ULTRASTRUCTURAL-STUDY OF THE VASCULAR-RESPONSE IN SMALL EARLY GASTRIC-CANCER

The microvasculature of the stroma of four cases of small early gastri c cancer (EGG) was investigated by conventional electron microscopy. S evere damage to small and large fenestrated capillaries was observed a round endothelium-adherent, partially degranulated neutrophils. The fi ndings suggest the existence of neutrophil-mediated injury of endothel ial cells during the development of inflammatory responses in small EG G. The severely injured microvessels exhibited increase in vasopermeab ility, microhaemorrhage, and platelet aggregates. Other microvascular changes included endothelial cell and pericyte activation as well as b asal lamina replications, indicative of repeated episodes of endotheli al injury, necrosis and regeneration. This new capillary growth within the old basal laminas shared morphological features with a peculiar a ngiogenic process described in man and animals.