Oligodendroglioma and anaplastic oligodendroglioma
Introduction
Introduction to oligodendroglioma and anaplastic oligodendroglioma The oligodendrocyte tumor is an invasive glioma with tumor cell morphology mainly composed of oligodendrocytes. It is divided into two types: oligodendroglioma and anaplastic oligodendroglioma. On the upper side, the frontal lobe is the most common, followed by the parietal lobe and temporal lobe. Compared with astrocytic tumors, the prognosis of patients with oligodendrocytes is slightly better. basic knowledge The proportion of illness: 0.005% Susceptible people: no special people Mode of infection: non-infectious Complications: brain edema dehydration
Cause
Causes of oligodendroglioma and anaplastic oligodendroglioma
Causes:
Molecular biology studies have shown that the occurrence of oligodendrocytes is associated with loss of heterozygosity on the long arm (19q) of chromosome 19.
Pathogenesis:
Less gliomas are located in the white matter, which can be seen in the cortex. The appearance of the tumor is gray-red, soft, and the infiltration range is often extensive. There is a tendency to infiltrate the deep midline structure, such as invasion of the lateral ventricle wall, transparent septum and Thalamic commissure, 40% of the tumor has calcification group, 20% have cystic changes, and the boundary between the brain and the brain tissue is clear, sometimes the pseudo-envelope is visible, some tumors produce mucin-like changes, and aggregate into jelly-like substances.
Under the microscope, the tumor cells expand and grow, the shape is uniform, the shape is small and round, there are few protrusions, the nucleus is round, the mitotic figures are rare, the staining is deep; the cytoplasm is few and translucent or phage acidic, using silver infiltration method (carbonated Silver staining shows that the cells are round, the cytoplasm is stained black and there are few short and short cell bulges. The cells are arranged in strips or sheets, and the blood vessels are rich, with intimal hyperplasia and surrounding connective tissue hyperplasia, malignant. The oligodendroglioma is more round in shape, with a larger nucleus and a lighter staining, more cytoplasm, and more common mitotic figures. Fiber bundles and scattered neuronal cells are common in tumors, 1/2 to 2/3 There are mineralization changes in the calcified spheres or blood vessel walls in the tumor. Some microcapsules can be seen in the tumors, mucinous degeneration and necrosis, astrocyte hyperplasia can be seen at the edge of the tumor, and immunohistochemical staining is found.
Because oligodendroglioma cells contain microtubules instead of glial fibers, GFAP staining of oligodendroglioma cells is negative, with a small amount of GFAP-positive reflex astrocytes, and individual tumor cells can be seen Cerebrospinal fluid is spread, under electron microscope, the tumor cells are densely arranged, the extracellular space is rare, and the cytoplasm is sparsely electronized. It has a honeycomb structure under light microscope, a small amount of ribosome, endoplasmic reticulum and microtubules, etc., and a large number of mitochondria are visible. It has few cell processes and is sparsely electroned. It is distributed around the cell body and contains microtubule structure, but it has no connected structure. Occasionally, it can be found that the poorly developed point-like dense body can be widely seen in the tumor. The intermediate cells of glial cells may represent the differentiation of tumor cells into astrocytes, and the mitotic figures of malignant oligodendroglioma are particularly prominent.
The anaplastic oligodendroglioma also has obvious calcification. The histological morphology of the malignant tumor is similar to that of glioblastoma. The fundamental difference between oligodendroglioma is that the tumor cells are extremely rich and diverse. The proportion of cytokines is increased, the mitotic figures are more common, the vascular endothelium hyperplasia is obvious, and tumor necrosis exists. Very few extracranial metastases can occur, mainly bone, lymph nodes and lungs.
Prevention
Prevention of oligodendroglioma and anaplastic oligodendroglioma
Living habits need to pay attention, it is best to put more effort into the diet, which can also prevent other diseases, the patient itself can also attract certain vitamins. Quit smoking, drink less and drink coffee. Go to bed early and get up early, exercise your body and keep your mind calm.
