Article

GNAS codon 201 mutations are uncommon in intraductal papillary neoplasms of the bile duct

Departments of Pathology Oncology Surgery, Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA Department of Surgery, University of Bonn, Bonn, Germany Ludwig Center for Cancer Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA State Key Laboratory of Cancer Biology, Cell Engineering Research Center & Department of Cell Biology, The Fourth Military Medical University, Xi'an, China Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA Department of Pathology, Emory University School of Medicine, Atlanta, GA, USA Department of Oncology, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
HPB (Impact Factor: 2.05). 10/2012; 14(10):677-683. DOI: 10.1111/j.1477-2574.2012.00504.x
Source: PubMed

ABSTRACT Background:  Activating point mutations of GNAS at codon 201 have been detected in approximately two thirds of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. Intraductal papillary neoplasms of the bile ducts (IPNBs) morphologically resemble pancreatic IPMNs. This study sought to assess the mutational status of GNAS at codon 201 in IPNBs. Methods:  Thirty-four patients were included. DNA from microdissected IPNBs was subjected to a polymerase chain reaction and ligation method for the detection of GNAS mutations at codon 201 and of KRAS mutations at codon 12. Mutational status was compared with clinical and pathologic data. Results:  The IPNBs had a median diameter of 3.5 cm and were located intrahepatically (n= 6), extrahepatically (n= 13), both intra- and extrahepatically (n= 4) or in the gallbladder (intracystic papillary neoplasms, n= 11). Most exhibited pancreatobiliary differentiation (n= 20), high-grade dysplasia (n= 26) and an associated adenocarcinoma (n= 20). Analysis of GNAS codon 201 identified only one mutant sample in a multifocal intestinal subtype intrahepatic IPNB with high-grade dysplasia. Six lesions harboured a KRAS codon 12 mutation. Conclusions:  GNAS codon 201 mutations are uncommon in IPNBs, by contrast with pancreatic IPMNs. More comprehensive molecular profiling is needed to uncover the pathways involved in IPNB development.

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