FRIDAY, Jan. 23, 2026 — Brain tumors are abnormal growths of cells in or around the brain. They can be primary (originating in the brain) or secondary (metastatic, spreading to the brain from cancer elsewhere).
They can also originate from the structures around the brain, like the dura (brain lining), the nerves or the bone of the skull. Not all brain tumors are cancerous.
Benign tumors typically grow more slowly and may not invade nearby tissue the way malignant tumors do, but even benign tumors can cause serious problems by pressing on key nerves, arteries or the brain itself. Understanding types, symptoms, diagnosis and treatment helps patients and families navigate care.
Types of brain tumors
Benign tumors can be effectively treated or controlled and generally have fewer complications, but they can still cause serious problems if incompletely treated.
Malignant tumors grow more aggressively, infiltrate surrounding brain or skull tissue, and can sometimes spread within the central nervous system. Metastatic tumors originate outside the brain or skull and spread to these areas.
Noncancerous (benign) brain tumors
Meningiomas
Arising from the meninges (membranes covering the brain and spinal cord), meningiomas are the most common primary brain tumors in adults. Many are slow-growing and are incidentally discovered.
Symptoms result from pressure on nearby brain or nerve tissue and may include headaches, vision changes, seizures or problems like double vision, numbness or weakness, depending on location. A rare subset of meningiomas is atypical or anaplastic (higher grade) and behaves more aggressively.
Pituitary adenomas
These develop in the pituitary gland at the base of the brain. Some secrete hormones (such as prolactin, growth hormone or adrenocorticotropic hormone), causing endocrine symptoms such as menstrual changes, milk production, excess levels of growth hormone or Cushing’s disease.
Excess growth hormone (acromegaly) and Cushing’s disease can shorten life. Non-functioning adenomas can cause visual symptoms by compressing the optic nerves or loss of hormone function by compressing the normal pituitary gland.
Treatment involves medications for prolactin-secreting types or minimally invasive surgery through the nose (endoscopic endonasal surgery).
Vestibular schwannomas (acoustic neuromas)
These are tumors of nerve sheath cells in the vestibular (balance) nerve. They typically cause one-sided hearing loss, tinnitus (ringing in the ear), imbalance and sometimes facial numbness or weakness if large.
Depending on size and symptoms, management ranges from observation with periodic MRIs to focused radiation (Gamma Knife stereotactic radiosurgery) or microsurgical removal.
Craniopharyngiomas
These are other benign, often cyst-forming tumors near the pituitary gland, its stalk, or a crucial brain region called the hypothalamus, which regulates everything from sleep to hunger to thirst.
Theoretically derived from normal tissue leftover from development, these tumors can cause hormone deficiencies, growth issues, excessive thirst/urination, and visual disturbances. Even after treatment, they often recur and may require a combination of surgery, radiation, targeted drug therapies and long-term endocrine care.
Hemangioblastomas
Hemangioblastomas are tumors that form balls of loose blood vessels and often occur in the cerebellum and spinal cord. They can be sporadic or associated with von Hippel–Lindau syndrome, which can be hereditary.
Symptoms include headaches, coordination problems and water on the brain (hydrocephalus) if they obstruct cerebrospinal fluid flow. Surgical removal is typical for larger tumors and Gamma Knife is very effective for others; targeted treatments are evolving for inherited, genetic cases.
Pineal region tumors (benign)
Tumors arising from the pineal gland can often be benign and are typically slow-growing. They can cause headaches, visual disturbances, and hydrocephalus by blocking cerebrospinal fluid pathways.
Management may include surgery and, in select cases, radiation. Pineal region cysts are very rarely symptomatic and are usually only monitored and not treated.
Choroid plexus papillomas
These tumors arise from the tissue that produces cerebrospinal fluid (CSF). More common in children, these can overproduce CSF and cause hydrocephalus. Treatment usually involves surgical removal; outcomes are generally good. Smaller tumors respond well to Gamma Knife radiosurgery.
Cancerous (malignant) brain tumors
Low-grade gliomas (e.g., astrocytomas, oligodendrogliomas)
These are slow-growing primary brain tumors that form from glial cells. They often present with seizures in young adults and can cause subtle cognitive or neurological changes.
