I. Overview Mesenteric lymph node tuberculosis is more common in the pediatric population. It may be part of a complex of intestinal primaries that are quickly resolved, but enlarged and caseous mesenteric lymph nodes may persist for a long time. It may also arise from lymphatic or hematogenous dissemination, often in conjunction with intrathoracic lymph node tuberculosis or systemic cornual tuberculosis. Sometimes mesenteric lymph node tuberculosis is the main manifestation, while tuberculosis in other parts is not obvious, and then it should be diagnosed as a separate case. The majority of pediatric tuberculosis is caused by human type of tubercle bacilli. There are four types of Mycobacterium tuberculosis: human type, bovine type, bird type and mouse type. The human type and the bovine type are the most pathogenic to human body. Clinical manifestations The main symptoms are general tuberculosis poisoning symptoms and local symptoms. The symptoms of chronic poisoning are long-term irregular low fever, loss of appetite, emaciation, easy fatigue, sleep disturbance and emotional instability. Local gastrointestinal symptoms include nausea, vomiting, diarrhea, constipation, abdominal distension, abdominal pain, etc., of which abdominal pain is the most common. Abdominal pain can be a mild dull pain that often persists; however, it is more similar to colic. The abdominal pain is mostly located around the umbilicus or deep in the abdomen, mostly in the left upper or right lower abdomen, and therefore has been misdiagnosed as acute appendicitis and operated on. Visual examination and palpation reveal mild tension and bulging of the abdominal wall, and palpation reveals typical pressure points, often in the right lower abdomen corresponding to the point of appendicitis, or in the left upper abdominal internal zone corresponding to the level of the second lumbar vertebra, i.e., the mesenteric root. Sometimes one or more enlarged lymph nodes, as small as a fava bean or as large as a hand fist, can be palpated with pressure pain. Palpation should be performed early in the morning after a cleansing enema on an empty stomach. The enlarged lymph nodes can sometimes cause compression symptoms: compression of the portal vein can block the reflux and produce ascites and dilated abdominal wall veins; compression of the inferior vena cava can cause lower limb edema; compression of the thoracic duct can cause celiac ascites; compression of the pylorus can cause pyloric stenosis; compression of the intestine can cause incomplete intestinal obstruction. In addition, affected children often have a yellow or white thick tongue, indicating poor digestion. Sometimes it is highly allergic, such as recurrent herpetic conjunctivitis, etc. Examination 1. smear and culture; 2. antibody test of Mycobacterium tuberculosis; 3. antigen test of Mycobacterium tuberculosis; 4. determination of structural components of Mycobacterium tuberculosis; 5. molecular biology test; 6. blood sedimentation test. V. Diagnosis can be decided based on the history of TB contact, positive nodulin test, clinical symptoms, deep abdominal palpation and rectal exploration. Abdominal X-ray can reveal foci of calcification, which is helpful in confirming the diagnosis during the chronic evolution and repeated deterioration of the disease. If necessary, lymph node biopsy with antacid staining should be performed to find Mycobacterium tuberculosis. Differential diagnosis The differential diagnosis should consider chronic or acute appendicitis, according to our treatment of children with mesenteric lymph node tuberculosis has been misdiagnosed as appendicitis most often, even for 2 to 3 years. This is followed by hepatitis non-specific mesenteric lymphadenitis, ascariasis, etc. In addition, occasional differentiation is needed. There are also gastric and duodenal ulcers cholecystitis abdominal lymph node masses should be distinguished from restrictive ileitis lymphosarcoma and other abdominal tumors. Complications It can cause diarrhea and abdominal pain; compression of portal vein by enlarged lymph nodes can block the return flow and produce ascites and dilated abdominal wall veins; compression of inferior vena cava can cause lower limb edema; compression of thoracic duct can cause celiac ascites; compression of pylorus can cause pyloric stenosis; compression of intestine can cause incomplete intestinal obstruction. VIII. Treatment Attention should be paid to nutrition, eating food containing more protein, vitamins and iron. And treat with anti-tuberculosis drugs. If the enlarged lymph nodes compress the abdominal organs and produce corresponding symptoms, and the medical treatment is ineffective, surgical operation can be considered to release the compression. Caseous necrotic lymph nodes can be removed from the caseous material. The rest of the lymph nodes that do not produce symptoms of compression are generally left untreated. The disease is mainly treated non-operatively, but when complicated by intestinal obstruction or peritonitis due to septic penetration of lymph nodes, surgical treatment is required. (1) Infants and children under 13 years of age who have not received BCG vaccination and have a positive tuberculin test; (2) close contacts with open tuberculosis patients (mostly family members); (3) those whose tuberculin test has recently changed from negative to positive; (4) those with a strong positive tuberculin test; (5) those with a strong positive tuberculin test. (5) Children with positive tuberculin test need to use adrenocorticosteroids or other immunosuppressants for a longer period of time. The prognosis of the disease is good after active treatment, and the caseous lesions of lymph nodes can be gradually absorbed and the hard nodes can calcify and heal spontaneously. The symptoms of chronic toxicity can exist for a long time before disappearing. The case of lymph node caseous necrosis and liquefaction, which breaks into the abdominal cavity or outside the abdominal wall and forms a fistula for a long time, is called mesenteric tuberculosis, which is now rare. In cases of combined peritonitis and intestinal tuberculosis, the prognosis is directly related to both diseases.