Primary mesenchymal liver tumors of childhood.

Primary mesenchymal tumors of the liver represent a significant proportion of liver tumors among neonates, infants and young children. They may be discovered incidentally or present with an alarmingly large, rapidly growing abdominal mass. One third of pediatric liver tumors are benign with hemangioma and mesenchymal hamartoma being the commonest in that order. Infantile hemangioendothelioma and mesenchymal hamartoma represent the commonest liver tumors among neonates and infants. Mesenchymal hamartoma may even present in utero. A biopsy is often required for definitive diagnosis due to considerable overlap in clinical presentation and radiological findings amongst these tumors, as well as with hepatoblastoma.