Omental cyst torsion is a clinical manifestation of omental cysts. Omental torsion refers to the twisting of the greater omentum along its longitudinal axis and causes its blood circulation to become impaired. It is generally classified as primary or secondary. The torsion is often clockwise and can be twisted multiple times. How to check for torsion of omental cysts? Gastrointestinal barium meal X-ray can reveal small bowel displacement and compression signs, which are not easily distinguished from mesenteric masses. Dermatomal cysts are occasionally seen as calcifications or structures such as teeth and bone. Ultrasound helps to determine whether the cyst is unicompartmental or multicompartmental, but it needs to be differentiated from mesenteric cysts, retroperitoneal cysts and ovarian cysts, which are seen on ultrasound to move up and down with breathing and the small intestine to move to the retroperitoneal wall. Intravenous pyelogram helps to differentiate from retroperitoneal cysts. CT scan is best for exact localization, but the source of the cyst is not easily identified by CT either. Abdominal arteriography is also available and can show images of the greater omental artery and its branches extending and encircling the cyst. Surgical exploration is often required for final diagnosis. Omental cysts (omentalcyst) are rare, accounting for only about 5% of omental disease, and their incidence is much lower than that of mesenteric cysts, with a ratio of about 1:5. Omental cysts are located between the two layers of the omentum and are divided into true cysts and pseudocysts. Clinical manifestations vary depending on the size of the cyst and the presence or absence of complications, and they are categorized into 4 types: 1. abdominal mass type: a large mobile cystic mass without pressure pain is clearly palpated in the abdomen, which may be accompanied by vague pain or cramping in the abdomen. 2, pseudo-abdominal fluid: only seen in giant large omental cysts, the abdomen gradually increases, the whole abdomen is inflated, the mass cannot be clearly palpated, and the fluid wave tremor is obvious, but there is no mobile turbid sound. 3.Incognito type: mostly small cysts, which are found accidentally during abdominal surgery. 4.Acute abdominal type: when the cyst is complicated by torsion, internal bleeding, rupture or secondary infection, it can cause acute abdominal pain and signs of peritoneal irritation. The cyst increases rapidly after intracapsular hemorrhage and is easily infected. Because most cysts are multi-housed, infection is not easily controlled, and patients develop high fever or prolonged low-grade fever with intermittent abdominal pain, depression, poor appetite, wasting, anemia and other signs of wasting toxicity, clinically resembling tuberculous peritonitis. It is easily misdiagnosed. Cyst rupture manifests as sudden severe abdominal pain and increased abdominal distension with obvious anemia and obvious manifestations of bloody or even inflammatory peritonitis after an external blow to the abdomen or when intra-abdominal pressure increases for various reasons, often resembling acute abdominal admission. Cyst torsion occurs in small and medium-sized cysts in the free part of the greater omentum with a wide range of activity, and due to gravity the cyst torsion is clinically manifested as persistent abdominal pain with paroxysmal intensification, accompanied by nausea and vomiting, abdominal masses are found on physical examination, and omental cyst torsion is confirmed after surgery.