Brain Tumor – Symptoms and Causes
Overview
Brain tumors are abnormal cell growths that occur in or near the brain. They can develop in brain tissue or nearby areas, including nerves, the pituitary gland, the pineal gland, or the protective membranes around the brain.
These growths vary widely in size. Some are found early due to noticeable symptoms, while others can grow large without being detected, especially in less active brain areas.
When tumors begin in the brain, they are called primary brain tumors. Those that spread to the brain from elsewhere in the body are called secondary, or metastatic, brain tumors.
Treatment approaches typically include surgery and radiation therapy, with specific plans based on the tumor’s type, size, and location.
Types of Brain Tumors
Brain tumors are classified by their cell origin, using lab tests to identify their specific type. Some brain tumors are noncancerous (benign), while others are cancerous (malignant).
Benign tumors typically grow slowly, while malignant ones tend to grow rapidly.
Common brain tumor types include:
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Gliomas – These develop from glial cells that support nerve cells. Types include:
- Astrocytoma
- Glioblastoma (most common malignant brain tumor)
- Oligodendroglioma
- Ependymoma
Meningiomas – The most common benign brain tumors, originating in the membranes surrounding the brain and spinal cord.
Nerve Tumors – These grow in and around nerves, with acoustic neuroma (schwannoma) being the most common type in the head.
Pituitary Tumors – Usually benign growths that develop in or near the pituitary gland at the base of the brain.
Choroid Plexus Tumors – Located in the brain’s fluid-filled ventricles, these tumors start in cells that produce cerebrospinal fluid. They can be benign or malignant (choroid plexus carcinoma).
Embryonal Tumors – Malignant tumors that form from leftover fetal cells, most common in young children. Medulloblastoma is the most frequent type, typically found in the cerebellum.
Germ Cell Tumors – Usually benign tumors that begin in reproductive cells and can develop near the pineal or pituitary glands. These are more common in children.
Pineal Tumors – Develop in or around the pineal gland in the brain’s center. These can be benign or malignant, with pineoblastoma being a malignant form most common in children.
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Other less common brain tumors include:
- Tumors originating from skull bones
- Growths developing in muscles, blood vessels, or connective tissue
- Primary central nervous system lymphoma (cancer starting in immune cells in the brain)
The specific type of brain tumor plays a crucial role in determining treatment approaches and prognosis. Brain tumors can significantly impact normal brain function by pressing on brain tissue or invading and destroying healthy cells.
Brain Tumor Warning Signs
Headache Patterns
Brain tumor headaches often feel worse in the morning when you wake up. The pain may even wake you from your sleep. These headaches typically get worse when you cough or strain.
Many people describe them as feeling like tension headaches, while others compare them to migraines.
If the tumor is in the back of your head, you might feel pain in both your head and neck. Tumors in the front part can cause pain that feels like it’s coming from your eyes or sinuses.
About half of all people with brain tumors experience headaches. Pain occurs when a tumor pushes against healthy brain tissue or causes swelling, increasing pressure in the skull.
Location-Based Symptoms
Brain tumors cause different symptoms depending on where they grow:
Front of the brain (frontal lobes):
- Balance problems
- Difficulty walking
- Personality changes
- Memory issues
- Loss of interest in normal activities
- Behavior that family members notice as “different”
Middle of the brain (parietal lobes):
- Problems with senses
- Vision difficulties
- Hearing issues
- Trouble processing touch, taste, or smell
Back of the brain (occipital lobes):
- Vision loss
- Visual disturbances
Sides of the brain (temporal lobes):
- Memory problems
- Experiencing sensations that aren’t real
- Unusual tastes or smells
- Unpleasant sensory experiences
When to Call Your Doctor
Make an appointment with your healthcare provider if you notice any of these symptoms that don’t go away:
- Headaches that are getting worse or more frequent
- Nausea or vomiting without clear cause
- Blurry vision, double vision, or vision loss
- Weakness or numbness in an arm or leg
- Balance problems
- Speech difficulties
- Unusual tiredness
- Confusion with everyday tasks
- Memory problems
- Trouble following simple instructions
- Changes in personality or behavior
- Seizures, especially if you’ve never had them before
- Hearing problems
- Dizziness or vertigo
- Increased hunger and weight gain
Non-cancerous brain tumors typically develop slowly, with subtle symptoms that worsen over months or years. Cancerous tumors tend to cause symptoms that appear suddenly and worsen within days or weeks.
