Brain Tumor

What is a brain tumor?

A brain tumor is a collection, or mass, of abnormal cells in your brain. Your skull, which encloses your brain, is very rigid. Any growth inside such a restricted space can cause problems. Brain tumors can be cancerous (malignant) or noncancerous (benign). When benign or malignant tumors grow, they can cause the pressure inside your skull to increase. This can cause brain damage, and it can be life-threatening.

Brain tumors are categorized as primary or secondary. A primary brain tumor originates in your brain. Many primary brain tumors are benign. A secondary brain tumor, also known as a metastatic brain tumor, occurs when cancer cells spread to your brain from another organ, such as your lung or breast.

Types of brain tumors

Primary brain tumors

Primary brain tumors originate in your brain. They can develop from your:

brain cells

the membranes that surround your brain, which are called meninges

nerve cells

glands

Primary tumors can be benign or cancerous. In adults, the most common types of brain tumors are gliomas and meningiomas.

Gliomas

Gliomas are tumors that develop from glial cells. These cells normally:

support the structure of your central nervous system

provide nutrition to your central nervous system

clean cellular waste

break down dead neurons

Gliomas can develop from different types of glial cells.

The types of tumors that begin in glial cells are:

astrocytic tumors such as astrocytomas, which originate in the cerebrum

oligodendroglial tumors, which are often found in the frontal temporal lobes

glioblastomas, which originate in the supportive brain tissue and are the most aggressive type

Other primary brain tumors

Other primary brain tumors include:

pituitary tumors, which are usually benign

pineal gland tumors, which can be benign or malignant

ependymomas, which are usually benign

craniopharyngiomas, which occur mostly in children and are benign but can have clinical symptoms like changes in vision and premature puberty

primary central nervous system (CNS) lymphomas, which are malignant

primary germ cell tumors of the brain, which can be benign or malignant

meningiomas, which originate in the meninges

schwannomas, which originate in cells that produce the protective cover of your nerves (myelin sheath) called Schwann cells

Most meningiomas and schwannomas occur in people between the ages of 40 and 70. Meningiomas are more common in women than men. Schwannomas occur equally in both men and women. These tumors are usually benign, but they can cause complications because of their size and location. Cancerous meningiomas and schwannomas are rare but can be very aggressive.

Secondary brain tumors

Secondary brain tumors make up the majority of brain cancers. They start in one part of the body and spread, or metastasize, to the brain. The following can metastasize to the brain:

lung cancer

breast cancer

kidney cancer

skin cancer

Secondary brain tumors are always malignant. Benign tumors don’t spread from one part of your body to another.

What are the symptoms of a brain tumor?

Symptoms of brain tumors depend on the location and size of the tumor. Some tumors cause direct damage by invading brain tissue and some tumors cause pressure on the surrounding brain. You’ll have noticeable symptoms when a growing tumor is putting pressure on your brain tissue.

Headaches are a common symptom of a brain tumor. You may experience headaches that:

are worse in the morning when waking up

occur while you’re sleeping

are made worse by coughing, sneezing, or exercise

You may also experience:

vomiting

blurred vision or double vision

confusion

seizures (especially in adults)

weakness of a limb or part of the face

a change in mental functioning

Other common symptoms include:

clumsiness

memory loss

confusion

difficulty writing or reading

changes in the ability to hear, taste, or smell

decreased alertness, which may include drowsiness and loss of consciousness

difficulty swallowing

dizziness or vertigo

eye problems, such as drooping eyelids and unequal pupils

uncontrollable movements

hand tremors

loss of balance

loss of bladder or bowel control

numbness or tingling on one side of the body

trouble speaking or understanding what others are saying

changes in mood, personality, emotions, and behavior

difficulty walking

muscle weakness in the face, arm, or leg

Symptoms of pituitary tumors

The following symptoms can occur with pituitary tumors:

nipple discharge, or galactorrhea

lack of menstruation in women

development of breast tissue in men, or gynecomastia

enlargement of the hands and feet

sensitivity to heat or cold

increased amounts of body hair, or hirsutism

low blood pressure

obesity

changes in vision, such as blurry vision or tunnel vision

How are brain tumors diagnosed?

Diagnosis of a brain tumor begins with a physical exam and a look at your medical history.

The physical exam includes a very detailed neurological examination. Your doctor will conduct a test to see if your cranial nerves are intact. These are the nerves that originate in your brain.

Your doctor will look inside your eyes with an ophthalmoscope, which is an instrument that shines a light through your pupils and onto your retinas. This allows your doctor to check how your pupils react to light. It also allows your doctor to look directly into your eyes to see if there’s any swelling of the optic nerve. When pressure increases inside the skull, changes in the optic nerve can occur.

The doctor may also evaluate your:

muscle strength

coordination

memory

ability to do mathematical calculations

Your doctor may order more tests after they finish the physical exam. These could include:

CT scan of the head

CT scans are ways for your doctor get a more detailed scan of your body than they could with an X-ray machine. This can be done with or without contrast.

Contrast is achieved in a CT scan of the head by using a special dye that helps doctors see some structures, like blood vessels, more clearly.

MRI of the head

If you have an MRI of your head, a special dye can be used to help your doctor detect tumors. An MRI is different from a CT scan because it doesn’t use radiation, and it generally provides much more detailed pictures of the structures of the brain itself.

Angiography

This study uses a dye that’s injected into your artery, usually in the groin area. The dye travels to the arteries in your brain. It allows your doctor to see what the blood supply of the tumors looks like. This information is useful at the time of surgery.

Skull X-rays

Brain tumors can cause breaks or fractures in the bones of the skull, and specific X-rays can show if this has occurred. These X-rays can also pick up calcium deposits, which are sometimes contained within a tumor. Calcium deposits may be in your bloodstream if your cancer has moved to your bones.

Biopsy

A small piece of the tumor is obtained during a biopsy. A specialist called a neuropathologist will examine it. The biopsy will identify if the tumor cells are benign or malignant. It will also determine whether the cancer originated in your brain or another part of your body.