Pedunculated Accessory Liver Lobe Containing the Gallbladder Presenting as Biliary Obstruction: A Case Report.

Accessory liver lobes (ALLs) are rare anatomical variations characterized by supernumerary lobes of normal hepatic parenchyma in continuity with the liver. They are typically asymptomatic and most often discovered incidentally during imaging or surgical procedures. We report a unique case of a three-month-old premature infant with a history of gastroschisis and bladder herniation, who developed clinical and biochemical signs of progressive cholestasis. Imaging studies raised suspicion for an ALL, which was confirmed intraoperatively as a pedunculated ALL in continuity with the gallbladder. The lobe was resected en bloc. ALLs are infrequently diagnosed and often present with nonspecific symptoms. While imaging may suggest the diagnosis, definitive identification is commonly made during surgery, as ALLs can mimic masses and raise concern for neoplastic disease. To our knowledge, this is the first documented case of a symptomatic ALL presenting with signs of biliary obstruction. This rare case highlights the importance of including ALL in the differential diagnosis of cholestasis, as delayed recognition may lead to secondary biliary cirrhosis, potentially necessitating liver transplantation.