ADULT MESENCHYMAL HAMARTOMA OF THE LIVER MIMICKING BILE-DUCT CYSTADENOMA

We report a rare case of mesenchymal hamartoma in the cirrhotic liver of a 52-year-old Japanese male. The tumor, 3.5 cm in diameter, contain ed a cystic lesion and was located in the lateral segment. Bile duct c ystadenoma was considered most likely preoperatively because of the pa tient's age and the normal levels of tumor markers. However, since mal ignancy of the lesion could not be ruled out by preoperative imaging d iagnosis, lateral segmentectomy was performed. Histological examinatio n led to a diagnosis of mesenchymal hamartoma, since the lesion consis ted of a multilocular abnormal bile duct accompanied by abundant myxom atous or loose collagen.