This type of astrocytoma is a WHO grade III astrocytoma. Histologically, astrocytes are densely packed, with variable differentiation, marked nuclear anomalies, and nuclear schizophrenia is more common; the tumor tissue has increased vascularity and proliferation of vascular endothelial cells. Mesenchymal astrocytoma is a transitional tumor with a high degree of malignancy in some cases, and the average survival of patients is only 2-3 years despite systematic treatment. Clinical manifestations Adults often start with epilepsy and gradually develop paralysis, aphasia, and mental changes, followed by an increase in intracranial pressure. In children, the increase in intracranial pressure is usually the first manifestation. Symptoms of astrocytoma vary depending on the site of growth and the degree of malignancy. The most common symptoms are headache and vomiting. In infants and young children, the most common symptoms are paroxysmal crying, head scratching, head banging, or irritability. Patients with optic nerve glioma and combined hydrocephalus may experience vision loss or even blindness. Infants and children may also develop cranial enlargement. Tumors of the cerebral hemispheres in children have an epilepsy incidence of 20-50%, while tumors of the cerebellum have an incidence of 5%. Tumors of the posterior cranial fossa may present with forced head position or forced body position, unstable walking and ataxia. Tumors in the functional areas of the brain may manifest as limb paralysis and weakness as well as aphasia. Children with highly malignant tumors, combined hydrocephalus, and necrotic cystic tumors often have a short history and progress rapidly, making them susceptible to sudden death. Because infants cannot express their discomfort clearly, many low-grade malignant tumors are already in advanced stage when they are found, which manifests as huge tumors or cystic changes, high cranial pressure or hydrocephalus, or even blindness, cachexia, brain herniation crisis and coma in some children, which makes the treatment more difficult and affects the prognosis of children. Auxiliary examination 1.Cranial X-ray: mainly for the separation of cranial suture and increase of finger pressure mark. If the tumor is located on the surface of cerebellar hemispheres, thinning and erosion of occipital scales on the affected side can be seen, and 4.3% of our group have tumor calcification spots. 2. Ventriculography: In addition to symmetrical enlargement of lateral ventricle and third ventricle, forward flexion of the conduit and displacement of the fourth ventricle to the healthy side are the characteristics of cerebellar hemisphere tumor. 3.Check: Low density shadow in cerebellar hemisphere or midline can be seen. Grade I astrocytoma has no post-injection enhancement, while grade II-III can have enhancement. Some of them have multiple hypodensities in high density (i.e., the capsule is within the tumor), and some of them have high density nodules at the edge of the hypodense area (i.e., the tumor is within the capsule), and this sign is often helpful for preoperative characterization. Treatment and prognosis For more limited cases, such as astrocytomas located in the anterior frontal lobe, the prefrontal lobe can be resected to include the tumor. For other sites, only a major or partial resection of the tumor is possible, supplemented by decompressive surgery. After surgery, radiotherapy and immunotherapy are applied. Most cases have poor healing.