FINE VASCULATURE OF HEPATOMA IN CHINESE-HAMSTERS (CRICETULUS-GRICEUS)- SCANNING ELECTRON-MICROSCOPY OF RESIN CASTS OF BLOOD-VESSELS

Scanning electron microscopy of resin casts was carried out on the vas cular system of hepatoma in Chinese hamster. Casts of capillaries in t he hepatoma were thin and fragmentary and formed a fine randomly arran ged 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 t hose in the border region merged into sinusoids of adjacent liver tiss ue. The superficial venules connected to tributaries of hepatic veins to drain into the posterior vena cava. Neovascularization did not occu r by sprouting and anastomosing to form hair-pin loops of capillaries but by division of pre-existing vessels into smaller vessels, thus inc reasing the number of capillaries. The hepatic artery feeding the canc er was seemingly intact. There was no indication of arterio-portal shu nts in the hepatoma.