[Electron microscope study of colon cancer]

24 cases of the carcinoma of large bowel were studied electronmicroscopically. Ultrastructural features of tumour cells of various differentiation were compared. Besides epithelial cells, myofibroblast-reaction, observed in the stroma of tumours and considered as a local immune reaction caused by invasive cancer cells is also dealt with. It was also noticed that myofibroblasts develop from the fibroblasts of the ground substance of the colonic mucosa.