Colonic polyps and polyposis

Polypoid projections of mucosa protruding into the colonic lumen are called colonic polyps. They include various types of neoplastic or non-neoplastic lesions. In 1982, pathologists of the National Colorectal Cancer Cooperative Group proposed a unified classification standard for China, dividing polyps into 5 categories as shown in Table 1. In a survey of 2755 cases of colonic polyps by the Zhejiang Provincial Colorectal Cancer Cooperative Group (1978), neoplastic polyps accounted for 72.3%, while Shinya in the United States reported 82.7%. The proportion in China is slightly lower, possibly because the data include a relatively high proportion of schistosomal polyps and a relatively lower proportion of neoplastic polyps.