Omental tumor

　　First, etiology

　　Omental tumors can be divided into primary and secondary types. Primary omental tumors have a wide range of origins different from mesenteric tumors, 60% of which come from smooth muscle, including leiomyoma and leiomyosarcoma, and other benign tumors such as lipoma and neurofibroma are very rare. Primary omental tumors refer to tumors occurring in the omentum itself, rather than due to infiltration, implantation, or metastasis of tumors from other organs in the abdomen or outside the abdomen. If classified according to the nature of the tumor, they are generally divided into benign tumors and malignant tumors.

　　1. Benign tumors:Smooth muscle tumors and lymphangiomas are more common, and rare benign tumors include teratoma, fibroma, lipoma, hemangioma, mesothelioma, mucinous cystadenoma, and inflammatory pseudotumor, etc. Omental cysts are mostly benign lesions, and their source is usually congenital, with cystic dilation of lymphatic vessels. A few are due to local expansion after lymphatic obstruction, resulting in cyst formation. Other rare causes include trauma, parasitic infection, etc. Some scholars classify omental cysts according to their content into hemolytic cysts, chylous cysts, serous cysts, cysticercosis cysts, dermoid cysts, and cysts formed after tumor degeneration, necrosis, and liquefaction.

　　2. Malignant tumors:Primary malignant tumors originating from the omentum are rare, and most are sarcomas, such as leiomyosarcoma and liposarcoma. Other types include malignant lymphoma and malignant vascular endothelioma, etc. More common are malignant tumors that metastasize to the omentum, such as gastric cancer, liver cancer, ovarian cancer, colon cancer, and other intra-abdominal malignant tumors that can metastasize to the omentum. The mode of metastasis can be through blood or lymphatic circulation, or by the implantation of cancer cells after falling off the omentum, or by direct infiltration and spread of the tumor.

　　Second, pathogenesis

　　1. Omental tumor:Most are benign, 40% of omental neoplasms are malignant, and these malignant tumors mainly cause local infiltration and peritoneal implantation, rather than distant metastasis, but they can be fatal due to invasion of major organs.

　　31: Mainly include smooth muscle sarcoma, rhabdomyosarcoma, liposarcoma, hemangiopericytoma, fibrosarcoma, and mucinous adenocarcinoma; benign tumors include lipomas, leiomyomas, hemangiomas, and neurofibromas, etc.

　　29. Secondary omental tumors:Mostly derived from the metastasis of intra-abdominal malignant tumors (such as gastrointestinal, peritoneal, retroperitoneal tissue, or malignant tumors in the uterus and ovaries), the most common source is the malignant tumors of gastric cancer and ovaries, and rare cases of teratoma of the omentum can be encountered, mostly being dermoid cysts.

　　25. Complications caused by malignant omental tumors:Including general emaciation, anemia, malignant pleural effusion, cachexia, ectopic hormone syndrome, tumor metastasis, etc.

　　23. Complications during treatment:(1) Intestinal obstruction: mainly manifested as abdominal pain, distension, cessation of anal exhaust and defecation, vomiting, etc. (2) Hemorrhage: often leads to a rapid heart rate, decreased blood pressure, cold sweat, reduced urine output, and even shock, a series of clinical symptoms that often threaten life.

　　Secondary tumors are often found during exploratory surgery for other organ lesions or at the same time as recurrent tumors in the late stage, with the prominent feature of abdominal distension, and most patients have abdominal dull pain and distension.

　　18. Abdominal pain:When the tumor is large, most patients have symptoms such as abdominal dull pain, fullness, and gastrointestinal dysfunction, 65% of patients may have abdominal pain, which is worse when lying down and less when standing, and a few cases may have nausea.

　　16. Abdominal palpation:A mass can be felt, and the primary tumor characteristic is the gradual enlargement of the abdomen, and a mass in the abdomen can be found during physical examination.