Molecular features influence prognosis and guide therapy. Even though they grow more slowly, they infiltrate brain tissue and can become higher-grade tumors over time. The lowest grade tumors can be cured with surgery or well-controlled with radiation.
High-grade gliomas (e.g., glioblastoma)
These rapidly growing, infiltrative tumors are the most common malignant primary brain tumors in adults. Symptoms evolve quickly and may include headaches, seizures and deficits like numbness, weakness or trouble with speech.
Treatment typically combines removing as much of the tumor as possible, followed by radiation therapy and chemotherapy (for example, temozolomide), and may involve a type of cancer therapy called tumor treating fields or clinical trials. For recurrent tumors, many approaches are explored, including repeat surgery, radiosurgery and drug therapies.
Ependymomas
These arise from cells lining the brain’s ventricles (sacks in the brain that produce and circulate cerebrospinal fluid) or the spinal canal. They occur in children and adults. They can block the flow of cerebrospinal fluid, leading to hydrocephalus and headaches.
Treatment involves surgical removal, often followed by radiation; chemotherapy is used in selected cases. Up to date classification also incorporates genetics that affect prognosis.
Medulloblastomas
These fast-growing tumors of the cerebellum are more common in children and can spread through cerebrospinal fluid to other parts of the brain and spinal cord. Symptoms include headaches, nausea and problems with balance and coordination.
Treatment typically involves surgery, craniospinal radiation (depending on patient age) and chemotherapy. Care is tailored to the tumor’s molecular subtype and the patient’s risk.
Primary central nervous system lymphoma
This is a type of non-Hodgkin lymphoma confined to the brain, spinal cord and eyes. It is more common in people with compromised immunity suppression but can occur in others as well.
Diagnosis often uses MRI and biopsy; treatment is based on high-dose methotrexate-containing chemotherapy regimens, with or without radiation.
Pineal region malignant tumors (e.g., germinomas)
These can cause hydrocephalus, vision changes and endocrine symptoms. Germinomas are typically managed through biopsy and a combination of chemotherapy and radiation, guided by precise pathology and staging.
Choroid plexus carcinoma
A rare malignant tumor that occurs more often in children, these can cause significant hydrocephalus and increased pressure inside the skull. Treatment includes aggressive surgical removal when possible, followed by chemotherapy and, in some cases, radiation.
Metastatic brain tumors
The most common of all brain malignancies, these originate from cancers elsewhere in the body — commonly lung, breast, melanoma, kidney and colorectal — that spread to the brain via the bloodstream.
They may be solitary or multiple and often present with headaches, seizures or deficits like numbness, weakness of speech problems. Treatment options include surgery, stereotactic radiosurgery, whole-brain radiation and systemic therapies tailored to the primary cancer as well as corticosteroids for symptom control.
Over the last 10 to 15 years, great improvements in outcomes have been achieved for many patients.
Chordoma/Chondrosarcoma
Chordomas and chondrosarcomas are rare tumors that can grow from the base of the skull and spine.
They have a wide variety of aggressiveness, but chordomas are generally considered to be cancerous because they are very difficult to cure, even when they are slow-growing. The best outcomes are achieved with complete removal, usually followed by high-dose radiation.
Sinonasal Cancers
Some cancers that come from the sinuses can invade the brain or skull tissue under the brain. These are managed in concert with ear, nose and throat surgeons, often combining chemo- and radiation therapy with surgery.
Important caveats
Some “usually benign” tumors can have atypical or anaplastic forms that behave more aggressively, necessitating closer monitoring or additional (adjuvant) therapy.
Even benign tumors can be serious, because they occupy space within the skull and may compress critical brain structures.
Modern classifications include molecular and genetic markers that refine diagnosis and inform prognosis and treatment across many tumor types. Discussing the specific pathology and molecular features of a tumor with the care team is essential.
Symptoms of brain tumors
Brain areas control specific functions, so symptoms depend on tumor location, size and growth rate. Common symptoms include:
Headaches: These are often worse in the morning or with straining, new or changing patterns, and are sometimes accompanied by nausea or vomiting due to increased pressure in the skull. These can be worrisome if they are severe enough to wake someone up at night.
Headaches: These are often worse in the morning or with straining, new or changing patterns, and are sometimes accompanied by nausea or vomiting due to increased pressure in the skull. These can be worrisome if they are severe enough to wake someone up at night.
