Skull Base Tumors

Understanding Skull Base Tumors & Conditions

Skull base tumors grow near important nerves and structures in the brain. As they get bigger, these tumors can cause a variety of symptoms, depending on their size and location. 

Skull Base Tumor Symptoms

Symptoms of skull base tumors may appear gradually or suddenly, and they vary from person to person. Symptoms may include:

• Visual changes
• Double vision
• Hormonal changes, which can lead to irregular menstruation, fatigue or unexplained changes in weight
• Hearing loss in one ear
• Ringing (tinnitus) in only one ear
• A heartbeat sound in one ear (pulse-synchronous tinnitus)
• New or worsening balance problems or dizziness
• Facial numbness, tingling or weakness on one side of the face
• Nasal drainage of clear fluid
• Nasal congestion
• Headaches or facial pain
• Swallowing impairment and voice changes

Many skull base tumors are benign (non-cancerous) and slow growing. Patients who get an early diagnosis and appropriate treatment often have good long-term outcomes.

Types of Skull Base Tumors

Skull base tumors can develop in different areas at the base of the skull: the front (anterior), middle or back (posterior) part of the skull base. Tumors in the front part often affect vision, hormone levels and sometimes cause changes in the nose function. Tumors in the middle area can impact hearing, balance and sensation in the face. Those in the back part may cause problems with hearing, balance, swallowing, and weakness in the arms or legs.

Some of the most common tumors observed in these regions are:

Anterior fossa skull base tumors

• Paranasal sinus tumors
• Esthesioneuroblastoma (oflactory neuroblastoma)
• Meningiomas

Middle fossa skull base tumors

• Pituitary adenomas
• Craniopharyngioma
• Meningiomas

Posterior fossa skull base tumors

• Acoustic neuroma (vestibular schwannoma)
• Meningiomas
• Chordomas
• Chondrosarcomas
• Epidermoid cysts
• Paraganglioma

In addition to tumors, our skull base experts also manage other complex skull base conditions, including cerebrospinal fluid leaks and microvascular conflicts:

Cerebrospinal Fluid (CSF) leak—Spontaneous

Brain fluid can leak out of the thin bone of the skull base overlying the nose or the ear. The fluid is clear like water. Anterior leaks typically present with clear nasal drainage worse when bending forward. Lateral leaks typically present with muffled hearing with clear fluid in the middle ear.

Having an active CSF leak increase the risk of meningitis or infection of the brain.

Most patients with spontaneous CSF leaks are overweight which contributes to conditions like sleep apnea or elevated intracranial pressure that over time can thin the bone of the skull base resulting in a CSF leak.

Microvascular conflicts

Microvascular conflict occurs when a blood vessel presses against a cranial nerve, causing irritation. This can lead to conditions like trigeminal neuralgia, hemifacial spasms or glossopharyngeal neuralgia. Symptoms often come and go but can worsen over time. Diagnosis is typically made using MRI scans, which help doctors see the close contact between the blood vessel and the affected nerve, confirming the source of the symptoms.

Trigeminal neuralgia

• Causes sudden, intense, electric shock-like facial pain
• Pain usually affects one side of the face, often around the cheek, jaw, or forehead
• Attacks can be triggered by simple actions like chewing, speaking, or touching the face
• Episodes last from seconds to minutes but can repeat frequently

Hemifacial spasms

• Involuntary, repetitive twitching or contractions of muscles on one side of the face
• Usually starts around the eye and may spread to other facial muscles
• Can be persistent and worsen over time, affecting daily activities
• Often caused by irritation of the facial nerve due to blood vessel compression

Skull Base Tumor Diagnosis

If your doctor thinks you might have a skull base tumor, they will do a full evaluation to determine the type, size and location of the tumor. They will also want to learn how the tumor might be affecting your brain in this area of the skull.

