Abstract
Scanning electron microscopy of resin casts was carried out on the vascular system of hepatoma in Chinese hamster. Casts of capillaries in the hepatoma were thin and fragmentary and formed a fine randomly arranged network in contrast to those in the liver with radial arrangement and central veins in centrilobular regions. Capillaries in the cancer merged into superficial venules corresponding to central veins while those in the border region merged into sinusoids of adjacent liver tissue. The superficial venules connected to tributaries of hepatic veins to drain into the posterior vena cava. Neovascularization did not occur by sprouting and anastomosing to form hair-pin loops of capillaries but by division of pre-existing vessels into smaller vessels, thus increasing the number of capillaries. The hepatic artery feeding the cancer was seemingly intact. There was no indication of arterio-portal shunts in the hepatoma.
