Table of Contents
Definition / general | Clinical features | Case reports | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Molecular / cytogenetics descriptionCite this page: Gulwani H. Intraductal papillary neoplasm of biliary tract. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/gallbladderIPMN.html. Accessed April 24th, 2024.
Definition / general
- Uncommon
- Solitary or may spread along biliary tree to cystic duct or duodenal papilla
- May resemble intrapapillary mucinous neoplasms of pancreas as both arise within a dilated duct system and demonstrate predominantly intraductal growth
- Risk factor for cholangiocarcinoma, biliary obstruction, recurring ascending cholangitis
- Are often carcinomas (HPB (Oxford) 2009;11:684)
- p21, p53, cyclin D1, DPC4 are involved in neoplastic progression (Hum Pathol 2008;39:1153)
Clinical features
- Preinavsive neoplasms at least 1 cm (Am J Surg Pathol 2012;36:1279)
- Analogous to pancreatic (IPMN) and biliary counterparts
- Show variable cellular lineages with a spectrum of dysplasia, mixture of papillary or tubular growth patterns
- Relatively indolent behavior - better prognosis than pancreatobiliary type gallbladder carcinoma
Case reports
- 67 year old woman with polypoid mass (Pathol Int 2010;60:516)
Gross description
- Either polypoid, cast-like growth, superficial spreading or cystic type but does not correlate with prognosis (Abdom Imaging 2011;36:438)
Gross images
Microscopic (histologic) description
- Papillary fronds with fine vascular cores
- Epithelial cells are either biliary type or have gastric or intestinal differentiation with goblet cells and Paneth cells
- Production of extracellular intraductal mucin less common than papillary IPMN
- Variants have oncocytic changes or cysts (Mod Pathol 2006;19:1243)
- Borderline tumor: mild to moderate nuclear atypia and nuclear pseudostratification limited to basal 2/3 of the epithelium
- Carcinoma: severe cytological atypia, loss of nuclear polarity or architectural cribriforming / papillary fusion is present
Microscopic (histologic) images
Positive stains
- MUC5AC, MUC6, claudin18 and HepPar1
- Variable CK20 (Hum Pathol 2002;33:503)
- Tumors with oncocytic changes have gastric phenotype (Hum Pathol 2009;40:1543), express Wnt pathway proteins beta catenin and E-cadherin (Pathology 2007;39:413)
Negative stains
Molecular / cytogenetics description
- KRAS activating mutations (29%), 18q- (31%) but no loss of DPC4
- Often has microsatellite instability (Mod Pathol 2002;15:1309)