What Causes Brain Tumors
Tumors That Start in the Brain
Primary brain tumors begin as abnormal cell growth directly in the brain or nearby tissues. These tumors can develop in several places:
- The brain tissue itself
- Protective membranes (meninges) covering the brain
- Nerves near the brain
- The pituitary and pineal glands
The root cause of primary brain tumors is DNA changes in brain cells. DNA holds the essential blueprints for guiding cellular behavior.
Then these instructions change, cells may grow too quickly and live longer than they should. This creates extra cells that form a tumor.
For most people with brain tumors, doctors cannot identify what caused these DNA changes. Some people inherit DNA changes from their parents, which increases their risk of developing brain tumors.
These hereditary cases are indeed quite uncommon. Children more commonly develop primary brain tumors, while adults often have secondary tumors from cancer that started elsewhere.
Cancer That Spreads to the Brain
Secondary brain tumors occur when cancer begins in another part of the body and spreads to the brain. This is called metastatic cancer.
Several types of cancer commonly spread to the brain:
- Breast Cancer
- Lung Cancer
- Melanoma (Skin Cancer)
- Kidney Cancer
- Colon Cancer
Scientists don’t fully understand why some cancers travel to the brain while others spread to different parts of the body.
Most people who develop secondary brain tumors already know they have cancer elsewhere. In rare cases, a brain tumor might be the first sign that cancer exists in the body.
Secondary brain tumors are much more common than primary brain tumors in adults.
Risk Factors
Multiple factors may raise the risk of developing a brain tumor, but the exact cause of most primary brain tumors is still unknown.
Age
While these tumors can occur at any age, they appear more frequently in older adults. Certain types of brain tumors tend to affect specific age groupsโsome primarily affecting adults, others more commonly seen in children.
Racial Differences
White people experience higher rates of gliomas, while Black people develop meningiomas more frequently. However, brain tumors can affect people of all races.
Radiation Exposure
Exposure to high-energy ionizing radiation increases brain tumor risk. This type of radiation can damage DNA in cells, potentially leading to tumor growth. Sources include:
- Cancer radiation treatments
- Atomic bomb exposure
Low-level radiation from everyday sources like cell phones and radio waves has not been convincingly linked to brain tumors. Research continues in this area to confirm these findings.
Inherited Genetic Conditions
| Genetic Syndrome | Key Features |
|---|---|
| Neurofibromatosis (types 1 & 2) | Nerve tissue tumors |
| Tuberous sclerosis | Benign tumors in multiple organs |
| Lynch syndrome | Increased cancer risk |
| Li-Fraumeni syndrome | Early-onset cancers |
| Von Hippel-Lindau disease | Blood vessel tumors |
| Familial adenomatous polyposis | Colonic polyps and tumors |
| Cowden syndrome | Multiple hamartomas |
| Gorlin syndrome | Basal cell carcinomas |
These genetic conditions involve DNA changes that run in families and can increase susceptibility to brain tumors.
Prevention
It is impossible to prevent brain tumors. A brain tumor is not caused by anything you did or didn’t do.
For those with higher-risk factors, screening tests may be helpful. Screening doesn’t prevent tumors, but it can find them when they’re smaller and more treatable.
Talk to your healthcare provider if brain tumors are common in your family or if you have genetic syndromes that increase your risk.
Meet with a genetic counselor and discuss your personal risk factors.
Screening may involve advanced brain imaging tests. It might also include neurological exams that check vision, hearing, balance, coordination, and reflexes.
