A case of solitary bile duct hamartoma with advanced gastric carcinoma: findings in contrast-enhanced ultrasonography.

Bile duct hamartomas (BDH), which are also known as von Meyenburg complexes, are benign neoplasms that involve cystic dilatation of the bile duct surrounded by fibrous stroma. However, multiple lesions develop in most cases of BDH, whereas a solitary lesion, as seen in our case, is relatively rare. We report here the co-existence of gastric carcinoma and BDH mimicking metastasis in a 30-year-old woman. A lesion measuring 13 × 9 mm with the appearance of a hyperechoic nodule with no pulsatile blood flow signals was observed on US and Doppler US in S4 of the liver. On contrast-enhanced ultrasonography (CEUS), the septum-like structure in the tumor was weakly enhanced at 17 s after administration of Sonazoid. There has been no description of solitary BDH findings on CEUS in the literature. We present the US findings of BDH, including those yielded by CEUS using Sonazoid, along with the microscopic pathological correlation.