Congenital absence of the portal vein.

A 4 1/2-year-old girl is described in whom the portal vein is absent and the venous return from the gastrointestinal tract, spleen, and pancreas is through the left renal vein into the inferior vena cava. She had a hepatoblastoma, which was treated surgically by right hepatic lobectomy. Regeneration occurred in the remaining left lobe within 3 months after surgery. This is the second such case documented in the literature.