[The ultrastructural changes of infiltrating gastric carcinoma cells and their surrounding structures]

The ultrastructural changes of infiltrating gastric carcinoma cells and their surrounding structures, including extracellular matrix and tissues of target organ were observed under electron microscope. Foot-like processes with abundant microfilaments extended from one side of the surface of cancer cell were found. The microfilaments were lost with the disappearance of foot-like processes. It hinted that there might be some relationship between the presence of microfilaments and the movement of cancer cells. Around the foot-like processes of infiltrating cancer cell, the local basal lamina always disappeared, and a zone of amorphous matrix was shown. It may result from the action of collagenase. Sometimes the basal lamina may reappear, even on the surface of metastating cancer cell. No direct evidence of destruction of smooth muscle cell by the cancer cell was found. The atrophy and degeneration of smooth muscle cells may be the changes indirectly caused by the infiltrating cancer cells.