A case of a patient with embryonal sarcoma presenting with abdominal pain

Undifferentiated embryonal sarcoma of the liver is a rare and aggressive pediatric neoplasm. Due to its features in the imaging studies, there is a high rate of misdiagnoses. We present a 16-year-old female referred to our hospital with abdominal pain. At the initial work-up, we suspected a hydatid cyst as one of differential diagnoses due to the cystic pattern of the mass on the computed tomography scan. The needle biopsy smear was sent for pathology analysis which was negative for scolex of Echinococcus granulosus . However, the pathology report indicated neoplastic features in the biopsy. She underwent surgery and total resection was performed. The mass was sent for further investigation which confirmed the diagnosis of embryonal sarcoma with osteosarcomatous components. Embryonal sarcoma should be suspected in large tumors at any age.