Colon polyps are very common and affect about 30% to 50% of adult population. These growths are benign but may increase the risk of colon cancer. There are different types of colon polyps but in this article we will focus on tubular adenoma polyps.
What are Polyps?
A polyp is abnormal growth of tissue that projects from the mucus membrane. It may occur anywhere in the body but most commonly develops in the colon, uterus, cervix, nose, urinary bladder and stomach. Although polyps are benign, they have to be removed as soon as detected as left untreated they may lead to cancer. This is especially true for colon polyps.
What are Colon Polyps?
Colon polyps usually do not produce any symptoms but occasionally may cause rectal bleeding, blood in stool, changes in bowel movement and pain. Depending on the shape, colon polyps can be penduculated or sessile. Penduculated polyps grow on long, thin stalks and have mushroom-like appearance. Sessile polyps grow directly on the surface of colon.
Since they are often asymptomatic, colon polyps are usually discovered incidentally during a colonoscopy. Colon polyps are common in people over the age of 50 and those who have a family history of colorectal cancer.
Types of Colon Polyps
There are four types of colon polyps. The most common ones are adenomateous and hyperplastic polyps. Hyperplastic polyps are small growths and tend to develop in the rectum. They rarely become cancerous but are usually removed to be examined under a microscope as they cannot be easily distinguished on appearance.
Adenomateous polyps are most common type of colon polyps and definitely pose a risk of colon cancer. There are three types of adenomateous polyps, villous, tubular and tubulovillous. Among them, tubular adenoma has the lower risk of turning into malignant while villous adenomas have the highest chance of becoming colon cancer.
Inflammatory polyps, also known as pseudopolyps or false polyps are not actually polyps but form in response to the chronic inflammation of the walls of the colon. They do not increase the risk of colon cancer but have to be biopsied to rule out malignancy. This type of colon polyps is common in people with inflammatory bowel disease.
The fourth type of colon polyps is the malignant polyp that contains precancerous or cancerous cells.
Tubular Adenoma Polyps
Tubular adenoma polyps are the most common and the least serious type of adenomateous polyps. These polyps have cells arranged in tubules that can be of different size. Tubular adenoma polyps are usually benign. However, as they increase in size the risk of colon cancer increases too. Tubular adenoma polyps are most commonly pendculated but as they grow larger they may develop more villous elements and become sessile thus increasing the risk of colon cancer.