Mesenchymal hamartoma and undifferentiated embryonal sarcoma: diagnostic keys that radiologists need to know

Hepatic tumors are uncommon in pediatric patients. Among the most common of these uncommon tumors are mesenchymal hamartoma and undifferentiated embryonal sarcoma, which have different origins but similar appearance on imaging studies. This paper reviews the characteristic findings and differential diagnosis of these entities. Ultrasonography is the first-line imaging test to study these tumors. Magnetic resonance imaging and computed tomography are useful for further characterizing the tumors and planning surgery. Radiologists need to be familiar with the imaging findings of the different disease entities and to evaluate them together with the patient's age, personal history, and bloodwork.