Both men and women have lymphoid tissue and lymph nodes in the normal abdominal cavity. Possible causes of intra-abdominal lymph node enlargement in women include: intra-abdominal infection, lymphoma, metastasis of malignant tumors, mesenteric lymphadenitis and so on. 1. Intra-abdominal infection: lymph nodes are part of the body’s immune system, intra-abdominal infection will stimulate lymphatic tissue reactive hyperplasia, intra-abdominal lymph node enlargement, which can be seen in all kinds of intestinal infections, acute appendicitis, pelvic inflammatory disease, peritonitis and so on. 2. Lymphoma: lymphoma is a malignant tumor originated from lymphatic tissues, therefore, abnormal lymph node enlargement in the abdominal cavity should be considered as the possibility of lymphoma. 3. Metastasis of malignant tumor: malignant tumors of intra-abdominal organs can be metastasized through lymphatic channels and cause enlargement of regional lymph nodes, for example, liver cancer can cause enlargement of hepatic hilar lymph nodes, gastric cancer can cause enlargement of perigastric lymph nodes, colorectal cancer can cause enlargement of peri-intestinal lymph nodes or even inguinal lymph nodes, and so on. 4. Mesenteric lymphadenitis: mesenteric lymphadenitis is one of the common causes of abdominal pain in children, which is related to respiratory tract infection, food stimulation, active immune system of children and other factors. Women should go to the hospital as soon as possible to find out the cause of lymph node enlargement in the abdominal cavity, and then follow the doctor’s instructions to treat accordingly, so as to avoid delaying the condition.