Preoperatively undetected solitary bile duct hamartoma (von Meyenburg complex) associated with esophageal carcinoma.

Bile duct hamartomas, also known as von Meyenburg complexes, are benign neoplasms consisting of cystic dilatation of the bile duct surrounded by fibrous stroma. We report a rare case in a 60-year-old man who presented with coexistent von Meyenburg complex and esophageal carcinoma. Preoperative computed tomography did not reveal any liver tumors. Intraoperatively, a small lesion was discovered in segment III of the liver; the lesion was suspected to be a solitary liver metastasis from the esophageal carcinoma. Partial resection of the liver was performed, and pathological findings revealed bile duct hamartoma (von Meyenburg complex). As von Meyenburg complexes are small cystic lesions located throughout the liver, and as they do not present characteristic imaging findings, their preoperative morphological diagnosis and differential diagnosis from liver metastasis is extremely difficult. In conclusion, von Meyenburg complex should be considered in the differential diagnosis of intrahepatic cystic neoplasms.