Cholangiographic spectrum of intraductal papillary mucinous neoplasm of the bile ducts

OBJECTIVE: To propose a cholangiographic classification for intraductal growth type intrahepatic cholangiocarcinoma (IG-ICC) and its precursor, collectively termed intraductal papillary mucinous neoplasm of the bile ducts (IPMN-B). SUMMARY BACKGROUND DATA: For the extensive clinicopathologic variations of IPMN-B, a detailed characterization of cholangiography for IPMN-B is beneficial for determining the optimal therapeutic strategy. METHODS: A total of 124 patients with cholangiography-available and pathologically proven IPMN-B were retrospectively studied. Numbers of IPMN-B type 1, type 2, type 3, and type 4 were 33, 17, 15, and 59, respectively. A cholangiographic classification was proposed based on the presence of hepatolithiasis, mucobilia, neoplasia localization, and concomitant malignancies. The demographics, histologic grading, management, and survival were also analyzed. RESULTS: All 33 IPMN-B type 1 and 12 of 17 IPMN-B type 2 displayed cholangiographic pattern IA demonstrating hepatolithiasis-related biliary stricture. The remaining 5 IPMN-B type 2 displayed cholangiographic pattern IB or IC, which demonstrated mucobilia without discernible neoplasia. Seven of 15 IPMN-B type 3 and 52 of the 59 IPMN-B type 4 displayed cholangiographic pattern IIA or IIB, which demonstrated overt intraductal neoplasia. Seven IPMN-B type 3 or 4 displayed cholangiographic pattern IIIA or IIIB, which demonstrated IPMN-B and concomitant malignancies. For those presenting with cholangiographic pattern IA, IC, IIA, IIB, and IIIA, straightforward hepatectomies for the diseased lobes were performed. For those with pattern IB, surgical resections were performed only when there was emergence of mucin-producing neoplasia. For those with IIIB, the concomitant malignancies were considered inoperable. No disease-related death occurred in IPMN-B type 1and 2. The mean survival rates of IPMN-B type 3 and type 4 were 55.5 ± 17.1 months and 36.9 ± 6.3 months, respectively. CONCLUSION: The presented cholangiographic classification facilitates the management for IPMN-B. Significant survival discrepancy at the various stages warrants a more aggressive surgical strategy.