A case of lymphoid polyposis of the bile duct accompanied with diffuse wall thickening of the extrahepatic bile duct

Abstract

The case was a 75-year old man. Intraductal ultrasound (IDUS) indicated diffuse, irregular wall thickening with the formation of several protruding lesions in the extrahepatic bile duct. There was a hypoechoic layer within the protuberance. Histology did not indicate malignant cells, but because irregular thickening of the walls of the extrahepatic bile duct was indicated, we performed a pancreaticoduodenectomy. Although the resected specimen was identified as having hyperplasia with intramucosal lymphoid follicles and there was no indication of malignancy, the diagnosis was lymphoid polyposis of the bile duct. EUS and IDUS images of the extrahepatic bile duct identified in this case are important findings to suggest the benign tumor of the biliary tract.