Application Value of Two-Dimensional Ultrasound Combined with Contrast-Enhanced Ultrasound for the Diagnosis of Multiple Bile Duct Hamartomas: A Case Report

: Bile duct hamartomas (BDHs), also known as von Meyenburg complexes, are small neoplasms of the liver, of which the pathology is a benign bile duct malformation. We report a case of multiple BDHs of a 55-year-old male diagnosed using two-dimensional (2-D) ultrasound combined with contrast-enhanced ultrasound (CEUS) and further clinically diagnosed using magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP). The 2-D ultrasound showed diffusely distributed hyperechoic nodules and cystic masses in the liver, accompanied by small strong echoes with a comet tail sign. The CEUS showed that the hyperechoic nodules observed no abnormal enhancement in the arterial phase and equal enhancement with the surrounding liver tissue in the portal vein and delayed phase. We conclude that the appearance of BDHs on ultrasound has distinct characteristics and can be used as the preferred method for diagnosis. The CEUS can differentially diagnose the disease and improve diagnostic accuracy. Therefore, 2-D ultrasound, combined with CEUS, is a helpful method for diagnosing BDHs.