OVERVIEW
Colorectal polyp is a general term for all superfluous organisms protruding into the intestinal lumen, including neoplastic and non-neoplastic. Neoplastic polyps are true tumors with proliferation of epithelial cells in the colorectal mucosa, which are collectively called adenomas, and can be divided into adenotubular, villous, and mixed categories according to their histological features and biological behaviors; they are closely related to carcinogenesis, with varying degrees of malignant changes, and are precancerous lesions or states. While non-tumor polyps have less relationship with carcinogenesis. Because these two kinds of polyps are not easy to distinguish clinically, the so-called colorectal polyps in the clinic do not indicate the pathological nature of the polyps, usually clinicians say polyps are mostly non-neoplastic polyps, therefore, polyps are often used as the initial diagnosis, and then further classified after clear diagnosis by pathological examination, which is of greater clinical significance for the diagnosis of adenomas.
Etiology
Domestic report to adenomatous polyps is the most common, while some foreigners reported that hyperplastic polyps are the most common, and its incidence rate is as high as 25% to 80%; in adults, the incidence rate of hyperplastic polyps is at least 10 times higher than that of adenomas, but some scholars have found that adenomas are 3 times more common than hyperplastic polyps in colonoscopy.
1. Mechanical injury and stool irritation
Crud and foreign matter in stool and other factors can cause intestinal mucosal damage or long-term stimulation of intestinal mucosal epithelium.
2. Dietary factors
Dietary factors have a certain relationship with the formation of rectal polyps, especially the interaction between bacteria and bile acids may be the basis for the formation of adenomatous polyps.
Studies have shown that changes in total bile acids and bile acids in the stool may be associated with the volume of colonic and rectal polyps and the severity of epithelial tissue transformation. In addition, high fiber diet, the incidence of colonic and rectal polyps is lower.
3、Inflammatory stimulation
Long-term chronic inflammation of the rectal mucosa, such as ulcerative colitis, amoebic dysentery, intestinal tuberculosis, non-specific proctitis, advanced schistosomal enteritis, etc., can cause polypoid granulomas on the intestinal mucosa.
4. Gene mutation and genetic factors
Current research at home and abroad shows that the formation of adenomatous polyps is closely related to gene mutation and genetic factors. For example, intestinal adenomatous polyp gene (APC) is an oncogene, and gene mutation can cause familial adenomatous polyp lesions and colon and rectal cancer.
Classification
There are many ways to classify colorectal polyps, and according to the number of polyps, they can be classified as single or multiple, but the one that is widely used in China and abroad is based on Morson’s histologic classification, which classifies colorectal polyps as neoplastic, dysgerminomatous, inflammatory, and hyperplastic (Table 1). The greatest advantage of this classification is that colorectal polyps are collectively referred to as adenomas, whereas other non-neoplastic polyps are collectively referred to as polyps. Evolution to adenoma. This classification provides a clear distinction between the pathologic nature of colorectal polyps and provides greater guidance for treatment.
Symptoms
Most colorectal adenomatous polyps have an insidious onset, without any clinical symptoms, a few manifested as changes in bowel habits, blood and mucus in the stools, loose stools, increased frequency, and varying degrees of abdominal discomfort, occasional abdominal pain, lethargy, anemia and other systemic symptoms, and very few have a mass that prolapses from the anus during bowel movements. Cases with a family history are often suggestive of the diagnosis of polyps. Some typical symptoms outside the intestinal tract often suggest the possibility of polyposis, some patients often due to symptoms outside the intestinal tract, must not be ignored. Because of the few clinical symptoms of this disease, it is easy to ignore or miss the diagnosis, therefore, the diagnosis of colon polyps should first improve the understanding of this disease, where the cause of blood in the stool or gastrointestinal symptoms are not clear, especially in middle-aged and elderly men over 40 years of age, attention should be paid to make further examination, in order to improve the discovery rate of colorectal polyps and the rate of confirmation of the diagnosis.
Examination
1. Laboratory tests
Fecal occult blood test: its diagnostic significance is limited, with more false negatives, while a positive test may provide clues for further examination.
2.Auxiliary examination
(1) X-ray examination X-ray barium enema can sensitively detect colorectal polyps through the filling defect of barium, but it often fails to correctly classify and characterize the lesions.
(2) Endoscopy can not only observe the microscopic lesions of the colorectal mucosa under direct vision, but also determine the nature of the lesions through tissue biopsy and cytological brushes, so it is the most important means of discovering and confirming the diagnosis of colorectal polyps.
Diagnosis
Based on clinical presentation, X-ray examination, and endoscopy, polyps are detected in 3 ways. The most common is when a patient comes to the clinic with bowel dysfunction (e.g., irritable bowel syndrome) or rectal bleeding and finds it by chance; the second is when it is found during a census of an asymptomatic population; and the third is when a polyp is large and is detected by a patient who comes to the clinic with blood in the stool or with symptoms of the polyp itself. The third way of detecting polyps is very limited, as polyps often have no clinical signs.
Treatment
1. General treatment
Endoscopic high-frequency electrocoagulation polypectomy, laser or microwave resection is the main treatment.
2. Surgical treatment
Patients with polyposis can be treated with a combination of endoscopy and surgery, which can achieve the therapeutic purpose and maintain the normal function of the colon.
3. Regular follow-up
Since colorectal polyps, especially adenomatous polyps have been recognized by scholars as pre-cancerous lesions or states, regular follow-up of patients with intestinal polyps.