Magnetic Resonance Imaging Findings of an Intrahepatic Bile Duct Adenoma: A Case Report

Bile duct adenoma (BDA) is a benign tumor that arises from the epithelium of the intrahepatic bile ducts. Herein, we present a case and discuss the characteristic magnetic resonance imaging (MRI) features of intrahepatic BDA by radiologic-pathologic correlation. A 41-year-old male visited our hospital. He was incidentally shown to have a liver-occupying lesion during a routine medical examination. MRI revealed a 16 mm × 17 mm × 18 mm circular hepatic mass occupying segment 2 of the liver. It showed low signal intensity on T1-weighted images (T1WI) and high signal intensity on T2-weighted images (T2WI). Diffusion-weighted imaging (DWI) MRI showed a ring of high intensity. Gadolinium ethoxybenzyl diethylenetriaminepentaacetic (Gd-DTPA) dynamic enhanced scanning showed a prolonged “ring enhancement” pattern. It showed a ring of high intensity in the hepatobiliary specific period and low signal peripheral and central of the tumor. The pathology result of the surgical resection showed a diagnosis of intrahepatic BDA. Postoperatively, the patient is currently under outpatient observation for seven months with no apparent recurrence. Intrahepatic BDA can be characterized as a small circular lesion located in the liver. MRI and pathologic features are well characterized in this tumor. MRI enhancement plays an important role in the diagnosis and evaluation of BDA.