intracranial cavernous hemangioma
Introduction
Introduction to intracranial cavernous hemangioma Cavernous hemangioma refers to a spongy abnormal vascular mass composed of a number of thin-walled blood vessels. These deformed blood vessels are closely attached, and there is no or very little brain parenchyma between the blood vessels. They are not true tumors and are classified as cerebrovascular malformations by histological classification. basic knowledge The proportion of sickness: 0.00256% Susceptible people: no special people Mode of infection: non-infectious Complications: hydrocephalus swelling, cerebrospinal fluid leakage
Cause
The cause of intracranial cavernous hemangioma
(1) Causes of the disease
It is not clear so far that there are the following doctrines:
1. Congenital theory that infant patients and family history support the hypothesis of congenital sources. Studies have shown that familial and/or multiple cavernous hemangiomas are more common in Hispanics and are autosomal dominant, suggesting that all Hispanic patients with this disease With the same gene mutation, its mutated gene is located in q11, q22 of the long arm of chromosome 7q.
2. Acquired theory that conventional radiotherapy, viral infection, trauma, surgery, vascular reaction after hemorrhage can induce cavernous hemangioma, Zabramski and other 6 families in 21 cases, 17 new cavernous hemangioma lesions were found after 2.2 years of follow-up Each patient has 0.4 new lesions per year. If the new cavernous hemangioma is more common than expected, the risk of bleeding will be greatly underestimated by the number of congenital cases. The diameter of cavernous hemangioma is from a few millimeters to several The size of the lesion may be caused by repeated small amount of bleeding and embolism in the lesion. Due to the low flow and low pressure of the lesion, the bleeding is often confined within the capsule. Once the bleeding breaks through the wall, it causes obvious symptoms.
(two) pathogenesis
The essence of cavernous hemangioma is the malformed vascular mass. The blood supply artery and drainage vein of the vascular mass are normal diameter vessels. The blood flow rate in the tumor is slow, so cerebral angiography can not show the deformity of the vascular group, and the blood retention is also in the abnormal blood vessel. The cause of thrombosis and calcification, the appearance of the lesion is purple-red, the surface is mulberry-like, the profile is spongy or honeycomb, and the blood vessel wall is composed of a single layer of endothelial cells, lacking muscle layer and elastic layer, and the lumen is filled with blood. There are fresh or old thrombus; the abnormal blood vessels are loose fibrous connective tissue, and there is no or minimal brain parenchymal tissue between the blood vessels.
The texture of the tumor can be soft or hard, which is related to the blood content, the degree of calcification and the size of the thrombus in the deformed vascular mass. There is gliosis and yellow methemoglobin deposition in the brain tissue around the lesion. This methemoglobin is the brain. Cortical cavernous hemangioma causes one of the causes of epilepsy in patients.
Cavernous hemangioma can occur in any part of the central nervous system, such as the cerebral cortex, basal ganglia and brainstem (intracerebral lesions), as well as the middle cranial fossa, retina and cranial bones (extra-cerebral lesions), about 19 % of cases are multiple lesions. Patients with multiple cavernous hemangioma often have hemangiomas with other organs in the body. The size of the tumor varies from 0.5 to 6 cm. The location and size of the tumor are directly related to clinical manifestations.
Domestic reports of lesions often located in the epidural cranial fossa, accounting for 70% to 80%, a small part in the brain, foreign reports of brain lesions are the most common, intracranial lesions often have spontaneous recurrent small amount of bleeding, tumor There are hemosiderin deposition and calcification points, and extra-cerebral lesions are often dominated by space-occupying effects.
Prevention
Intracranial cavernous hemangioma prevention
Strengthen physical exercise, enhance physical fitness, and exercise more in the sun.
Complication
Intracranial cavernous hemangioma complications Complications, hydrocephalus, swelling, cerebrospinal fluid leakage
Postoperative intracranial pressure may increase and hydrocephalus, hemorrhage, brain swelling, etc., such as brain tissue embedded in the dural space of the suture or because the dural meningeal suture is not tight, can cause cerebrospinal fluid leakage, the lesion may be located after the posterior fossa surgery Damage facial nerve.
Symptom
Intracranial cavernous hemangioma symptoms common symptoms nutritional disorders repeated bleeding calcification
Asymptomatic
Accounted for 11% to 44% of the total, mild headache may be the only complaint, often or medical examination to find the disease, whether the headache is related to the bleeding of the lesion needs further research, but 40% of them in 6 months ~ 2 The following symptoms occurred during the year.
