Undifferentiated embryonal sarcoma of liver with macroaneurysms and arteriovenous shunt.

Undifferentiated embryonal sarcoma (UES) is an uncommon primary hepatic tumour of childhood. The mass usually shows paradoxical features of being cystic on CT and solid on ultrasound. These lesions are usually hypovascular. Very rarely they may present as hypervascular liver masses with macroaneurysms and arteriovenous (AV) shunt, with only less than six cases reported in literature. We report a case of an 11-year-old child who presented with progressive abdominal distention, and CT revealed a large exophytic hypervascular mass of liver with multiple macroaneurysms, pooling of contrast and a high-flow AV shunt. Histopathology, along with immunohistochemistry, revealed the mass to be UES. The child underwent neoadjuvant chemotherapy followed by successful surgery. The prognosis of this tumour depends on prompt diagnosis and early intervention. We present this case to highlight the atypical presentation of UES, which will encourage radiologists to keep this differential in relevant clinical settings.