During the past 11 years 392 colonic polyps have been removed via the colonoscope in Shizuoka Red Cross Hospital. These polyps were completely studied morphologically and pathologically. There were 359 benign polyps and 33 polyps related to carcinoma.
Among 33 cancerous polyps, the largest number occured in the sigmoid colon followed by the rectum in frequency. Most frequent size of these cancerous polyps were 10-19mm range in diameter but the incidence of malignancy were increased with the advance of polyp size. There were 25 focal cancer (m-cancer), which did not penetrate the muscularis mucosae, and 8 invasive cancer (sm-cancer). No sm-cancer demonstrated 9mm or under in diameter. But the frequency of sm-cancer increased in accordance with the polyp size and no m-cancer noted 40 mm or over in diameter.
In conclusion, since the incidence of carcinoma of the colon is on rise, endoscopic detection and excision of the colonic polyp are most efficient tool to manage of this disease.