Rochester General Hospital
Colorectal Polyps
Polyps are abnormal growths and can develop on the lining of the intestine. Some are flat, others have cluster-like forms. Most are benign (non-cancerous), but many can become malignant (cancerous). It is for this reason that physicians will remove them once they are found.
There are several types of polyps and these are defined by size and how the cells look under a microscope.
Benign Polyps
- Hyperplastic
- common
- small, approximatly the size of a pea
- no potential to become cancerous
- Inflammatory
- small
- inflamed cells commonly associated with disease such as Ulcerative colitis or Crohn's disease
- Hamartema
- small
- associated with genetic diseases (inhereted polypsyromes)
- numerous, scattered throughout the colon
Precancerous Polyps (pre-malignant) These polyps are also called adenomas
- Tubular
- can grow to several inches in diameter
- made of tube shaped cells
- are pre-malignant (can turn cancerous)
- 20% can become cancerous because of villous cells
- Villous
- can grow to 4-5 inches in diameter
- made of villous cells (cluster of fingerlike projections)
- pre-malignant
- up to 40% can become cancerous
Cancerous Polyps
- Carcinoma in situ
- polyp contains cancer cell (malignant)
- the cancer cells are contained in the polyp and have no pontenial to spread to other organs
- Adenocarcinoma
- most common cancer of the colon
- has the potential to spread to other organs
It is obvious to see why physicians will remove polyps when they are found. There is a hereditary condition called familial polyposis in which there is a large number of polyps in the colon. The polyps are too numerous to be individually removed, therefore, physicians recommend that the entire colon be removed to prevent cancer.
