The intestine is a long hollow tube surrounded by muscle that extends from the stomach to the anus. The portion of the intestine just prior to the rectum is called the colon, and is part of the large intestine. The Mayo Clinic reports that colon polyps are noncancerous masses that form along the inside of the colon. Some polyps left untreated may turn into cancer. The several different types of colon polyps differ based upon the cell types that make up the polyp.
Adenomatous Colon Polyps
These are the most serious type of polyps, which may eventually turn into cancer, according to Merck Manuals, an online medical library. CBL Pathology Inc., a company specializing in pathology, adds that 95 percent of all colon cancers arise from adenomatous polyps. Merck Manuals reports that adenomatous polyps are generally one of three different subtypes: tubular, tubulovillous or villous adenomas. The risk of colon cancer developing is highest when a villous adenoma is discovered, less for tubulovillous adenomas and the lowest for tubular carcinomas. However, the risk of cancer also is proportional to polyp size, with a larger polyp indicating a higher risk.
Juvenile Colon Polyps
Juvenile colon polyps affect a child's colon. Merck Manuals notes that colon polyps often grow bigger than the blood supply can maintain, causing the polyp to die. These polyps often "autoamputate," meaning they fall off sometime after puberty. Treatment usually is not required, but may be necessary to stem possible rectal bleeding.
Hyperplastic Colon Polyps
Hyperplastic colon polyps are the most common type accounting for 90 percent of all colon polyps, according to CBL Pathology Inc. Hyperplastic colon polyps usually are not harmful, and generally do not develop into colon cancer. Rarely, some hyperplastic colon polyps may become cancerous, but only in people with a history of, or a family member with, multiple hyperplastic polpys.
Inflammatory Colon Polyps
Inflammatory colon polyps grow as a result of inflammatory conditions of the colon, such as ulcerative colitis or Crohn's disease.
