Primary malt lymphoma of the common bile duct.

Primary mucosa-associated lymphoid tissue (MALT) lymphoma arising in the common bile duct (CBD) is extremely rare. In our case of MALT lymphoma, CT and MRI showed long, segmental, irregular wall thickening of the CBD and minimal dilatation of the upstream bile duct. A preoperative diagnosis of cholangiocarcinoma was made, but histologic evaluation confirmed MALT lymphoma of the CBD. We herein present a rare case of MALT lymphoma of the CBD with CT and MRI findings.