Choroidal adenoma is a type of colorectal polyp that is prone to malignant transformation, and patients need to pay high attention to treatment. Any polyp-like lesion protruding from the mucosal surface into the intestinal cavity is called a polyp before the nature of the pathology is determined, and can be classified according to the pathology: adenomatous polyps (including papillary adenomas) are the most common, inflammatory polyps, the result of proliferation of intestinal mucosa stimulated by long-term inflammation, misshapen polyps, others, such as mucosal hypertrophy and hyperplasia to form hyperplastic polyps, lymphoid hyperplasia, carcinoid tissues and other disorders. Clinically, colorectal polyps are more common and have more obvious symptoms. Common intestinal polyps are classified as follows: 1. Juvenile polyps: About 90% occur in children under 10 years old, with boys being more common. They are round or ovoid in appearance, with smooth surface. 90% grow within 25 cm from the anus, most are less than 1 cm in diameter, most have tips, about 25% are multiple, histologically well differentiated and irregularly sized glands, some form cystic expansion, storage mucus, interstitial hyperplasia, and more inflammatory cell infiltration, sometimes with ulcer formation on the surface. Sub-type polyps generally do not occur malignant change. 2, proliferative polyps: Proliferative polyps are the most common type of polyps, also known as saprophytic polyps. Distribution of the distal colon is more, are generally smaller, rarely more than 1 cm in diameter, its shape is a small drop-shaped bump on the mucosal surface, smooth surface, wider base, multiple is also common, the histology of the last polyp is formed by the enlarged and regular glands, glandular epithelial cells caused by increased skin wrinkling serrated, the nucleus is arranged regularly, its size and chromatin content changes are very small, nuclear fission phase is rare. The important feature is the presence of mature cells in both the middle and lower segments of the intestinal glandular crypts. Hyperplastic polyps do not undergo malignant transformation. 3, lymphoid polyps: lymphoid polyps, also known as benign lymphomas, are mostly found in adults aged 20-40 years, but also in children, slightly more in men, mostly in the rectum, especially the lower rectum, most of them are solitary, but also multiple, varying in size, from a few millimeters to 3-4 cm in diameter. The surface is smooth or lobulated or with superficial ulcer formation. Most of them are non-tipped, and when tipped, they are also short and thick. Histologically, they appear as well-differentiated lymphoid follicular tissue, confined to the submucosa and covered with normal mucosa. The center of the growth can be seen, often enlarged, with nuclear schizophrenia, but there is no nuclear schizophrenia in the surrounding lymphocytes, and the proliferating follicles are clearly demarcated from the surrounding tissue. Lymphatic polyps are not carcinogenic. Less common is benign lymphoid polyposis. It manifests as a large number of lymphatic polyps. They are small spherical polyps of 5 to 6 cm in size and most often develop in children. Histological changes are the same as lymphatic polyps. 4, inflammatory polyps: inflammatory polyps, also known as pseudopolyposis, is a long-term chronic inflammation of the intestinal mucosa caused by polypoid granulomas, such polyps are mostly seen in ulcerative colitis, chronic schistosomiasis, amebic dysentery and intestinal tuberculosis and other diseases of the lesion intestine. They are often multiple, mostly small, often less than 1 cm in diameter, and can increase in size in those with longer disease duration. The shape is mostly narrow, long, with a broad tip and distal irregularity. Sometimes they are bridge-shaped, with the ends attached to the mucosa and the middle part free. Histological manifestations are fibrous granulation tissue, epithelial components can also be mesenchymal-like changes, not yet sure. 5, adenoma: colonic adenoma is a benign epithelial tumor of the large intestine. According to the histological structure, there are three types of adenomas, namely tubular adenoma, villous adenoma and mixed adenoma. (1) Tubular adenomas: they are round or oval polyps with smooth or lobed surface, varying in size, but most are less than 1 cm in diameter. 80% have a tip. Histologically, they appear as mostly tubular glands with immature cells distributed at all levels of the gland. There may be varying degrees of mesenchymal changes and sometimes a small amount of papillary hyperplasia. The carcinoma rate is about 1% to 5%. (2) Choroidal adenoma: It is less common than tubular adenoma, and most of them are solitary. Most of them are broad-based, and about 10-20% of them can have a tip. The surface is dark red, rough, or in the form of fluffy protrusions or small nodules, soft and friable, movable when touched, and if hard nodules or fixed when touched, it indicates the possibility of cancer. The distribution is most frequent in the rectum, followed by the sigmoid colon. Histologically, the epithelium grows in a papillary pattern, and the center is vascular connective tissue interstitial, which also grows together with the epithelium, and the epithelial cells grow in a papillary pattern. Its cancer rate is more than 10 times greater than that of tubular adenoma. (3) Mixed adenoma: It is an adenoma with both of the above structures. Its cancer rate is between tubular adenoma and villous adenoma. 6.Familial colon polyps Familial colon polyps with blood in stool belong to the adenomatous polyp syndrome, is an autosomal dominant disease, occasionally seen in people without family history, the whole colon and rectum can have multiple adenomas, most adenomas have a tip, papillary is less common, the number of polyps from about 100 to thousands, from the size of a soybean to several centimeters in diameter, often densely arranged, sometimes in bunches, its tissue structure and general The histological structure is not different from that of a normal adenoma.