Complication
Less glioma and dysplasia of oligodendroglioma Complications brain edema dehydration
If surgery is performed, the following complications may occur:
1. Intracranial hemorrhage or hematoma is not related to intraoperative hemostasis. With the improvement of surgical techniques, this complication has been less frequent. The wound is carefully hemostasis and repeated flushing before closing the skull can reduce or avoid postoperative intracranial hemorrhage.
2. Cerebral edema and postoperative high intracranial pressure can reduce intracranial pressure with dehydrating drugs, and glucocorticoids can alleviate brain edema.
3. The loss of nerve function is related to the important functional area and important structure of intraoperative injury. The injury should be avoided as much as possible during the operation.
Symptom
Symptoms of oligodendroglioma and anaplastic oligodendroglioma Common symptoms Sensory disorder Mental disorder Growth slow Focal symptoms Visual impairment Increased intracranial pressure
Most patients with oligodendroglioma grow slowly and have a long course of disease. The average time from symptom onset to treatment is 2 to 3 years. The reported duration is 2.4 to 4.1 years. The longest period is 31 years. The most common symptoms of epilepsy. It is the most common neuroepithelial tumor, and often has epilepsy as the first symptom. It is found in 50% of patients, 85% of patients have seizures, and patients with epilepsy usually have a longer course of disease. Some patients are mistaken for Primary epilepsy has been treated for many years, until the symptoms of increased intracranial pressure have been found, according to statistics, in the intracranial tumors that can cause epilepsy, 10% are oligodendroglioma, in addition to epilepsy, patients still have headaches (80%), mental disorders (50%), limb weakness (45%), etc., the course of the disease is mostly progressive, may suddenly aggravate, mental symptoms are common in patients with frontal oligodendroglioma, especially extensive infiltration, Along the corpus callosum to the contralateral frontal lobe, more manifestations of neurological symptoms, mainly emotional abnormalities and dementia, increased intracranial pressure in about half of the patients, generally appear later, in addition to headache, vomiting, visual acuity and optic disc edema patients Take up 1/3, tumor invasion movement, sensory area can produce hemiplegia, partial sensory disturbance and motor or sensory aphasia, anaplastic oligodendroglioma, most patients with shorter course, high blood pressure symptoms and nervous system The symptoms of the stove are obvious.
Examine
Examination of oligodendroglioma and anaplastic oligodendroglioma
1. The most prominent feature of the skull X-ray plain glioma is calcification. X-ray plain film shows that most of the calcified plaques are banded or patchy, accounting for 34% to 70%. Epithelial tumors can occur. Local skull thinning, signs of increased intracranial pressure are seen in more than 30% of patients.
2. CT scans are mostly low-density occupancy images, 90% of the tumors have high-density calcifications, often in the peripheral part of the tumor, non-calcified parts appear as equal, low-density shadows, and sometimes enhanced after enhancement.
3. MRI scan tumor T1 weighted image showed low signal, T2 weighted image was high signal, peripheral edema was easy to distinguish from tumor, if tumor had large calcification, MRI showed low signal area, oligodendroglioma after injection The contrast enhancement is more prominent.
Diagnosis
Diagnosis and differentiation of oligodendroglioma and anaplastic oligodendroglioma
A definitive diagnosis can be made based on the patient's clinical performance and auxiliary examination.
In imaging, gliomas without obvious calcification need to be differentiated from astrocytoma, and calcified tumors should be differentiated from arteriovenous malformations. The latter often show no peripheral edema and calcification, abnormal blood vessels and Hemosiderin is often coexisting, and abnormal blood vessels can be bifurcated, tubular or dot-like anomalous signals, with low signals in T1-weighted images and proton-density-weighted images, and high signals on T2-weighted even-echo images. In the gradient echo weighted image can be directly displayed, intravenous Gd-DTPA enhanced MRI scan can help identify, anaplastic oligodendroglioma in addition to imaging calcification, peritumoral edema, some patients with high degree of malignancy CT MRI performance is similar to glioblastoma.
