Hepatoblastoma is a rare liver tumor that affects children under 3 years old. It starts as a golf ball-sized tumor in the right lobe of the liver. Genetic disorders like Beckwith-Wiedemann syndrome and familial adenomatous polyposis can cause hepatoblastoma. Symptoms include abdominal swelling, weight loss, and jaundice. Treatment depends on the stage - early stage tumors can be surgically removed while later stages involve chemotherapy and then surgery. Without treatment, stage 4 hepatoblastoma is fatal.