What Is a Cerebellar Astrocytoma?

Typical fibroblastic astrocytoma grows from the hemisphere of the cerebellum, with early manifestations of cerebellar involvement on one side. The tumor can involve the midline and the four ventricles, block the dense spinal pathways, cause hydrocephalus, and manifest as cranial hypertension. Diffuse astrocytoma often grows from the midline and directly invades the four ventricles. Even the brain stem, clinical ataxia, cranial hypertension signs and cranial nerve palsy.

Cerebellar astrocytoma

Cerebellar astrocytoma is the most common, accounting for 20% of childhood brain tumors and 40% of posterior cranial fossa tumors. It is divided into fibroblastic and diffuse types. In the fibrillar type, the tumor cells are spindle-shaped and scattered in the glial fibers. There are microcapsules and Rosethis fibers, which often form larger cysts, which contain more protein components, and one or more on the cyst wall. A typical nodule. Diffuse astrocytoma grows infiltratingly, and its cellular composition is similar to that of low-grade malignant astrocytoma in the cerebral hemisphere.

Clinical manifestations of cerebellar astrocytoma

Imaging Features of Cerebellar Astrocytoma

On the x-cT image, the fibroblastic astrocytoma generally shows a uniform low-density change, with a large cystic structure, and typical tumor nodules often appear on the cyst wall, which is clearer when enhanced. Diffuse astrocytoma shows equal or low density on x-cT, with unclear borders and uneven enhancement. On the MRI image, the solid part of the two showed a low signal on the T1 image and a high signal on the child image, and the signal of the cyst cavity was determined by the protein content. Signals from bleeding in the cystic cavity may also be present, but are rare. The nodule of the sac wall immediately showed an enhancement effect after the injection of the enhancer. Encapsulation of the entire capsule wall is rare, and once it appears, it can indicate the approximate edge of the lesion. The qualitative diagnosis of astrocytoma by MN is superior to x-cr, which is shown in the following: can show invasive growth; can determine whether the brainstem, cerebellar foot is violated. Low malignant cerebellar astrocytoma rarely spreads cerebrospinal fluid in the early stages of onset, and does not require whole brain, spinal cord MM, and cerebrospinal fluid cytology.

Differential diagnosis of cerebellar astrocytoma

(A) medulloblastoma

The age of onset is small, the damage to the crotch is small, and the damage to the cerebral hemisphere is obvious, and the course of the disease progresses rapidly. Contrast-enhanced CT scan of myeloblastoma is significantly enhanced, and cystic changes and calcification are rare: cerebrospinal fluid cytology can find shed tumor cells,

(Two) small bowel vascular reticuloma

More common in adults, may have a family history, the incidence of children is very low often with erythrocytosis, vertebral angiography common vascular group,

(Three) ependymal tumor

Occurs in the fourth ventricle. Increased intracranial pressure occurs early, cerebellar damage appears late and is mild, and there is often a forced head position. The incidence of calcification in plain CT scans is more than half, and low-density areas of cystic changes can be saved in tumors. Most of the enhancement scans are unevenly enhanced; tumors are located in the center. Surrounded by a low-density edema band.

(D) Cerebellar tuberculoma

There are many tuberculosis exposure to fire, viable tuberculosis lesions in the lungs, general tuberculosis manifestations such as weight loss, low fever, etc. Cerebrospinal fluid examination can show white blood cell increase, and changes in sugar and chloride.

Cerebellar astrocytoma pathogenesis

Tumors are highly differentiated and grow slowly. 60% to 86% of the tumors undergo cystic changes, forming very large cysts, which increases their volume, compresses and shifts the surrounding structures. It is most likely to compress the fourth ventricle and cause obstructive cerebral fluid Symptoms of increased intracranial ratio and further enlargement of the tumor can make the cerebellar subtonsillar hernia enter the spinal canal, which can compress the cervical nerve root and cause a forced head position. It can also press the brain stem to attack the cerebellar crisis, which endangers the life of the cow. In addition, long-term cerebellar compression will damage its function and cause the corresponding cerebellar damage symptoms.

Histopathological diagnosis of cerebellar astrocytoma

The density of the cells is moderate, with unipolar or bipolar morphology, rich in neurofibrils, and continuous with the bipolarity of the tumor cells, so the histological morphology of the tumor is woven or reticulated, or it can be arranged in parallel in waves. shape. The nucleus was stalk-like, spindle-shaped, or oval, without mitosis. The cyst wall is free of tumor cell components.

Treatment : Proton radiation or surgical treatment is preferred for cerebellar astrocytoma.

Proton radiation therapy for cerebellar astrocytoma : precise positioning of radiation through the proton beam can effectively break the cerebellar astrocytoma DNA. In order to kill cancer cells, this is the latest technology in international radiation therapy, and it has been called the preferred treatment for astrocytoma in Europe, America, Japan and other countries. In China, only protons are owned by Zibo Wanjie Cancer Hospital.

Other radiotherapy: The use of Nuori knife or photon knife is also a radiation therapy device for treating cerebellar astrocytoma. How can it be treated as a second proton regimen. Can be treated simply or in conjunction with postoperative radiotherapy.

Surgical treatment: After surgical resection, the prognosis of fibroblastic meliform tumor is quite good. According to most reports, more than 95% of children still survive after 5 years, and the condition is stable. For partial resection, surgery can be repeated or closely followed up. Some people also use radiotherapy to partially resect patients to delay the recurrence time. Although the treatment of diffuse cell tumors is not as good as that of fibroblasts, the 5-year and 10-year survival rates are between 7% and 30%. Due to the diffuse growth of the tumor, it is difficult to remove it completely. It is unclear if the diffuse astrocytoma can be completely resected and the natural course is the same as that of the original fibrous type. Diffuse astrocytoma is long infiltrating, and often undergoes malignant transformation, and it is more likely to spread to the two sub-membrane cavities of the younger sister. Therefore, it is clinically advocated to perform whole-brain spinal cord radiotherapy, but some people have objections. .

Chemotherapy: As an adjuvant treatment of diffuse cerebellar astrocytoma, there is no authoritative conclusion. Given its good curative effect on other low-grade astrocytoma, it is expected to have a certain effect on cerebellar astrocytoma.