Seizures: New-onset seizures in adults are a common presenting sign. Seizures can be generalized (loss of consciousness, convulsions) or focal (jerking or sensations in one body part, or sudden cessation of speech).
Seizures: New-onset seizures in adults are a common presenting sign. Seizures can be generalized (loss of consciousness, convulsions) or focal (jerking or sensations in one body part, or sudden cessation of speech).
Focal neurological deficits: These may include weakness or numbness on one side, difficulty with coordination or problems walking, if the cerebellum is affected.
Focal neurological deficits: These may include weakness or numbness on one side, difficulty with coordination or problems walking, if the cerebellum is affected.
Vision and eye problems: Among these are blurred or double vision, visual field loss (e.g., losing peripheral vision) and new difficulty seeing colors or reading. Pituitary tumors, meningiomas and craniopharyngiomas may all cause progressive vision decline.
Vision and eye problems: Among these are blurred or double vision, visual field loss (e.g., losing peripheral vision) and new difficulty seeing colors or reading. Pituitary tumors, meningiomas and craniopharyngiomas may all cause progressive vision decline.
Speech and language changes: People may have trouble finding words, slurred speech, difficulty understanding or producing language if dominant hemisphere areas are involved.
Speech and language changes: People may have trouble finding words, slurred speech, difficulty understanding or producing language if dominant hemisphere areas are involved.
Cognitive and personality changes: These symptoms may include memory loss, confusion, slowed thinking, apathy, irritability, or changes in judgment and behavior — particularly with frontal lobe tumors, which can often get large before they are recognized.
Cognitive and personality changes: These symptoms may include memory loss, confusion, slowed thinking, apathy, irritability, or changes in judgment and behavior — particularly with frontal lobe tumors, which can often get large before they are recognized.
Hearing loss and tinnitus: These typically affect only one side, with balance issues in vestibular schwannomas.
Hearing loss and tinnitus: These typically affect only one side, with balance issues in vestibular schwannomas.
Nausea and vomiting: Symptoms may occur especially with increased intracranial pressure or hydrocephalus.
Nausea and vomiting: Symptoms may occur especially with increased intracranial pressure or hydrocephalus.
Endocrine symptoms: Among these are irregular periods, milk secretion (galactorrhea), weight changes, heat/cold intolerance, excessive thirst and urination from pituitary-related tumors.
Endocrine symptoms: Among these are irregular periods, milk secretion (galactorrhea), weight changes, heat/cold intolerance, excessive thirst and urination from pituitary-related tumors.
Fatigue and sleep disturbances: These are non-specific but common.
Fatigue and sleep disturbances: These are non-specific but common.
How brain tumors are diagnosed
Diagnosis typically begins with a primary care physician or an emergency visit if symptoms are severe.
A patient may then be referred to a neurosurgeon or neurologist for a detailed neurological exam, and to specialists such as a neuro-oncologist (medical cancer specialist for brain tumors), a neurosurgeon (surgical management), and a radiation oncologist.
If hormone issues are suspected, an endocrinologist may be involved, and a neuro-ophthalmologist may be needed to evaluate vision problems. Referral to a multidisciplinary brain tumor center can usually provide all of these in one location.
Key steps:
Medical history and neurological examination: This includes testing nerves, strength, sensation, reflexes, coordination, vision and mental status.
Medical history and neurological examination: This includes testing nerves, strength, sensation, reflexes, coordination, vision and mental status.
Imaging: An MRI of the brain with and without contrast is the gold standard. Specialized sequences (perfusion, diffusion, spectroscopy) and functional MRI may be used. CT scans help in emergencies or to assess calcifications and bone involvement. For suspected metastases, imaging of the body (CT chest/abdomen/pelvis, PET) may be performed to find the primary cancer.
Imaging: An MRI of the brain with and without contrast is the gold standard. Specialized sequences (perfusion, diffusion, spectroscopy) and functional MRI may be used. CT scans help in emergencies or to assess calcifications and bone involvement. For suspected metastases, imaging of the body (CT chest/abdomen/pelvis, PET) may be performed to find the primary cancer.
Laboratory tests: Among these are hormone panels for pituitary tumors; basic bloodwork to assess overall health; and sometimes, viral or immune status for lymphoma.
