Primary follicular lymphoma of the common bile duct mimicking cholangiocarcinoma.

Primary non-Hodgkin's lymphoma of the common bile duct is extremely rare. We present a case with history of inflammatory bowel disease and clinical manifestations of obstructive jaundice. Abdominal magnetic resonance imaging with magnetic resonance cholangiopancreatography (MRCP) was done and demonstrated tight stricture at the middle part of common bile duct, and radiological findings were supportive of extra-hepatic cholangiocarcinoma. Whipple's procedure was performed and the case was histopathologically proven to be non-Hodgkin's lymphoma of follicular subtype involving the common bile duct. Lymphoma of the hepatobiliary system is usually present as secondary manifestation of systemic malignant lymphoma. However, primary malignant lymphomas arising from the hepatobiliary tree are extremely rare. The radiological appearance of common bile duct lymphoma is very similar to cholangiocarcinoma, making preoperative diagnosis very difficult, as in our present case. We also compare the imaging findings of our case to those seen in reported cases of follicular lymphoma of the common bile duct.