Small intestinal adenoma

　　One, etiology of the disease

　　Intestinal adenomas mostly occur in the duodenum and ileum, with less occurrence in the jejunum. They generally originate from the intestinal mucosal epithelium or glandular epithelium, often protruding into the intestinal lumen, and can be solitary or multiple. They often have a pedicle, and the free end usually points to the distal end. Adenomas vary in size, with small ones only a few millimeters in diameter and large ones up to 3 to 4 cm.

　　Second, Pathogenesis

　　Intestinal adenomas, like colorectal adenomas, can be divided into three types according to their histological structure: tubular adenoma, villous adenoma, and mixed adenoma.

　　1. Tubular adenoma

　　Also known as adenomatous polyp or polypoid adenoma. It occurs most frequently in the duodenum (41.3%), followed by the ileum (34.3%), and less frequently in the jejunum (22.3%). It is mostly solitary, but it can also be multiple. Multiple cases may be concentrated in a segment of the intestinal tract or the entire small intestine, even the entire gastrointestinal tract. This type of adenoma is polypoid, most of which have a pedicle. Statistics show that 50% of cases of familial colorectal polyps can be accompanied by intestinal adenomas. Many cases are asymptomatic, and those with symptoms often have bleeding, and it can also cause intussusception.

　　2. Villous adenoma

　　Also known as papillary adenoma. Less common than tubular adenoma, it occurs most frequently in the duodenum, but it also accounts for only 1% to 3% of duodenal tumors. It decreases gradually from the duodenum to the distal intestinal tract. The size is larger than that of tubular adenoma, ranging from 0.5cm to 8.5cm, but most of them are

　　3. Mixed adenoma

　　Also known as villous tubular adenoma. The two types of structures coexist, and the biological behavior is between the two types of adenomas mentioned above.

　　1. Gastrointestinal bleeding

　　As the tumor grows to a certain size, erosion of the tumor can cause bleeding due to the rupture of blood vessels on the surface of the tumor.

　　2. Jaundice

　　Adenomas in the duodenal papilla can cause obstructive jaundice due to compression or obstruction of the lower end of the common bile duct.

　　Anemia and intussusception are common complications of intestinal adenocarcinoma and are also the main reasons for seeking medical attention. There are also abdominal discomfort, belching, nausea and vomiting, weight loss, bloating, and even diarrhea. Adenomas in the duodenal papilla can cause obstructive jaundice due to compression or obstruction of the lower end of the common bile duct.

　　1. Abdominal pain

　　The most common, about 50% of patients with intestinal adenomas may have varying degrees of abdominal pain, which is mostly located in the middle abdomen or around the umbilicus. Most patients often experience intermittent pain, which can be intermittent and exacerbated, presenting as dull, sharp, or cramping pain. The pain often occurs after eating and can usually be relieved on its own or become less severe. Initially, the pain may not be severe, but it tends to worsen with the progression of the disease. It is often accompanied by bowel sounds and abdominal pain, which is usually due to intestinal dysfunction caused by the tumor, inflammation, ulceration, intussusception, partial or complete obstruction of the small intestine. Among these, intussusception is the most common. Adenomas grow inward, can be pushed forward by intestinal peristalsis and intestinal contents to the distal intestinal loop, causing intussusception. The characteristic is recurrent intestinal obstruction, which can be relieved on its own and present intermittently. Some patients may experience acute attacks of abdominal pain, often requiring emergency surgery to relieve obstruction. However, most patients have had similar episodes of abdominal pain in the past, and the first episode that cannot be relieved still accounts for a small number. Abdominal pain is often not easy to attract attention in the early stage of the disease and is often misdiagnosed as intestinal spasm, enterobiasis, and sometimes even misdiagnosed for several years.

　　2. Gastrointestinal bleeding

　　It is also quite common, about 1/4 of small intestinal adenoma patients may have gastrointestinal bleeding. The tumor expands to a certain volume, and the tumor erosion causes the surface blood vessels of the tumor to rupture, leading to bleeding. Most patients have small bleeding, manifested as intermittent black stools or only positive occult blood in stool, and severe bleeding is rare. Long-term chronic bleeding often causes varying degrees of anemia, with pale or yellowish complexion, emaciation, and some patients may present with acute gastrointestinal bleeding, with dark red or bright red stools, which may also recur, and sometimes may require emergency surgery due to severe bleeding.

　　3. Other

　　There may still be abdominal discomfort, belching, nausea and vomiting, weight loss, abdominal distension, and even diarrhea, etc. Adenomas at the duodenal papilla can cause obstructive jaundice due to compression or obstruction of the lower end of the common bile duct.