Laboratory tests: Among these are hormone panels for pituitary tumors; basic bloodwork to assess overall health; and sometimes, viral or immune status for lymphoma.
Lumbar puncture (spinal tap): In select cases, this may be ordered to analyze cerebrospinal fluid for cancer cells or markers, especially in germinoma, lymphoma or medulloblastoma. The may be avoided when raised pressure in the head is suspected unless deemed safe.
Lumbar puncture (spinal tap): In select cases, this may be ordered to analyze cerebrospinal fluid for cancer cells or markers, especially in germinoma, lymphoma or medulloblastoma. The may be avoided when raised pressure in the head is suspected unless deemed safe.
Biopsy or surgical resection: Tissue diagnosis is often necessary. This may be via a stereotactic needle biopsy guided by imaging or removal of part/all of the tumor via craniotomy or endoscopic endonasal approach for pituitary tumors. Pathologists classify the tumor under WHO (World Health Organization) criteria and assess molecular markers, which guide prognosis and treatment.
Biopsy or surgical resection: Tissue diagnosis is often necessary. This may be via a stereotactic needle biopsy guided by imaging or removal of part/all of the tumor via craniotomy or endoscopic endonasal approach for pituitary tumors. Pathologists classify the tumor under WHO (World Health Organization) criteria and assess molecular markers, which guide prognosis and treatment.
How brain tumors are treated
Treatment is individualized based on tumor type, size, location, molecular features and patient health.
Watchful waiting (active surveillance): Small, non-cancerous tumors not causing symptoms may be monitored with periodic MRIs and exams.
Watchful waiting (active surveillance): Small, non-cancerous tumors not causing symptoms may be monitored with periodic MRIs and exams.
Corticosteroids: Medications like dexamethasone reduce brain swelling and improve symptoms short-term.
Corticosteroids: Medications like dexamethasone reduce brain swelling and improve symptoms short-term.
Anti-seizure medications: These are used to prevent or control seizures in patients who have had them.
Anti-seizure medications: These are used to prevent or control seizures in patients who have had them.
Surgery: The aim is to remove as much tumor as safely possible. Techniques include craniotomy (opening the skull); awake mapping to preserve speech or movement; and endoscopic endonasal surgery for many tumors at the base of the skull (meningiomas, craniopharyngioma, chordomas) or pituitary adenomas. Complete removal may be possible for some benign tumors.Malignant tumors that have invaded into nearby tissue sometimes require partial removal.
Surgery: The aim is to remove as much tumor as safely possible. Techniques include craniotomy (opening the skull); awake mapping to preserve speech or movement; and endoscopic endonasal surgery for many tumors at the base of the skull (meningiomas, craniopharyngioma, chordomas) or pituitary adenomas. Complete removal may be possible for some benign tumors.Malignant tumors that have invaded into nearby tissue sometimes require partial removal.
Radiosurgery or radiotherapy: External beam radiation (including IMRT) targets residual tumor cells. Stereotactic radiosurgery (Gamma Knife, CyberKnife) delivers precise, high-dose radiation to small tumors or metastases. Proton therapy may spare surrounding tissue in certain cases. Radiation use is common after surgery for high-grade gliomas, chordomas and for many metastases and benign tumors that cannot be safely removed.
Radiosurgery or radiotherapy: External beam radiation (including IMRT) targets residual tumor cells. Stereotactic radiosurgery (Gamma Knife, CyberKnife) delivers precise, high-dose radiation to small tumors or metastases. Proton therapy may spare surrounding tissue in certain cases. Radiation use is common after surgery for high-grade gliomas, chordomas and for many metastases and benign tumors that cannot be safely removed.
Chemotherapy: Drugs like temozolomide are standard for glioblastoma; PCV (procarbazine, lomustine, vincristine) for oligodendroglioma; high-dose methotrexate-based regimens for CNS lymphoma; various pediatric protocols for medulloblastoma and ependymoma. Side effects and schedules vary.
Chemotherapy: Drugs like temozolomide are standard for glioblastoma; PCV (procarbazine, lomustine, vincristine) for oligodendroglioma; high-dose methotrexate-based regimens for CNS lymphoma; various pediatric protocols for medulloblastoma and ependymoma. Side effects and schedules vary.
