RESUMO
A 20-year-old woman was admitted with abdominal pain and a cystic liver tumor. A hemorrhagic cyst was suspected. Contrast-enhanced computed tomography(CT)and magnetic resonance imaging(MRI)revealed a space-occupying solid mass in the right lobule. Positron emission tomography(PET)-CT revealed 18F-fluorodeoxyglucose uptake in the tumor. We performed a right hepatic lobectomy. Histopathological evaluation of the resected tumor revealed an undifferentiated embryonal sarcoma of the liver(UESL). The patient refused adjuvant chemotherapy but showed no recurrence 30 months postoperatively. UESL is a rare malignant mesenchymal tumor that occurs in infants and children. It is extremely rare and is associated with poor prognosis in adults. In this report, we described a case of adult UESL.