While all tumors are either benign (noncancerous) or malignant (cancerous), they’re also categorized as either primary or secondary, known as metastatic:
Primary brain tumors start in the brain or the tissues near it, like the membranes covering the brain called the meninges or the pituitary gland. These types of tumors happen when mutations occur in the DNA of normal cells, causing the cells to multiply abnormally and survive in conditions normal cells wouldn’t.
Secondary brain tumors come from cancer that starts somewhere else in the body and then spreads or metastasizes to the brain. Sometimes, a secondary brain tumor is the first sign of a cancer that’s started in another location.
Types of tumors:
There are more than 100 different types of brain and intracranial (tumors within the skull that may not be a part of the brain itself) tumors. They get their name from the kind of cell in which they first form (for example, astrocytomas arise from astrocyte cells). Some examples of brain and intracranial tumors found in adults include:
Meningiomas: A meningioma is a tumor that starts in the meninges, the protective coverings of your brain and spinal cord. Most meningiomas are slow-growing and are often benign, meaning they don’t invade nearby tissue or metastasize to other body parts. However, some meningiomas exhibit locally aggressive behavior, invading and weakening nearby bones or other structures. Surgery can cure most meningiomas, although optimal treatment for some includes both surgery and radiation.
Gliomas: These are brain tumors that start in the glial cells, which help keep nerves healthy. There are many categories of gliomas, and they’re the brain tumors that are most likely to be malignant or cancerous. Some examples of gliomas include glioblastomas, astrocytomas, and oligodendrogliomas. Glioblastoma is the most common and aggressive type of primary brain cancer in adults. Doctors frequently treat these tumors with a combination of surgery, radiation, and chemotherapy.
Pituitary Adenomas: Pituitary adenomas are intracranial tumors that grow on the pituitary gland. While they are usually not cancerous, they can cause issues by releasing excess hormones produced by the pituitary gland. Even adenomas that don’t release hormones (nonfunctioning adenomas) can create symptoms by putting pressure on nearby structures, such as the optic nerve or internal carotid arteries. When successfully treated, pituitary tumors often improve and can go away altogether.
Schwannomas: These tumors originate from the Schwann cells that create the protective, insulating sheath surrounding neurons. Schwannomas tend to grow slowly and are generally benign. However, in rare cases, they can be malignant. Many schwannomas can be treated and cured through surgery, while sometimes, radiation therapy after the surgery is recommended.
Brain Tumor Treatment
As with all other facets of a brain tumor, optimal treatment depends on the brain tumor’s type, location, size, growth rate, and your overall health. There is no single treatment that works best—each brain tumor is as unique as the person diagnosed with one. Often, a combination of treatments is used, and personalized approaches, like tumor profiling to look for specific gene mutations, can help determine the best treatments.
Optimal tumor treatment will involve a collaborative approach between neurosurgeons, neuro-oncologists, medical oncologists, radiation oncologists, and other specialists who work together to achieve the best possible outcome.