Targeted and biologic therapies: Bevacizumab (anti-VEGF) can reduce swelling and symptoms in recurrent glioblastoma. Some tumors respond to BRAF or MEK inhibitors when specific mutations are present. Tumor treating fields, which are wearable devices delivering low-intensity electrical fields, can be used in glioblastoma. Tumors can be tested for specific defects to see what targeted therapies can be used.
Targeted and biologic therapies: Bevacizumab (anti-VEGF) can reduce swelling and symptoms in recurrent glioblastoma. Some tumors respond to BRAF or MEK inhibitors when specific mutations are present. Tumor treating fields, which are wearable devices delivering low-intensity electrical fields, can be used in glioblastoma. Tumors can be tested for specific defects to see what targeted therapies can be used.
Clinical trials: These offer access to investigational therapies and combinations that may improve outcomes. Many times these are free of charge as part of a study.
Clinical trials: These offer access to investigational therapies and combinations that may improve outcomes. Many times these are free of charge as part of a study.
Supportive procedures: These include ventriculoperitoneal shunt or endoscopic third ventriculostomy to relieve hydrocephalus; rehabilitation therapies (physical, occupational, speech) to improve function; and endocrine therapy for pituitary-related hormone imbalances.
Supportive procedures: These include ventriculoperitoneal shunt or endoscopic third ventriculostomy to relieve hydrocephalus; rehabilitation therapies (physical, occupational, speech) to improve function; and endocrine therapy for pituitary-related hormone imbalances.
What causes brain tumors?
For most brain tumors, the exact cause is unknown. They result from genetic changes that alter cell growth and survival, and are sometimes influenced by inherited syndromes or environmental exposures. Unlike many other cancers, brain tumors are rarely linked to lifestyle factors (such as diet or alcohol use).
Metastatic brain tumors are caused by cancer cells spreading through the bloodstream or cerebrospinal fluid from a primary tumor elsewhere.
Brain tumor risk factors
Age: Some tumors (medulloblastoma, ependymoma) are more common in children; others (glioblastoma, meningioma) occur more often in older adults.
Age: Some tumors (medulloblastoma, ependymoma) are more common in children; others (glioblastoma, meningioma) occur more often in older adults.
Sex: Meningiomas are more common in women; glioblastoma is slightly more common in men.
Sex: Meningiomas are more common in women; glioblastoma is slightly more common in men.
Ionizing radiation: Prior therapeutic radiation to the head increases risk years later.
Ionizing radiation: Prior therapeutic radiation to the head increases risk years later.
Family history/genetic syndromes: Neurofibromatosis type 1 and 2 (schwannomas, meningiomas, gliomas); Li-Fraumeni (various tumors); von Hippel–Lindau (hemangioblastomas); tuberous sclerosis (subependymal giant cell astrocytomas); Cowden/PTEN hamartoma syndrome (meningiomas); Lynch/Turcot (medulloblastoma, gliomas).
Family history/genetic syndromes: Neurofibromatosis type 1 and 2 (schwannomas, meningiomas, gliomas); Li-Fraumeni (various tumors); von Hippel–Lindau (hemangioblastomas); tuberous sclerosis (subependymal giant cell astrocytomas); Cowden/PTEN hamartoma syndrome (meningiomas); Lynch/Turcot (medulloblastoma, gliomas).
Immune suppression: HIV/AIDS, organ transplantation or immunosuppressive medications increase risk of CNS lymphoma.
Immune suppression: HIV/AIDS, organ transplantation or immunosuppressive medications increase risk of CNS lymphoma.
Certain occupational exposures: High-dose solvents or chemicals have been studied, but evidence is mixed and often inconclusive.
Certain occupational exposures: High-dose solvents or chemicals have been studied, but evidence is mixed and often inconclusive.
Previous cancers: People with aggressive cancers (lung, melanoma, breast, kidney) have higher risk of brain metastases.
Previous cancers: People with aggressive cancers (lung, melanoma, breast, kidney) have higher risk of brain metastases.
Obesity and hormones: Obesity is linked to higher risk of meningioma; prolonged hormones from pills or implants (progesterone) may influence some meningiomas.
Obesity and hormones: Obesity is linked to higher risk of meningioma; prolonged hormones from pills or implants (progesterone) may influence some meningiomas.
Radiation from everyday devices: Typical cell phone use has not been conclusively linked; large studies remain ongoing and generally reassuring.
