Low-grade malignant tumors refer to tumors with relatively low malignant degree, and the more common ones are ovarian granulosa cell tumor, giant cell tumor of bone, oligodendroglioma and so on. 1. Ovarian granulosa cell tumor: it is a relatively rare tumor which is easier to recur. Patients will have more obvious symptoms of pubic bleeding and menstrual disorders, as well as pelvic swelling and enlarged uterus. 2. Giant cell tumor of bone: it is a benign tumor originated from bone, which is most common in people between 20 and 40 years old. Patients usually have a history of chronic low back pain, which is manifested as localized pain and accompanied by symptoms of pressure on nerves, spinal cord and neighboring organs. 3. Oligodendroglioma: mostly benign tumors, slow-growing tumors, calcified plaques can often be seen within the tumor, clinical manifestations are mostly localized paralysis. The clinical manifestations are mostly localized paralysis. After the clinical appearance of malignant tumors, we need to make a comprehensive diagnosis according to the type and severity of malignant tumors, and carry out the correct treatment under the guidance of the doctor, and make timely review in the later stage.