Membranous obstruction of the inferior vena cava and invasion of the inferior vena cava by tumour in hepatocellular carcinoma.

A 28 yr old Zulu presented with a painful swelling in the right hypochondrium and severe swelling of the legs of short duration. The serum alpha-fetoprotein concentration was over 2 X 10(5) ng/ml and imaging showed a large hepatic mass-lesion. Radionuclide venography revealed no flow through the inferior vena cava but flow through a large collateral vessel. Contrast venography showed the upper portion of the inferior vena cava to be occluded: large collateral vessels arose from the lower vena cava and the iliac veins. The histological features were those of longstanding hepatic venous outflow obstruction with irregular centrizonal and portal fibrosis: severe acute centrizonal congestion was not seen. This combination of findings indicates the presence of both membranous obstruction of the inferior vena cava, a rare developmental abnormality which predisposes to hepatocellular carcinoma formation, and invasion by the tumour of the inferior vena cava via the hepatic veins, an uncommon complication of hepatocellular carcinoma.