　　4. Signs

　　Generally, there are no obvious positive signs. Long-term occult bleeding can cause anemia, PJS patients may have black spots on the lips, mucosa, cheeks, gums, palmar surfaces of fingers and toes, etc. Abdominal localized bulging may occur during intestinal obstruction, with paroxysmal hyperactive bowel sounds or gurgling sounds, and palpable elliptical masses may be felt during intussusception, especially when abdominal pain occurs and the intestinal tract is spasmodic.

　　1. Develop good living habits, quit smoking and limit alcohol. Smoking, the World Health Organization predicts, if people stop smoking, cancer in the world will decrease by 1/3 after 5 years; secondly, do not drink excessively. Cigarettes and alcohol are extremely acidic substances, and those who smoke and drink for a long time are prone to acidic constitution.

　　2. Do not eat too much salty and spicy food, do not eat overheated, cold, expired, and deteriorated food; for the elderly, the weak, or those with certain genetic predisposition to diseases, eat some cancer-preventive foods and alkaline foods with high alkaline content appropriately to maintain a good mental state.

　　1. X-ray examination

　　The diagnostic coincidence rate of routine gastrointestinal barium meal examination is only about 20%, mainly due to the fast peristalsis of the small intestine, where barium may pass over the diseased intestinal segment without being detected; the small intestine is long and tortuous, and the filling is often discontinuous. Taking a large amount of barium may easily cause image overlap, covering the lesion. The use of small intestinal barium perfusion method can increase the diagnostic coincidence rate to 80%-90%. The specific method is to swallow the small intestinal catheter through the mouth, place it at the proximal end of the jejunum, inject dilute barium and gas to form a double contrast of the entire small intestine, and can gradually push the catheter towards the distal side for segmented and step-by-step examination of the small intestine. X-ray images include: filling defects, disappearance of mucosal lines, shadowing and intestinal stricture, and can also show signs of intussusception and multiple segmental lesions.

　　2. Fiberoptic endoscopic examination

　　It is of great significance for duodenal adenomas. Enteroscopy is helpful for the diagnosis of upper jejunum adenomas, and the colonoscopy can pass through the ileocecal valve to send into the ileum 20-30cm, which is helpful for the diagnosis of terminal ileum adenomas.

　　3. Selective superior mesenteric artery angiography

　　It is of great significance for the qualitative and locational diagnosis of gastrointestinal bleeding, which can show the shape and size of the tumor, the regular blood flow and arrangement of the vessels at the adenoma site, regular tumor staining, and clear boundaries.

　　4. Laparotomy

　　For patients who cannot be diagnosed clearly but are suspected of having small intestinal tumors, timely laparotomy exploration should be performed, and small adenoma polyps should not be missed during surgical exploration. If no lesions are found during visual and palpation examination, strong light transillumination examination can be used, and laparoscopic examination can be performed during surgery if necessary, directly observing the small intestinal mucosa, and attention should be paid to the possibility of multiple adenomas in the small intestinal adenomas.

　　1. Foods that are good for small intestinal adenoma patients

　　Diet should be light, eat more vegetables and fruits, and reasonably match the diet, ensuring adequate nutrition.

　　2. Foods to avoid for small intestinal adenomas

　　Avoid smoking and drinking, spicy foods, greasy foods, and smoking and drinking. Avoid cold and raw foods.

　　1. Treatment

　　Small intestinal villous adenomas have a canceration rate of 30% to 50%, and tubular adenomas have a canceration rate of 3% to 8%. Small intestinal adenomas can also occur intussusception and hemorrhage, so surgical resection is recommended for treatment.

　　Adenomas with pedicles can be resected in the shape of a wedge in the small intestinal wall; for larger adenomas without pedicles or those with poor blood supply to the intestinal tract due to intussusception, intestinal resection and anastomosis can be performed. Duodenal adenomas can be resected endoscopically, and after local resection of adenomas in the duodenal papilla, drainage of the common bile duct and pancreatic duct is required. For duodenal villous adenomas that have already become malignant, consideration should be given to pancreaticoduodenectomy.

　　There is still controversy in the treatment of PJS. Some people advocate that no treatment is needed for those without intestinal intussusception and malignancy, arguing that the chance of malignancy in small intestinal PJS is rare, excessive small intestinal resection can cause malabsorption, and most small intestinal intussusception can be spontaneously复位. We believe that it is advisable to adopt active treatment for larger adenomas, and part of the polyps can be removed through fiberoptic gastroscopy and colonoscopy. If abdominal surgery is required, it is advisable to decisively remove larger, tough, or hard polyps with a wide base.

　　2. Prognosis

　　The prognosis after adenoma resection is good. The recurrence rate of duodenal benign villous adenoma after local resection is about 30%, and regular follow-up examinations are required.