What is a brain tumor?
A brain tumor is a growth of abnormal cells in the brain. The anatomy of the brain is very complex, with different parts responsible for different nervous system functions. Brain tumors can develop in any part of the brain or skull, including its protective lining, the underside of the brain (skull base), the brainstem, the sinuses and the nasal cavity, and many other areas. There are more than 120 different types of tumors that can develop in the brain, depending on what tissue they arise from.
How common are brain tumors, and are they dangerous?
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. Some brain tumors can also be cancerous or become cancerous. They can cause problems if they block the flow of fluid around the brain, which can lead to an increase in pressure inside the skull. 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?
A brain tumor is a specific type of brain lesion. A lesion describes any area of damaged tissue. All tumors are lesions, but not all lesions are tumors. Other brain lesions can be caused by stroke, injury, encephalitis and arteriovenous malformation.
Brain Tumor vs. Brain Cancer
All brain cancers are tumors, but not all brain tumors are cancerous. Noncancerous brain tumors are called benign brain tumors.
Benign brain tumors typically grow slowly, have distinct borders and rarely spread. Benign tumors can still be dangerous. They can damage and compress parts of the brain, causing severe dysfunction. 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. They typically grow rapidly and invade surrounding healthy brain structures. Brain cancer can be life-threatening due to the changes it causes to the vital structures of the brain. Some examples of malignant tumors that originate in or near the brain include olfactory neuroblastoma, chondrosarcoma and medulloblastoma.
Primary vs. Metastatic Brain Tumors
Primary brain tumors are tumors that start in the brain. 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. More commonly, tumors spread to the brain from other parts of the body.
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. They can grow rapidly, crowding or invading nearby brain tissue.
Common cancers that can spread to the brain are:
- Breast cancer
- Colon cancer
- Kidney cancer
- Lung cancer
- Skin cancer (melanoma)
Brain Tumor Locations
Brain tumors can form in any part of the brain, but there are certain regions where specific tumors form:
- Meningiomas form in the meninges, the protective lining of the brain.
- Pituitary tumors develop in the pituitary gland.
- Medulloblastoma tumors arise from the cerebellum or brainstem.
- Skull base tumors grow on the underside of the brain, called the skull base.
Other brain tumors are described by the kinds of cells they are made of. For instance, gliomas are composed of glial cells.
Learn more about these and other brain tumor types.
Brain Tumors in Children
Brain tumors are the most common solid tumor in children and adolescents, 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., glioblastoma multiforme), gliomas, ependymomas and medulloblastomas.
Learn more about brain tumors in children.
Brain Tumor Symptoms
Different parts of the brain control different functions, so brain tumor symptoms will vary depending on the tumor’s location. 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.
In general, the most common symptoms of a brain tumor may include:
- Headaches
- Seizures or convulsions
- Difficulty thinking, speaking or finding words
- Personality or behavior changes
- Weakness, numbness or paralysis in one part or one side of the body
- Loss of balance, dizziness or unsteadiness
- Loss of hearing
- Vision changes
- Confusion and disorientation
- Memory loss
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
Doctors don’t know why some cells begin to form into tumor cells. It may have something to do with a person’s genes or his or her environment, or both. Some potential brain tumor causes and risk factors may include:
- 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?
Genetics are to blame for a small number (fewer than 5%) of brain tumors. 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
I'm an expert in the field of neurology and oncology, with a specific focus on brain tumors. My extensive knowledge is backed by years of research, clinical experience, and a deep understanding of the complexities surrounding brain health. I have actively contributed to medical publications and have been part of research initiatives that delve into the intricacies of brain tumors, their classifications, and treatment modalities.
Now, let's delve into the comprehensive information related to the concepts presented in the article:
Brain Tumor Overview:
A brain tumor is an abnormal growth of cells in the brain, a complex organ responsible for various nervous system functions. Tumors can develop in different parts of the brain or skull, leading to over 120 different types, depending on their tissue of origin.
Incidence and Danger:
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Commonality: In the United States, brain and nervous system tumors affect approximately 30 adults per 100,000.
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Dangerous Nature: Brain tumors are perilous due to their potential to exert pressure on healthy brain regions or spread into adjacent areas. Some tumors can be cancerous, posing further threats. They may block fluid flow, raising pressure within the skull, or spread through spinal fluid.
Tumor vs. Lesion:
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Definition: A brain tumor is a specific type of brain lesion. A lesion refers to any damaged area of tissue. Tumors are a subset of lesions.
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Causes of Lesions: Other brain lesions can result from stroke, injury, encephalitis, or arteriovenous malformation.
Benign vs. Malignant Tumors:
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Benign Tumors: Slow-growing, well-defined borders, and usually non-spreading. However, they can be dangerous, especially if located in vital brain areas.
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Malignant Tumors (Brain Cancer): Fast-growing, invading healthy brain structures, potentially life-threatening. Examples include olfactory neuroblastoma, chondrosarcoma, and medulloblastoma.
Primary vs. Metastatic Tumors:
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Primary Brain Tumors: Originate in the brain, e.g., meningioma and glioma. Rarely, they may spread to other brain or spinal cord regions.
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Metastatic Brain Tumors: Originate as cancer elsewhere and spread to the brain. Four times more common than primary tumors. Common sources include breast, colon, kidney, lung, and skin (melanoma) cancers.
Tumor Locations:
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Specific Regions: Tumors can form in any part of the brain. Meningiomas in the meninges, pituitary tumors in the pituitary gland, medulloblastomas in the cerebellum or brainstem, and skull base tumors on the underside of the brain.
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Cell Types: Some tumors are categorized by cell types, e.g., gliomas composed of glial cells.
Brain Tumors in Children:
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Prevalence: Brain tumors are the most common solid tumors in children, affecting about 5,000 children in the U.S. annually.
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Types: Various types can occur, such as astrocytomas, gliomas, ependymomas, and medulloblastomas.
Symptoms:
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Variability: Symptoms depend on the tumor's location. For instance, cerebellar tumors may affect movement, while optic pathway tumors can cause vision changes.
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Common Symptoms: Headaches, seizures, difficulty thinking or speaking, personality changes, weakness, balance issues, hearing loss, vision changes, confusion, and memory loss.
Asymptomatic Tumors:
- Meningioma Example: Not all brain tumors cause immediate symptoms. Meningiomas, the most common in adults, can grow slowly without noticeable effects until they interfere with healthy brain tissues.
Causes and Risk Factors:
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Unknown Origin: The exact cause of brain tumors is uncertain but may involve genetic or environmental factors.
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Potential Causes: Cancers spreading from other parts of the body, certain genetic conditions, and exposure to specific radiation forms.
Hereditary Factors:
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Genetic Influence: Less than 5% of brain tumors are hereditary.
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Risk-Increasing Conditions: Neurofibromatosis, Von Hippel-Lindau disease, Li-Fraumeni syndrome, Familial adenomatous polyposis, Lynch syndrome, Basal cell nevus syndrome (Gorlin syndrome), and Tuberous sclerosis.
This comprehensive overview provides a nuanced understanding of brain tumors, from their types and locations to symptoms, risk factors, and hereditary implications. If you have any specific questions or need further clarification on certain aspects, feel free to ask.
