Cystic lesions of the liver are common. Most of these represent benign simple cysts that generally require no intervention. The diagnosis of simple hepatic cysts is straightforward in the face of typical radiographic findings; however, diagnostic uncertainty, based solely on radiographic criteria alone, is not an uncommon clinical dilemma. In this report, we present a case of a 47 old woman with a cystic liver lesion and acute epigastric pain. The patient had no previous history of oral contraceptive assumption or liver disease. A tender mass was palpable on the upper right quadrant of the abdomen. The abdominal ultrasound (US) showed a cystic lesion with a possible hemorrhagic component on right liver lobe. Abdominal computed tomography (CT) and magnetic resonance (MR) revealed a complex cystic lesion with possible intracystic hemorrhage. The patient was submitted to operation and resection; the final histologic diagnosis revealed a primary undifferentiated embryonal sarcoma of the liver. She relapsed 24 months after a new hepatic resection and chemo-embolization, she is alive at 29 months after first surgery.