Today’s article will take us into the intestinal polyps and let’s unravel the mystery of intestinal polyps.
First of all, what is an intestinal polyp?
Intestinal polyps are all elevated lesions on the mucosa of our intestines, commonly known as bumps on the intestines, 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 shape 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.
Why did polyps grow in the good intestine? Why do polyps grow in the intestine?
The formation of intestinal polyps are mainly due to the following reasons.
1, infection: inflammatory polyps are associated with chronic inflammation of the intestine.
2, age: the incidence of colorectal polyps increases with age.
3, embryonic abnormalities: juvenile polyposis is mostly misshapen tumors, which may be related to abnormal embryonic development.
4, lifestyle habits: low-fiber diet is associated with colorectal polyps; smoking is closely related to adenomatous polyps
5, genetic: the occurrence of certain polyposis is related to genetics, such as familial non-polyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP), 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: family members with colon cancer or colon polyps; those who eat high fat, high animal protein, low fiber and fried foods 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 less likely to become cancerous and mainly include.
1, juvenile polyps: commonly found in young children, mostly under 10 years old. They often occur in the rectum, are round in shape, mostly solitary, and are pathologically characterized as a misshapen cystic cavity of varying size.
2, inflammatory polyps: also known as pseudopolyps. Is the ulcer of the large intestinal mucosa in the healing process of fibrous tissue hyperplasia and inter-ulcerative 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 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 unknown, 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.
Flat polyps
refers to adenomas that are flat or slightly elevated on the surface of the colonic mucosa and whose adenomatous component is 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 in the colon is different from that of polypoid adenomas in the colon. The larger the size of 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.
Lateral developmental colon polyp (LST)
They rarely invade the deeper layers of the intestinal wall, but mainly spread laterally and superficially along the mucosal surface, also known as proliferative tumors and precancerous lesions. At the early stage of growth, there is no obvious difference between them and the surrounding mucosa, and only slightly congested, rough or small granular elevations can be seen on the mucosal surface, so they are often easily missed under endoscopy. However, mucosal staining with indigo carmine or methylene blue can help to improve the diagnosis rate. A dynamic study has shown that 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.
There are two polyps in the picture above, do you see both of them? Then, if polyps are found, how should we deal with them? In clinical work, we usually 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 >3cm in diameter, especially villous adenomas, should be removed surgically: below the peritoneal fold through the anus, 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 an invasive cancer and should be treated according to the principles of colorectal cancer treatment. If adenoma malignant does not penetrate the mucosal muscle layer, does not invade small blood vessels and lymph, has a good degree of differentiation, and has no residue on the cut 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 stimuli disappear, polyps can disappear on their own; proliferative polyps symptoms are not obvious, no special treatment.
Who are the people with high prevalence of intestinal polyps?
Family members have colon cancer or colon polyps; long-term eating high fat, high animal protein, low fiber and fried food; age greater 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.
In conclusion: intestinal polyps are not a major disease, but they should not be ignored. We should neither ignore nor be overly alarmed by polyps in colonoscopy reports. The right thing to do is to consult your doctor and ask if you need a biopsy or treatment, and follow his advice. Of course, for recurrent polyp growth, one must pay attention to the possibility of genetic disease and also to the presence of other diseases. For patients who are found to have intestinal polyps but do not need special treatment for the time being, they must pay attention to their daily diet and have regular colonoscopies.