Intraductal papillary neoplasm of the bile duct (IPNB): CT and MRI appearance with radiology-pathology correlation

• Published in: Clinical imaging Vol. 66; pp. 10 - 17
• Main Authors: Aslam, Anum, Wasnik, Ashish P., Shi, Jiaqi, Sahai, Vaibhav, Mendiratta-Lala, Mishal
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2020; Elsevier Limited
• Subjects: Bile; Bile ducts; Blood clots; Cancer; Cholangiocarcinoma; Computed tomography; Correlation analysis; Dilation; Dysplasia; Ethnicity; Extra hepatic polypoidal mass; Frond-like; Gallbladder; Gallstones; Intestine; Intraductal papillary neoplasm of bile duct; Invasiveness; Lymphatic system; Magnetic resonance imaging; Medical imaging; Morphology; Pathology; Physical characteristics; Plaque-like stricture; Premalignant; Radiology; Stricture; Tumors; Upstream; Premalignant; Frond-like; Plaque-like stricture; Intraductal papillary neoplasm of bile duct; Cholangiocarcinoma; Extra hepatic polypoidal mass
• ISSN: 0899-7071; 1873-4499; 1873-4499
• DOI: 10.1016/j.clinimag.2020.04.036

Intraductal papillary neoplasm of the bile duct (IPNB) is a precursor to invasive carcinoma and is a distinct pathologic diagnosis. The purpose of this study was to evaluate imaging features of IPNB on cross-sectional imaging studies with histopathologic correlation. In this IRB approved, HIPAA compliant retrospective observational analysis of 23 pathology proven IPNB tumors 22 imaging studies were reviewed, 14 CT and 8 MRI scans. Features evaluated in consensus by two subspecialty-trained abdominal radiologists included: presence of specific lesion/mass within the bile duct, location within the biliary tree, size, morphology, enhancement characteristics, and bile duct caliber. Majority of the subjects (16/18, 90%) had definite intraluminal mass, of which 7 (39%) had a polypoid mass with upstream diffuse biliary ductal dilation and 5 (28%) had a plaque-like mass with focal stricture and upstream biliary ductal dilatation. 6/18 (33%) subjects had low grade dysplasia, most commonly intestinal subtype, 7/18 (39%) subjects presented with invasive component, commonly pancreaticobiliary subtype, and 5/18 (28%) presented with high grade dysplasia. IPNB has increased predilection for extrahepatic bile ducts, commonly presenting as either an intraluminal polypoidal mass with associated upstream biliary ductal dilation or a focal plaque like mass with associated ductal stricture at the site of the tumor. •IPNB, a precursor to invasive adenocarcinoma is analogous to pancreatic IPMN, albeit with a higher rate of malignant transformation compared to the latter•IPNB's most commonly present as an extrahepatic intraluminal polypoid mass with upstream biliary ductal dilatation, can present as a stricture with plaque like thickening and upstream biliary ductal dilatation and rarely as ductal dilatation without an associated mass•IPNB remains a challenging diagnosis as most cases overlap with imaging appearance of Cholangiocarcinoma, hence requiring a multidisciplinary approach for treatment and surveillance