What is a brain tumor?
脑瘤是大脑中异常细胞的生长. The anatomy of the brain is very complex, with different parts responsible for different nervous system functions. 脑瘤可以发生在大脑或颅骨的任何部位, including its protective lining, the underside of the brain (skull base)、脑干、鼻窦和鼻腔以及许多其他部位. There are more than 120 different types of tumors that can develop in the brain, depending on what tissue they arise from.
脑瘤有多常见?它们危险吗?
In the United States, brain and nervous system tumors affect about 30 adults out of 100,000. Brain tumors are dangerous because they can put pressure on healthy parts of the brain or spread into those areas. 一些脑瘤也可能癌变或变成癌变. 如果它们阻碍了大脑周围的液体流动，就会引起问题, 这会导致颅骨内压力增加吗. Some types of tumors can spread through the spinal fluid to distant areas of the brain or the spine.
How is a tumor different from a brain lesion?
脑肿瘤是一种特殊类型的脑部病变. A lesion describes any area of damaged tissue. 所有肿瘤都是病变，但并非所有病变都是肿瘤. Other brain lesions can be caused by stroke, injury, encephalitis and arteriovenous malformation.
Brain Tumor vs. Brain Cancer
所有的脑癌都是肿瘤，但不是所有的脑瘤都是癌变的. 非癌性脑瘤称为良性脑瘤.
Benign brain tumors typically grow slowly, have distinct borders and rarely spread. Benign tumors can still be dangerous. 它们会损伤和压迫大脑的某些部分，导致严重的功能障碍. Benign brain tumors located in a vital area of the brain can be life-threatening. Very rarely, a benign tumor can become malignant. Examples of typically benign tumors include meningioma, vestibular schwannoma and pituitary adenoma.
Malignant brain tumors are cancerous. 它们通常生长迅速，并侵入周围健康的大脑结构. Brain cancer can be life-threatening due to the changes it causes to the vital structures of the brain. 一些起源于大脑或大脑附近的恶性肿瘤包括 olfactory neuroblastoma, chondrosarcoma and medulloblastoma.
Primary vs. Metastatic Brain Tumors
原发性脑瘤是起源于大脑的肿瘤. Examples of tumors that most often originate in the brain include meningioma and glioma. Very rarely, these tumors can break away and spread to other parts of the brain and spinal cord. 更常见的是，肿瘤从身体的其他部位扩散到大脑.
Metastatic brain tumors, also called secondary brain tumors, are malignant tumors that originate as cancer elsewhere in the body and then metastasize (spread) to the brain. Metastatic brain tumors are about four times more common than primary brain tumors. 它们可以迅速生长，挤占或侵入附近的脑组织.
Common cancers that can spread to the brain are:
Brain Tumor Locations
Brain tumors can form in any part of the brain，但在某些区域会形成特定的肿瘤:
- Meningiomas 形成于脑膜，大脑的保护层.
- Pituitary tumors develop in the pituitary gland.
- Medulloblastoma tumors arise from the cerebellum or brainstem.
- Skull base tumors 长在大脑的下方，叫做颅底.
其他脑肿瘤是由它们构成的细胞种类来描述的. 例如，胶质瘤是由神经胶质细胞组成的.
Brain Tumors in Children
脑瘤是儿童和青少年中最常见的实体瘤, affecting about 5,000 children in the U.S. each year. Several different types of brain tumors can occur in children, including astrocytomas (e.g.如多形性胶质母细胞瘤、胶质瘤、室管膜瘤和髓母细胞瘤.
Learn more about brain tumors in children.
Brain Tumor Symptoms
大脑的不同部分控制着不同的功能, 所以脑肿瘤的症状会因肿瘤的位置而异. For example, a brain tumor located in the cerebellum at the back of the head may cause trouble with movement, walking, balance and coordination. If the tumor affects the optic pathway, which is responsible for sight, vision changes may occur.
The tumor’s size and how fast it’s growing also affect which symptoms a person will experience.
一般来说，脑肿瘤最常见的症状可能包括:
Can you have a brain tumor with no symptoms?
Brain tumors don’t always cause symptoms. In fact, the most common brain tumor in adults, meningioma, often grows so slowly that it goes unnoticed. Tumors may not start causing symptoms until they become large enough to interfere with healthy tissues inside the brain.
Brain Tumor Causes and Risk Factors
医生不知道为什么有些细胞开始形成肿瘤细胞. It may have something to do with a person’s genes or his or her environment, or both. 脑瘤的潜在病因和危险因素包括:
- Cancers that spread from other parts of the body
- Certain genetic conditions that predispose a person to overproduction of certain cells
- Exposure to some forms of radiation
Are brain tumors hereditary?
基因是导致少数脑瘤(少于5%)的原因. Some inherited conditions put individuals at greater risk of developing tumors, including:
- Neurofibromatosis
- Von Hippel-Lindau disease
- Li-Fraumeni syndrome
- Familial adenomatous polyposis
- Lynch syndrome
- Basal cell nevus syndrome (Gorlin syndrome)
- Tuberous sclerosis
- Cowden syndrome
Brain Tumor Diagnosis
诊断脑肿瘤通常需要进行神经学检查, brain scans and a biopsy, if it can be done safely.
