An analysis of surgical treatment for IPNBs based on the carcinoma case in myasthenia gravis and IgG4 related sclerosing cholangitis with autoimmune pancreatitis patient

Abstract

Intraductal papillary neoplasm of the bile duct (IPNB) of the liver is a rare tumor whose long term clinical behavior is still unknown. IPNBs were known as precancerous lesion like IPMNs of the pancreas pathologically, but clinically, an optimal timing of surgical treatment has not been discussed different from IPMNs. In this study, we experienced a unique case of IPNB involving myasthenia gravis (MG) and IgG-4 related sclerosing cholangitis (IgG4-SC) with autoimmune pancreatitis in a 65-year-old male patient. An initial 3cm simple cystic lesion in S3 liver had become aberrant with peripheral biliary dilatation in 2 years. The impact of IgG4-SC gave some difficulty in deciding how to treat it. Finally, a left hepatectomy was completed with R0 resection. The resected specimen revealed a gastric type IPNB with carcinoma in situ. Steroids treatment was inevitable for IgG4-SC and MG. Then IgG4-SC became exacerbated in a year and high dose steroid administration was critical. Intra- or extrahepatic bile duct cancer has not been detected in 2 years after surgery. IPNBs are biliary disorders with similar pathological features to IPMNs. About 60% of IPNBs have developed in the left lobe of liver similar to our case, and the 5-year survival rate has been reported as 83.9%, 75.4% and 46.8% in gastric type, intestinal type and pancreaticobiliary type, respectively. However, the clinical behavior remains unclear. This case suggested the critical gist of IPNB's biological behavior and optimal timing of surgery. Further analysis will be needed to clarify clinical essentials of IPNBs.