Ultrasound presentation of a case of duodenal intestinal polyp Patient female, 31 years old. She was admitted to the hospital with black stool with dizziness and weakness for more than 1 month. Examination: abdomen flat and soft, no obvious pressure pain, anemic appearance. Gastroscopy showed: duodenal polyp. Routine ultrasonography: a nodule-like echogenicity was seen in the lumen at the beginning of the descending duodenum, with a clear outline, smooth edges and internal isoechoic, and scattered blood flow signal and arterial blood flow spectrum were detected. The nodule moved up and down with duodenal peristalsis, and diffuse intestinal lumen gas was seen around the nodule. Ultrasound diagnosis: duodenal polyp-like lesion. Pathological diagnosis: duodenal adenoma. Discussion: Duodenal adenomas are rare. They occur in the posterior wall of the duodenum at the junction of the first and second segments of the duodenum. They are solitary, polypoid, with a tip, varying in size from 0.5 cm to 6 cm in diameter, and on light microscopy are heavily proliferating and well-differentiated Brunner’s glands with smooth muscle fibers in between. It is more common in males. It can occur at all ages and can cause black stool or duodenal obstruction. Ultrasound diagnosis experience: 1, due to intestinal lumen gas interference, in the supine position when the display is not clear, can be used left and right oblique position or semi-sitting position, so that the intestinal lumen gas displacement, change the transmissive window. 2.Pressure probe, so that the distance between adenoma and probe is shortened, which is conducive to the observation of adenoma. 3.Dynamic observation of intestinal cavity contents, especially when the intestinal cavity gas passes through the periphery of adenoma, shows that the gas passes through the periphery of adenoma intermittently or diffusely, and locates the adenoma in the intestinal cavity. 4. With the peristaltic movement of the intestinal tube, the adenoma can move up and down, so that the adenoma can be judged to have a tip. The adenoma is mainly composed of a large number of hyperplastic Brunner’s glands, which are isoechoic. 6.The blood supply inside the adenoma can be observed by applying Doppler. 7.Ultrasound diagnosis of intestinal polyps is superior to other imaging diagnoses. In conclusion, conventional ultrasound is superior in the localization of duodenal adenoma, internal echogenicity and determination of the tip.