[Liver mesenchymal hamartoma in adulthood. Report of a new case]

A case of hepatic mesenchymal hamartoma, found after sudden onset clinical and biological cholestasis, is reported in a 18-year-old man. Abdominal ultrasound examination and computed tomography showed a intrahepatic cystic tumor. The diagnosis of hepatic mesenchymal hamartoma was made by the pathological examination of the resected specimen. This rare tumor is found in most cases in children less than 2 years old. Thirteen cases in adulthood were already reported, five of them in Japanese patients. Our case is peculiar because no hepatic tumor was shown by ultrasound examination, 2 years before, the large size of cysts and presence of smooth muscle fibers in the wall.