What Are Brain Tumors?
Ever wondered what actually defines a brain tumor? It’s not just a lump in the brain—it’s a complex condition that can behave in very different ways.
A brain tumor is essentially an abnormal growth of cells in or around your brain. Some grow slowly and stay in one place (benign), while others grow aggressively and invade nearby tissues (malignant). You’ll also hear about primary tumors, which start in the brain, and secondary tumors, which spread from cancers elsewhere in the body.
The symptoms? They vary—from constant headaches and vision problems to changes in memory, personality, or coordination. But one thing’s certain: early detection can make a world of difference.
1. Glioblastoma (GBM): The Most Aggressive Brain Tumor
If there’s one word that captures glioblastoma, it’s relentless.
This tumor is the most aggressive form of brain cancer. It starts in the glial cells—specifically astrocytes—and spreads like wildfire. Most people with GBM experience symptoms like sudden headaches, seizures, or cognitive changes. The worst part? It grows fast and is notoriously hard to remove entirely with surgery.
Treatment usually involves a combination of surgery, radiation, and chemotherapy. But even then, recurrence is common. Still, researchers are pushing boundaries every day to find better ways to fight back.
2. Astrocytoma: From Low-Grade to High-Grade
Astrocytoma comes in many shapes and severities. Think of it as a spectrum.
Low-grade astrocytomas (Grade I or II) often grow slowly and may not even need immediate treatment beyond monitoring. But the higher-grade ones (like anaplastic astrocytoma or Grade III) can turn more aggressive—and eventually become glioblastomas.
What sets astrocytomas apart is their origin in the supportive tissue of the brain. They’re more common in younger adults and can appear almost anywhere in the brain. The treatment? Depends on the grade—but often a mix of surgery, radiation, and chemo.
3. Meningioma: A Common but Often Benign Tumor
Let’s bust a myth—not all brain tumors are cancer. Enter meningioma.
This is one of the most common brain tumors, and thankfully, many are benign. It starts in the meninges—the protective membranes around the brain and spinal cord.
You might not notice it at first. Some people live with small meningiomas without any symptoms. Others experience headaches, vision problems, or even personality changes depending on the tumor’s location.
Treatment is usually surgical, but if the tumor is small and not growing, doctors may just watch and wait.
4. Oligodendroglioma: Slow-Growing but Persistent
With a name like oligodendroglioma, you’d expect something rare—and you’d be right.
These tumors develop from oligodendrocytes, the cells that help insulate nerves. They’re often slow-growing, which sounds like a good thing—until you realise they tend to return after treatment.
The silver lining? They often respond better to chemotherapy and radiation than some other brain tumors. And if the tumor carries a 1p/19q co-deletion, the outlook can be more favourable.
5. Ependymoma: Tumors Near the Brain’s Ventricles
Ependymomas often affect children, but they can occur in adults too.
These tumors grow near the brain’s ventricles—the fluid-filled spaces—and can block the flow of cerebrospinal fluid. This blockage can cause increased pressure inside the skull, leading to headaches, nausea, and vision changes.
Treatment usually starts with surgical removal, followed by radiation. But because they’re near critical structures, complete removal isn’t always possible.
6. Medulloblastoma: A Childhood Brain Cancer
Medulloblastoma is the most common cancerous brain tumor in children.
It forms at the base of the brain, in the cerebellum, which controls coordination and balance. Symptoms include clumsiness, trouble walking, headaches, and vomiting. The tumor can also spread through spinal fluid to other parts of the brain or spine.
Treatment is intense—surgery, radiation, and chemotherapy—but outcomes have improved significantly over the years.
7. Pituitary Tumors: Hormone-Producing Growths
Think your hormones are out of whack? Sometimes, the pituitary gland is the culprit.
Pituitary tumors are usually benign but can wreak havoc by overproducing or blocking hormones. Symptoms might include unexplained weight gain, irregular periods, mood changes, or even vision loss if the tumor presses on the optic nerve.
Most are manageable with medication, but some require surgery—especially if they interfere with vision or hormone control.
8. Metastatic Brain Tumors: When Cancer Spreads to the Brain
What happens when cancer doesn’t start in the brain—but ends up there?
Metastatic brain tumors are actually more common than primary ones. Lung, breast, kidney, and melanoma cancers are the usual suspects.
These tumors can cause seizures, weakness, confusion, and headaches. Treatment focuses on the original cancer while controlling symptoms in the brain through radiation or surgery.
How Are Brain Tumors Diagnosed?
Here’s the million-dollar question: How do doctors even know what type of brain tumor someone has?
It usually starts with an MRI or CT scan to get a good look at the brain. But imaging alone isn’t enough. A biopsy—taking a small piece of the tumor to examine under a microscope—is often necessary to confirm the diagnosis.
More recently, genetic and molecular testing of tumors has become crucial. Knowing the tumor’s genetic makeup can help predict behaviour and guide treatment options.
Treatment Approaches Based on Tumor Type
There’s no one-size-fits-all approach.
- Surgery is often the first step, especially if the tumor is accessible and causing pressure.
- Radiation therapy may follow, targeting leftover cancer cells.
- Chemotherapy works better for certain types, like medulloblastoma or oligodendroglioma.
- Targeted therapy and immunotherapy are the new kids on the block, focusing on the tumor’s specific traits.
Doctors weigh many factors before choosing a treatment: tumor type, location, grade, and the patient’s overall health.
Living with a Brain Tumor: What to Expect
Being diagnosed with a brain tumor changes everything. But it doesn’t mean hope is lost.
Some people live for years—even decades—after diagnosis. Others face more urgent challenges. Either way, support matters. Patients often need:
- Physical or occupational therapy
- Speech therapy
- Anti-seizure medication
- Mental health support
And of course, regular follow-ups to monitor for recurrence or side effects.
References
- “Types of Brain Tumors,” American Brain Tumor Association, 2023. https://www.abta.org/brain-tumor-information/types-of-tumors/
- “Glioblastoma Treatment (GBM),” Mayo Clinic, 2024. https://www.mayoclinic.org/diseases-conditions/glioblastoma/diagnosis-treatment
- “Brain Tumor Diagnosis and Tests,” Johns Hopkins Medicine, 2023. https://www.hopkinsmedicine.org/health/conditions-and-diseases/brain-tumor/brain-tumor-diagnosis-and-tests
- “Brain Tumors in Children,” St. Jude Children’s Research Hospital, 2023. https://www.stjude.org/disease/brain-tumor.html
- “Metastatic Brain Tumors,” Cleveland Clinic, 2024. https://my.clevelandclinic.org/health/diseases/6008-metastatic-brain-tumors