RESUMEN
Twenty specimens of normal colorectal mucosa,juxtacancerous mucosa,and cancerous mucosa were studied with scanning electron microscopy,optical microscopy and histochemical method.It was found that the superficial crypts of normal colorectal mucosa were evenly distributed,orderly arranged,and covered with both absorptive cells and gobler cells;those of juxtacancerous mucosa were usually deformed in various degrees and their goblet cells were increased in number and in size;and the shape of the superficial cells of colorectal carcinoma was dependent on the histologic type of the carcinoma in certain extent.The general features were disordered arrangement and the decrease in number of the cellular microvilli,which indicated the malignant nature of the lesion.It is believed that scanning electron microscope is a useful tool in the diagnosis of colorectal carcinoma