Are you still worried about the “polyp” on the colonoscopy report? Are you still wondering what this “polyp” really is? Is it a tumor? Do you need to treat it? Today’s article will take us into the intestinal polyps, let’s unveil the mystery of intestinal polyps.
First of all, what is intestinal polyp?
Intestinal polyps are all elevated lesions on the mucosa of our intestines, commonly known as intestinal lumps, including tumor and non-tumor lesions. Polyps are generally small, slender and curved, irregular in shape, with one end free or both ends attached to the intestinal wall and suspended in the middle, in the form of a bridge. Before the pathological nature is determined, they are collectively called polyps; after the pathological nature is clearly defined, they are directly named with pathological diagnosis according to the location, such as colonic tubular adenoma, rectal carcinoma in situ, colonic inflammatory polyps, etc.
Could it be that some people are more likely to develop intestinal polyps and need special attention?
There are indeed, high-risk groups include: those who have colon cancer or colon polyps in their family members; those who eat high fat, high animal protein, low fiber and fried food for a long time; and those who are older than 50 years old. In addition, the longer you sit, the higher the risk of developing intestinal polyps. It is recommended that these types of people have an annual examination such as electronic colonoscopy, anal finger examination and fecal occult blood to detect colon adenomas with cancer tendency in time. In Europe and the United States, where colorectal cancer is highly prevalent, from the age of 50, it is recommended for all people to have an annual occult blood test on naturally excreted stool and a complete colonoscopy every 5 to 10 years for early detection.
Can polyps become cancerous?
First, we must be clear about the premise that not all polyps are cancerous.
Generally speaking, we would classify intestinal polyps into non-neoplastic polyps and adenomatous polyps (also called neoplastic polyps).
Non-neoplastic polyps are generally not cancerous, mainly including: 1. Juvenile polyps: commonly found in young children, mostly under 10 years old. They often occur in the rectum, are round and spherical, are mostly solitary, and are pathologically characterized by retention cystic cavities of varying sizes, which are a kind of misshapen tumor. 2. Inflammatory polyps: also known as pseudopolyps. Is the ulcer of the colonic mucosa in the healing process of fibrous tissue hyperplasia and ulcer submucosal edema, so that the normal mucosal surface gradually elevated and formed. They are commonly found in chronic ulcerative colitis, amebic dysentery, schistosomiasis, intestinal tuberculosis and other intestinal diseases.
Adenomatous polyps are recognized as precancerous lesions. There are three types of adenomatous polyps, namely tubular adenoma, villous adenoma and tubular choriocapillaris adenoma, among which tubular adenoma is the most common.
How long does it take for a polyp to become malignant and become cancerous?
In terms of age of onset, adenomatous polyps are 5 to 10 years earlier than colorectal cancer. According to the theory of adenoma to cancer development published by Morson in 1976, this time is about 10 years. However, according to some recent literature, it takes at least 5 years to develop from adenomatous polyp to cancer, and the average is between 5 and 10 years. In addition adenomatous polyp carcinogenesis is related to its size, morphology and pathological type. Broad-based adenomas have a higher rate of carcinogenesis than ciliated adenomas; the larger the adenoma, the greater the likelihood of carcinogenesis; and the more villous components in the adenoma structure, the greater the likelihood of carcinogenesis. The specific mechanism of transformation from adenoma to cancer is not known, but from the perspective of molecular biology, the accumulation of multiple mutations in oncogenes (e.g., APC gene, K-ras gene, etc.) and oncogenes in colonic mucosal cells forms the biological basis of pathological changes.
There are also some special types of adenomatous polyps: flat polyps and lateralized developmental polyps.
These are adenomas that are flat or slightly elevated on the surface of the colonic mucosa and have an adenomatous component no more than twice the thickness of the surrounding normal mucosa. It has been reported that the proportion of flat adenomas with severe heterogeneous hyperplasia exceeds that of the usual raised polyps. The abnormal expression of p53 and p21 in flat adenomas suggests that the biological behavior of small flat adenomas of the colon is different from that of polypoid adenomas of the colon. The larger the size of colonic polypoid adenoma, the more obvious its malignant tendency. However, flat adenomas may become malignant at an early stage and become flat-type early colorectal cancer.
It refers to a type of flat elevated lesion originating from the colonic mucosa, which rarely invades the deeper layers of the intestinal wall, but mainly spreads laterally and superficially along the mucosal surface,
It is also called creeping tumor and precancerous lesion. At the early stage of growth, the mucosal surface is only slightly congested, rough or small granular elevation because there is no obvious difference between it and the surrounding mucosa, so it is often missed under endoscopy. However, mucosal staining with indigo carmine or methylene blue can help to improve the diagnosis rate. Some dynamic studies have shown that their benign lesions can develop into progressive colorectal cancer within 3 years, so early diagnosis and treatment of LST can reduce the risk of colorectal cancer.
So, what should we do if polyps are found?
In clinical work, we generally decide the treatment plan according to the size, number, presence of complications and pathological nature of intestinal polyps.
1, small polyps are usually removed during colonoscopy and sent for pathological examination.
2.Adenomas with diameter >3cm, especially villous adenomas, should be surgically removed: those below the peritoneal fold should be removed through the anus, while those above the peritoneal fold should be removed openly or under laparoscopy.
If the adenoma penetrates the mucosal muscle layer or infiltrates the submucosa, it is invasive cancer and should be treated according to the treatment principle of colorectal cancer. If the adenoma malignant lesion does not penetrate the mucosal muscle layer, does not invade the small blood vessels and lymph, has a good differentiation degree, and has no residue on the cutting edge, it is not necessary to perform surgery after removal, but should be closely observed.
4, inflammatory polyps to treat the primary intestinal disease, inflammatory stimulation disappears, polyps can disappear on their own; proliferative polyps symptoms are not obvious, no special treatment.