Intraductal papillary mucinous neoplasm of the biliary tract: a real disease?

Abstract

Background: Despite increasing numbers of reports, biliary tract intraductal papillary mucinous neoplasm (BT-IPMN) is not yet recognized as a unique neoplasm. The aim of the present study was to define the presence of BT-IPMN in a large series of resected biliary neoplasms.

Methods: From May 1994 to December 2006, BT-IPMN cases were identified by reviewing pathology specimens of all resected cholangiocarcinomas and other biliary neoplasms when cystic, papillary or mucinous features were cited in pathology reports.

Results: BT-IPMN was identified in 23 out of 253 (9%) specimens using the strict histopathological criteria of IPMN. The most common presenting symptom was abdominal discomfort which was present in 15 patients (65%). Only one of the original operative pathology reports used the term IPMN; 16 (70%) used the terms cystic, mucinous and/or papillary. BT-IPMN was isolated to non-hilar extra-hepatic ducts in 12 (52%), intra-hepatic ducts in 6 (26%) and hilar extra-hepatic ducts in 5 patients (22%). Carcinoma was found in association with BT-IPMN in 19 patients (83%); 5-year survival was 38% after resection.

Conclusion: BT-IPMN occurs throughout the intra- and extra-hepatic biliary system and can be identified readily as a unique neoplasm. Broader acceptance of BT-IPMN as a unique neoplasm may lead to a better understanding of the pathogenesis of biliary malignancies.

Figure 1

Computed tomography depicting an intra-luminal polypoid lesion originating from the biliary tract in extra-hepatic (a) and hilar (b) locations

Figure 2

Photograph A shows a distal common bile duct intraductal papillary mucinous neoplasm (IPMN) with characteristic gross polypoid features. Photographs B–E show haematoxylin and eosin stains of different biliary tract (BT)-IPMNs with papillary cytoarchitecture within the benign portion (b), intestinal epithelium (c), pancreatobiliary epithelium (d) and oncocytic epithelium (e)

Figure 3

Kaplan–Meier curve depicting the survival for 19 patients who had carcinoma in association with BT-IPMN. Survival was 77% at 1 year (n= 13; 95% CI 60–100%), 46% at 3 years (n= 7; 95% CI 27–78%) and 38% at 5 years (n= 4; 95% CI 20–72%)