小児の胆管拡張型膵・胆管合流異常切除例に発癌関連遺伝子HDACが高発現していた1例

Pancreaticobiliary maljunction（PBM）is the congenital malformation that the junction of the pancreatic and bile ducts is located outside of the duodenal wall anatomically, so sphincter function preventing to mix the bile and pancreatic juice does not act. In PBM, the mutual reflux of bile and pancreatic juice induces various diseases and becomes the cause of biliary tract cancer generation. PBM is divided into PBM with the biliary dilatation and PBM without the biliary dilatation. From the perspective of carcinogenesis, surgery to separate the pancreatic juice and bile by excision of extrahepatic biliary tract and hepaticojejunostomy is commonly performed in the former, the treatment of the latter is controversial, for instance ; the only cholecystectomy should be performed and excision of extrahepatic biliary tract is unnecessary or excision of extrahepatic biliary tract and hepaticojejunostomy should be done. In addition, histone acetylation and histone deacetylation is one of the important regulatory mechanism of gene transcription, the error of the balance between histone acetyltransferase（HAT）and histone deacetylase（HDAC）leads to carcinogenesis. In other words, HDAC has a carcinogenic potential. Overexpression of HDAC was found in the both resected gallbladder and bile duct mucosa of infant PBM patient with the biliary dilatation performed the excision of extrahepatic biliary tract and hepaticojejunostomy in our department. Appropriate treatment for PBM has not been established yet, but even infant case with PBM has carcinogenesis potential just like this case. In conclusion, further accumulation of cases including PBM without the biliary dilatation was thought to be essential though the excision of extrahepatic biliary tract and hepaticojejunostomy still seems to be required for infant PBM patient with the biliary dilatation.