- A neurological exam may include a variety of tests to evaluate neurological functions such as balance, hearing, vision and reflexes.
- A variety of imaging techniques, including CT (or CAT) scan, MRI, 偶尔可以用血管造影或x光来识别肿瘤, 精确定位它的位置和/或评估你的大脑功能.
- If doctors cannot safely perform a biopsy (tissue sample collection and analysis), they will diagnose the brain tumor and plan the treatment based on other test results. If a biopsy was possible, 医生可以用它来确定肿瘤的等级(肿瘤的侵袭性), as well as study the tumor tissue for any biomarkers that can help personalize the treatment approach.
Depending on your symptoms, doctors may also perform these tests to help confirm the diagnosis and rule out other conditions:
- Lumbar puncture to collect a sample of cerebrospinal fluid and see if it contains traces of the tumor cells.
- Evoked potentials studies 测量神经和/或 electroencephalography (EEG) to measure electrical activity in the brain.
- 神经认知评估，以评估认知和幸福感的任何变化.
- Neuro-ophthalmological examination to assess for signs of tumor affecting the eyes.
- 内分泌学评价评估激素功能.
正确的诊断对于确定最佳治疗方案至关重要.
Brain Tumor Grading
脑肿瘤的级别决定了它的严重程度. Using the biopsy sample, a pathologist will examine the tumor under a microscope to determine its grade. Brain tumor grading is a category system that describes the brain tumor cells and indicates how likely the tumor is to grow and spread.
Brain tumor grading uses a scale from 1 (least aggressive) to 4 (most aggressive).
(World Health Organization tumor grading system)
Grade I brain tumor
- Benign (noncancerous)
- Slow-growing
- Cells look almost normal under a microscope
- Usually associated with long-term survival
- Rare in adults
Grade II brain tumor
- Relatively slow-growing
- 有时扩散到附近的正常组织并复发。
- Cells look slightly abnormal under a microscope
- Sometimes comes back as a higher grade tumor
Grade III brain tumor
- Malignant (cancerous)
- Actively reproduces abnormal cells
- 肿瘤扩散到大脑附近的正常部位
- Cells look abnormal under a microscope
- 易复发，常为更高级别肿瘤
Grade IV brain tumor
- Malignant
- Most aggressive
- Grows fast
- 很容易扩散到大脑附近的正常部位
- Actively reproduces abnormal cells
- Cells look very abnormal under a microscope
- 肿瘤形成新的血管以保持快速生长
- 肿瘤中心有死细胞区域(称为坏死)。
A changing diagnosis
The grade of a brain tumor might change, usually to a higher grade, often without a cause. It’s also possible that the biopsy sample might not represent the entire tumor, giving an inaccurate initial data for the grade.
A change from a low-grade tumor to a high-grade tumor happens more often in adults than in children.
Brain Tumor Staging
Staging refers to how far a tumor has spread. 如果肿瘤已经转移到身体的其他部位，它就已经转移了. 分期通常用于其他类型的肿瘤，但是 not primary brain tumors. This is because brain tumors are unlikely to spread beyond the nervous system.
Conversely, other types of tumors (e.g., lung cancer) can spread to the brain. 已经扩散到脑部的肿瘤是晚期.
What does the size of a brain tumor mean?
因为较大的肿瘤更容易干扰正常的大脑功能, 它们通常会引起症状和并发症.
Brain Tumor Treatment
脑肿瘤最常见的治疗方法是手术. For some tumors, surgical removal and continued monitoring may be the only treatment needed. 常见的脑肿瘤切除手术包括 craniotomy, neuroendoscopy, laser ablation and laser interstitial thermal therapy.
Chemotherapy and radiation therapy can be used to treat brain cancer by helping shrink the tumor, 减缓它的生长和/或防止它复发. External beam radiation therapy, stereotactic radiosurgery and proton therapy 有一些放射治疗是针对脑瘤的吗.
The Johns Hopkins Brain Tumor Center
The Johns Hopkins Comprehensive Brain Tumor Center is one of the largest brain tumor treatment and research centers in the world. 我们使用一系列先进的方法为每位患者量身定制治疗方案, including emerging treatments such as tumor-treating fields and MRI-guided laser ablation.
Brain Tumor Prognosis
Brain tumor can be a frightening diagnosis. It’s important to partner with a medical team you trust to determine the best next steps, whether it’s observation, surgery, radiation therapy or another treatment. How successful your personal outcome will be depends on many factors, including:
- 脑肿瘤的类型，大小，分级和位置
- 肿瘤是否已经扩散到大脑内部或身体的其他部位
- Your age and overall health
- 在你被诊断出患有脑瘤之前你有症状多久了
- 脑瘤对你的功能影响有多大
- Your treatment preferences
- The expertise of your treatment team
对于那些被诊断患有脑肿瘤的人来说，没有预测的生存率, as individual circumstances play a big role. For example, some malignant tumors can be successfully controlled by radiation therapy. Others, because of their location, may be life-threatening even if they are benign. Doctors have to look at thousands of patients with similar characteristics to see a trend in how certain tumors progress and how different treatments affect them.
Your overall outlook and prognosis are likely to change as you undergo various treatments. If you have surgery, how much of the tumor the neurosurgeon can remove will impact what will happen next. 其他脑肿瘤治疗也将决定未来的步骤.
