The polyps of the intestine manifest themselves mainly in ‘over 40’ subjects. To the eye they appear as an irregularity of the mucosa, the internal tissue that forms the walls of the colon or rectum, but each polyp, however, can vary in shape, size and mode of growth.
Although not all polyps become tumors, all neoplasms begin as polyps. It is therefore important during colonoscopy to ascertain their characterization and especially the removal of those that have this degenerative potential.
We talked about this topic with Dr. Milena Di Leo, who clarified what polyps exist and which types are more likely to lead to colorectal cancer.
Polyps: types and sizes
Thanks to new technologies and endoscopes, which are becoming more and more advanced in terms of resolution, doctors can identify polyps and in some cases even predict their type. Despite this, the certain method to diagnose and characterize a polyp is the evaluation and histological observation under the microscope: they must then be removed (partially or completely) and analyzed.
Colorectal polyps can be classified by form. About 85% of the polyps are “sessile”, i.e. they have the shape of a dome without stem. On the other hand, 13% are “pedunculate”, like a fungus hanging on the wall of the colon. Finally, only 2% of the precancerous lesions are completely flat.
The shape influences the ease with which the polyps can be visualized by the endoscopist: the pedunculate polyp is generally well visible, while the flat polyp is more complex to identify because it is so thin that it tends to blend with the parts of the intestine. In addition, even the slightest residue of stool in the belly can often make it difficult to see. This explains the importance of a preparation for the intestinal examination that is as accurate as possible, because it allows carrying out a more precise colonoscopy, and visualizing and removing all the observed polyps.
As far as the size is concerned, the polyps can be less than 5 millimeters and even more than 30 millimeters. The smaller the polyp, the less likely it is to be malignant: those larger than 20 millimeters in fact have 10% more chance of having cells modified within them.
Degenerated cells also have different degrees of “modification” from mild dysplasia to cancer. The size, together with the shape of the octopus, affect the methods of removal: generally pedunculate polyps can be removed at one time, often in day hospital, while sessile polyps, especially the larger ones, may require removal in several fragments or a procedure in hospital.
Conventional adenoma and tight polyps: differences
In recent years, numerous studies and evidence have shown that the development of colorectal cancer can also occur from a different type of adenoma, namely the serrated sessile polyp.
75% of colon tumors come from polyps called conventional adenomas (which may be tubular or villous), derived from glandular cells in the colon.
On the other hand, 25% of the tumors come from serrated polyps. These are usually thin, light-colored, unshaped, serrated mucous membranes of the colon, covered with a thin layer of mucus. These characteristics make them not very visible during colonoscopy.
Symptoms that should not be underestimated
“Colorectal polyps do not have specific symptoms – explained Dr. Di Leo. They grow lazy for years and show signs of their presence when they become large or when they have degenerated into cancer. That’s why over 50 years of age is recommended to perform a colonoscopy, the only test that can identify the polyps of the colon-rectum. It is an invasive examination, but today with the help of painkillers and sedatives it is conducted without particular discomfort to the patient.
The age of execution of the first colonoscopy can be anticipated if there is a relative who has had a tumor of the rectum. Given the need to collect further information, in these cases a specialist gastroenterological examination is necessary to establish the right time for the examination and any request for further investigation.