Cystic mass in the right lower abdomen may be adenomyosis, malignant tumor of uterus, malignant tumor of ovary and other diseases. 1. Uterine adenomyosis: it is uniformly enlarged and hard, menstruation can be normal, though there will be dysmenorrhea. 2. Malignant tumor of uterus: there is obvious mass in the right lower abdomen, and the enlargement is relatively rapid, which will be accompanied by irregular vaginal bleeding. 3. Malignant tumor of ovary: including anaplastic cell tumor, granulosa cell tumor and immature teratoma, all of which can be palpated in the lower abdomen, and may be accompanied by symptoms such as fatigue, emaciation and irregular vaginal bleeding. 4. Intestinal malignant tumors: Lower abdominal mass will usually appear on one side, and there will be abnormal digestive symptoms, such as abdominal pain, fatigue, black stools and so on. Right lower cystic mass is also seen in other causes, so it is recommended and seek medical treatment, standardized treatment under the guidance of a professional doctor, so as not to delay the condition.