intraductal papillary epithelial neoplasms of the pancreatobiliary system (intraductal papillary neoplasm of the bile duct (IPNB) and intraductal papillary mucinous neoplasm (IPMN)) seem to share many clinicopathological features; however, IPNB has not been fully characterized. In order to understand the clinicopathological/immunohistochemical features of IPNB better, we compared 52 cases of IPNB with 42 cases of IPMNs with mural nodules. The IPNB cases were divided into two groups according to their histological similarity and according to five key histological findings. All IPNB and IPMN cases mainly affected middle-aged to elderly people, predominantly men. Mucin hypersecretion was less frequent in IPNB compared to IPMN. Group 2 IPNB more frequently had a higher histopathological grade and more extensive stromal invasion than IPMN. Group 1 IPNB and IPMN were further classified into four subtypes (gastric, intestinal, pancreatobiliary, and oncocytic). Although each subtype of IPNB and IPMN showed similar histology, the immunohistochemical results were different. The gastric type of IPNB was less frequently positive for CDX2, and intestinal IPNB was more frequently positive for MUC1 and less frequently positive for MUC2, MUC5AC, and CDX2 compared to each subtype of IPMN, respectively. In conclusion, IPNB and IPMN have some clinicopathological features in common, but mucin hypersecretion was less frequent both in IPNBs than in IPMN. Group 2 IPNB differed from IPMN in several parameters of tumor aggressiveness. Additional clinicopathological and molecular studies should be performed with respect to the subtypes of IPNB and IPMN.

Subtyping of intraductal papillary mucinous neoplasms – pitfalls of MUC1 immunohistochemistry

“…However, according to the current WHO Classification, and based on MUC IHC, the gastric microbiopsy specimens from our study would be misclassified as PB, even though all lesions showed low‐grade dysplasia. Recent articles and reviews quote the WHO classification or use identical anti‐tumor MUC1 antibodies with no reflection on this . Analyzing the five studies quoted in the WHO classification, three use an antibody with specificity against MUC1 core (DF3 or Ma552) , while the rest use an anti‐sialylated MUC1 antibody .…”

Intraductal papillary mucinous neoplasm of the intrahepatic bile ducts: a case report and literature review

“…They can both secrete mucus and cause corresponding blockages in the ducts. Most importantly, they are precancerous lesions [3]. In recent years, IPMN-P has been gradually recognized, but the understanding of IPMN-B is just the beginning.…”

“…The disease can occur in both intrahepatic and extrahepatic bile ducts, which are connected with bile ducts. About 1/3 of IPNB can secrete mucus, which is called intraductal papillary mucinous tumor of the bile ducts (IPMN-B) [2,3]. At present, the description of IPMN-B is rarely reported.…”

Clinicopathological Aspects and Diagnostic Problems in Patients with Intraductal Papillary Neoplasm of the Bile Duct

“…However, consistency of histological definition has not been observed, and the controversy of diagnosis is still referred to by clinical physicians and pathologists (11,21,23) Therefore, the clinical aspect of preoperative histological diagnosis and surgical indication has not yet been fully clarified. Our previous reports identified the various tumor morphologies of IPNB, good prognosis, and difficulty in comparison with similar biliary tumors (19,(24)(25)(26).…”

“…Two of the patients with IPNB did not show any solid mass lesion detected by conventional imaging examination. The follow-up strategy was clearly defined in IPMN of the pancreas, which is considered the counterpart disease of IPNB (10,20,23). If the clinical or imaging characteristics indicating low-grade malignancy in some patients with IPNB were clarified, a similar strategy to IPMN would be used.…”