[Non-Hodgkin large B-cell lymphoma of the bile duct mimicking a Klatskin tumor: case report].

The obstruction of the bile duct secondary to non-Hodgkin lymphoma is extremely rare. That's why we present the case of a 63-year-old female patient who sought medical attention due to jaundice, dark urine, acholia, and weakness. Laboratory results showed a cholestatic pattern, and an ultrasound revealed dilation of the intra and extrahepatic bile ducts, for which a cholangio resonance was ordered. It showed an expansive formation with ill-defined borders compromising the common hepatic duct associated with its stenosis. The initial suspicion was a Klatskin tumor, for which a biopsy was performed, which reported infiltration of a double expressor large B-cell lymphoma as a primary neoplasm of the bile duct. The patient underwent chemotherapy treatment with R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) and went into remission. Due to continuous episodes of cholangitis, a Roux-en-Y hepatic jejunal anastomosis with biliary tract reconstruction was performed. Currently, she remains in remission, seven years after the diagnosis. This case highlights the rarity of large B-cell non-Hodgkin lymphoma in the bile duct and emphasizes the importance of biopsy for effective treatment, combining chemotherapy for the underlying disease and surgery for obstructive complications.