2. Epilepsy
40% to 100%, found in most supratentorial cavernous hemangioma, manifested in various forms of epilepsy, cavernous hemangioma is more prone to epilepsy than other lesions occurring in the same site, may be due to cavernous blood vessels The mechanical effects of the tumor on the adjacent brain tissue (ischemia, oppression) and secondary to the leakage of blood and other nutrient disorders, the brain tissue surrounding the lesion often due to hemosiderin deposition, gliosis or calcification becomes an epileptogenic focus, animal experiments confirmed, Cortical or subcortical injection of iron ions can be used to make epilepsy animal models, of which about 40% are refractory epilepsy.
3. Bleeding
From autopsy, surgical specimens or imaging examinations, there are often different stages of bleeding in the lesion, while symptomatic dominant bleeding accounts for 8% to 37%. According to calculations, the patient's annual bleeding rate is 0.25% to 3.1%; The rate is 0.7% to 2%. The deep hemorrhage of the cerebral hemisphere is more likely to bleed. Unlike AVM hemorrhage, hemorrhage of cavernous hemangioma usually occurs in the brain tissue around the lesion, less into the subarachnoid space or ventricle, spongy The prognosis of hemangiomas is better than AVM, but the possibility of re-bleeding after first hemorrhage increases. Female patients, especially pregnant women with cavernous hemangioma, have a higher bleeding rate. Repeated hemorrhage can cause lesions to increase and aggravate local nerve function. Missing.
4. Local neurological deficit
Accounted for 15.4% to 46.6%, acute and progressive local neurological deficits often secondary to lesion hemorrhage, symptoms depending on the location and volume of the lesion, can be expressed as static, progressive or mixed, massive bleeding caused by severe acute neurological symptoms Aggravation is less common.
Examine
Examination of intracranial cavernous hemangioma
No special performance.
1. Skull X-ray film
Mainly manifested in bone destruction near the occupying position, no bone hyperplasia, may have bone absorption in the middle cranial fossa, enlargement of the sella, bone bone bone absorption and internal auditory canal enlargement, etc., may also have high intracranial pressure signs, 8% to 10% of lesions have calcification points, which are common in brain lesions.
2. CT scan
The sensitivity of diagnosis of cavernous hemangioma is 70% to 100%, but the specificity is less than 50%. The image shows a sign of space-filled blood vessels. The extra-brain lesions have a circular or elliptical density with clear boundaries. Or high-density shadow, after the contrast agent is injected, the lesion is slightly enhanced, there is no edema around, such as bleeding in the lesion, high-density images can be seen, and lesions in the brain show uneven and high-density areas with clear boundaries, often with calcified plaques. Mild or no enhancement after injection of contrast agent, CT bone window image can show bone destruction around the lesion.
3.MRI scan
MRI is a specific method for the diagnosis of cavernous hemangioma. The coincidence rate with pathology is 80%-100%. On MRI T1 and T2-weighted images, cavernous hemangioma is the core of the reticular mixed signal in the center (hemorrhage in different periods) And its products), surrounded by a low signal ring (hemosiderin deposition), no enhancement or slight enhancement after injection of contrast agent, newly bleeding, brain tissue around the lesion may have edema.
4. Cerebral angiography
It is characterized by uncharacterized vascular lesions. In the arterial phase, blood supply arteries and pathological blood vessels are rarely seen. In the venous phase or sinus phase, the lesions are partially stained. Cavernous hemangioma is a blood vessel-rich lesion in cerebral angiography. The reason for the lack of development may be that the blood supply artery is too thin or has an embolism. The blood vessels in the lesion are too large, and the blood flow is slow to make the contrast agent diluted. Therefore, the dense vein pool and local lesion staining in the late venous phase are the two of the disease. Great feature.
5. Positron emission scanning (PET)
PET uses brain tissue to absorb radionuclides for brain scan imaging. Head CT or MRI can provide intracranial anatomical images, while PET provides metabolic information to identify brain tumors and cavernous hemangioma. The degree of absorption of radioisotopes is high, while the absorption of cavernous hemangioma is very low.
Diagnosis
Diagnosis and diagnosis of intracranial cavernous hemangioma
diagnosis
Before the onset of CT, the diagnosis of this disease is difficult. The initial diagnosis of this disease is X-ray film, but only calcification can be found and can not be characterized. Most cavernous hemangioma angiography is not developed unless the lesion is large. Obvious occupancy signs or complicated venous malformations. With the development of imaging techniques, the appearance of CT and MRI has greatly improved the diagnostic rate of cavernous hemangioma.
Differential diagnosis
Cavernous hemangioma is mainly distinguished from meningiomas and arteriovenous malformations (AVM). In imaging: round lesions in the brain, with mixed density (representing varying degrees of bleeding), MRI T2 images with methemoglobin deposition It is a feature of cavernous hemangioma.