　　14. Ascites:Advanced malignant tumors can produce ascites, which may be hemorrhagic or non-hemorrhagic, and percussion may show mobile dullness.

　　12. Weight loss:Patients with malignant tumors have obvious systemic symptoms, weight loss, and may be accompanied by general emaciation, anemia, or cachexia.

　　8. Do not eat contaminated food, such as contaminated water, crops, poultry, fish eggs, and moldy food, and eat some green organic food (not green vegetables), especially to prevent diseases from entering the body through the mouth.

　　7. Strengthen physical exercise, enhance physical fitness, exercise more in the sun, and sweating can help expel acidic substances from the body through sweat, avoiding the formation of an acidic constitution.

　　6. Perform a cancer screening examination once a year proactively. Everyone has cancer gene cells in their bodies, but not everyone will get cancer. However, when your immune function is low, normal cells decrease and cancer cells increase. People with a family history of tumors are recommended to have a physical examination twice a year; healthy people are advised to have a physical examination once a year.

　　It is not specific, blood routine examination may show anemia, and abdominal fluid examination is mostly hemorrhagic exudate. Tissue pathology examination should be performed.

　　1. X-ray examination:It is often used to judge the location of omental tumors. If the abdominal X-ray film shows a shadow of a mass in front of the abdominal cavity or if the gastrointestinal barium meal examination finds a mass in front of the intestinal tract and it is not related to the intestinal tract, it should be considered more likely that the mass is an omental tumor.

　　2. B-ultrasound examination:It has a preliminary determination effect on mesenteric inflammatory masses, cysts, or tumors, which helps determine the location of the mass and its nature as cystic or solid, etc.

　　3. CT examination:CT scans can show various images, including masses, lumps of mesentery, infiltrative small nodules, cystic masses, or multiple solitary nodules, which are the best means to determine mesenteric masses. It can not only determine the location of the mass and its relationship with surrounding tissues and organs, but also has a good diagnostic value for mesenteric torsion and vascular infarction.

　　4. Laparoscopic examination:Combined with biopsy, the etiology and nature of the lesion can be clarified.

　　Avoid spicy and刺激性 food. The diet of patients should be light and easy to digest, eat more vegetables and fruits, reasonably match the diet, and pay attention to adequate nutrition. In addition, patients also need to pay attention to avoid spicy, greasy, and cold food.

　　I. Treatment

　　The main treatment method for mesenteric tumors is surgical resection. Primary malignant tumors have a high degree of infiltration and often require the resection of the entire mesentery and adjacent organs; the role of radiotherapy and chemotherapy is not yet clear. Resection of mesenteric tumors can control ascites. If it is a benign tumor, partial resection of the mesentery including the tumor can be performed, and the surgery is not difficult. Benign tumors can achieve curative resection, and there are few reports of recurrence. If the malignant tumor is primary in the mesentery, then a complete mesenteric resection should be performed. If it is a metastatic malignant tumor, then the primary lesion and the metastatic lesion should be resected as much as possible. However, for the surgical resection of primary malignant mesenteric tumors and metastatic cancers, it is often palliative and has a poor prognosis. However, after resection, it can reduce the burden of abdominal tumors, prevent the formation of ascites, and adjuvant radiotherapy or chemotherapy should be given after surgery. In recent years, intraperitoneal chemotherapy and arterial catheterization for intraperitoneal artery chemotherapy or embolization have been advocated. The most fundamental chemotherapy for metastatic mesenteric cancer is to target the primary cancer focus, and its efficacy is consistent with the chemotherapy effect of the primary cancer.

　　II. Prognosis

　　Most patients with benign mesenteric tumors can survive for a long time after surgery, with a 5-year survival rate of up to 75%. The prognosis of patients with benign tumors is good, with no reports of postoperative recurrence. Patients with malignant mesenteric tumors have an average survival period of half a year. Malignant mesenteric lymphoma is treated with radiotherapy and chemotherapy, with a relatively good prognosis.