Radiation from everyday devices: Typical cell phone use has not been conclusively linked; large studies remain ongoing and generally reassuring.
Living with a brain tumor: Complications and long-term considerations
Living with a brain tumor can involve navigating both the effects of the tumor and side effects of treatment. Possible complications include:
Neurological deficits: These may include persistent weakness, sensory changes, speech or language problems, vision or hearing loss, and coordination difficulties, depending on tumor location and treatment.
Neurological deficits: These may include persistent weakness, sensory changes, speech or language problems, vision or hearing loss, and coordination difficulties, depending on tumor location and treatment.
Seizure disorder: Even after treatment, some patients continue to have seizures and must take anti-epileptic medications and follow safety precautions.
Seizure disorder: Even after treatment, some patients continue to have seizures and must take anti-epileptic medications and follow safety precautions.
Cognitive and emotional changes: Memory problems, slowed processing, attention difficulties, depression, anxiety and personality changes may occur. Neuropsychological evaluation and cognitive rehabilitation may help.
Cognitive and emotional changes: Memory problems, slowed processing, attention difficulties, depression, anxiety and personality changes may occur. Neuropsychological evaluation and cognitive rehabilitation may help.
Hydrocephalus and intracranial pressure: Some patients need long-term shunt management or monitoring for fluid buildup.
Hydrocephalus and intracranial pressure: Some patients need long-term shunt management or monitoring for fluid buildup.
Endocrine issues: Pituitary and hypothalamic tumors or their treatments can cause chronic hormone deficiencies, requiring replacement therapy.
Endocrine issues: Pituitary and hypothalamic tumors or their treatments can cause chronic hormone deficiencies, requiring replacement therapy.
Treatment side effects: Radiation can cause fatigue, skin changes, hair loss and late effects like tissue damage or cognitive decline. Chemotherapy may cause nausea, low blood counts, increased infection risk and neuropathy. Steroids can lead to weight gain, mood changes, high blood sugar and bone loss.
Treatment side effects: Radiation can cause fatigue, skin changes, hair loss and late effects like tissue damage or cognitive decline. Chemotherapy may cause nausea, low blood counts, increased infection risk and neuropathy. Steroids can lead to weight gain, mood changes, high blood sugar and bone loss.
Functional impacts: These may include driving restrictions after seizures, challenges with work or school, and the need for assistive devices or home modifications.
Functional impacts: These may include driving restrictions after seizures, challenges with work or school, and the need for assistive devices or home modifications.
Recurrence and surveillance: Many tumors require long-term MRI monitoring. Recurrence may necessitate additional surgery, radiation or systemic therapy.
Recurrence and surveillance: Many tumors require long-term MRI monitoring. Recurrence may necessitate additional surgery, radiation or systemic therapy.
Thromboembolism: Certain tumors and treatments increase risk of blood clots, requiring vigilance for swelling or chest symptoms.
Thromboembolism: Certain tumors and treatments increase risk of blood clots, requiring vigilance for swelling or chest symptoms.
Fertility and family planning: Treatments can affect fertility; consultation with reproductive specialists before therapy may be helpful.
Fertility and family planning: Treatments can affect fertility; consultation with reproductive specialists before therapy may be helpful.
Palliative and supportive care: Symptom management, advance care planning,and psychosocial support improve quality of life. Social workers, rehabilitation therapists, support groups and counseling can be invaluable.
Palliative and supportive care: Symptom management, advance care planning,and psychosocial support improve quality of life. Social workers, rehabilitation therapists, support groups and counseling can be invaluable.
If you or a loved one is experiencing new neurological symptoms, prompt evaluation is essential.
Early diagnosis and a coordinated care team — including neurosurgery, neuro-oncology, radiation oncology, neurology, endocrinology and rehabilitation — provide the best chance for effective treatment and symptom control.
About the experts
Paul A. Gardner, MD, is vice chair of clinical innovation for the Department of Neurosurgery at NYU Grossman School of Medicine and director of the NYU Langone Skull Base Surgery Center.
Douglas Kondziolka, MD, is vice chair of clinical research for the Department of Neurosurgery at NYU Grossman School of Medicine and director of the NYU Langone Center for Advanced Radiosurgery and the Gamma Knife Program.