An evaluation for skull base tumors typically includes:

• A detailed medical history and physical examination. Your doctor will ask about your past health conditions and evaluate your nervous system, including your brain, spinal cord and nerves. They will also check how the nerves that connect to your brain (cranial nerves) are working.
• Magnetic resonance imaging (MRI). This is the most important imaging tool for visualizing the soft tissues, nerves and structures in your brain.
• Computed tomography (CT). This scan provides detailed images of bone structures. CT images help your doctor plan surgery.
• Hearing tests (audiometry). This helps your doctor check for tumors near the auditory nerve, such as acoustic neuromas, which can affect your hearing.
• Endocrine evaluation and blood tests. These can help confirm a tumor on the pituitary gland at the base of the skull.
• Neuro-ophthalmological evaluation. Specialized evaluation to degree of visual changes in selected cases that have visual symptoms.
• Nasal endoscopy. This imaging uses a camera in a small tube inserted through your nose to look for tumors affecting your nasal cavity. This can also check for CSF leaks.
• Microscopic ear exam. Your doctor will look for middle ear tumors or fluid behind the ear drum.
• Biopsy. If needed, your doctor may remove tissue to view under a microscope to check for tumors.

Treatment

At IU Health, you will be evaluated by doctors specializing in the management of skull base tumors. The subspecialty and team members included in your care will be selected according to the very specific needs of your case.

The treatment of a skull base tumor is personalized for each patient. Factors that influence treatment include the type of tumor you have, the size and location of the tumor, your overall health and the severity of your symptoms.

Skull base tumor treatment options can include:

Observation or "Watchful Waiting”

If your tumor is small or it isn’t causing any symptoms, your doctor may want to monitor the tumor over time. This observation is sometimes called “watchful waiting.” During observation, you would have repeat imaging and exams.

Surgery

Your doctor may recommend surgery to remove your skull base tumor. Surgeons have several advanced options to remove or reduce tumors while maximizing function preservation and quality of life and minimizing complications. Surgical options include:

• Endoscopic endonasal surgery. This surgery uses a thin tube and a camera inserted through the nose to treat some selected skull base tumors and CSF leaks. Common tumors treated via endoscopic approach include pituitary adenomas, craniopharyngiomas and chordomas.
• Microsurgery uses specialized instruments to remove tumors through the skull. This approach can treat a large variety of tumor, including acoustic neuromas and meningiomas.
• Minimally invasive techniques whenever possible, to speed recovery and reduce complications.

Radiation therapy

Stereotactic radiosurgery uses focused beams of radiation to treat tumors. This non-invasive option includes Gamma Knife or similar radiation technologies. Radiation therapy is a good option to treat certain skull base tumors or prevent them from getting bigger.

Medications

Some selected tumors can be managed with medications. This includes functional pituitary adenomas. Hormone replacement therapy may also be needed after skull base tumor surgery.

Cerebrospinal fluid (CSF) leak repair

Spontaneous CSF leaks from the nose are typically treated by repairing the anterior skull base using instruments and a small endoscope camera passed through your nose without external incisions. .

If you have a lateral skull base CSF leak from the ear, your doctor will perform a small craniotomy above the ear to repair the skull base from inside the head using using microsurgery.

Microvascular conflict

Medications are typically tried as first-line treatment for trigeminal neuralgia or hemifacial spasm. Surgery or radiation treatments are chosen if conservative measures are ineffective. Surgery involves repositioning the blood vessel pressing on the nerve that leads to the symptoms.

Specialized skull base care

Improvements in microsurgery, endoscopy and radiosurgery have significantly improved quality of life for patients with skull base tumors. These options reduce complications and help patients maintain neurological function. While more aggressive tumors may require intensive treatments and closer follow-up, the multidisciplinary care teams at IU Health are equipped to provide the latest therapies and personalized care plans to help you achieve the best possible outcome.

The right care for you

When you receive care at IU Health, you benefit from comprehensive treatment at an academic health center. This includes:

• Access to a team of nationally recognized specialists
• Leading-edge technology and surgical tools
• Participation in clinical trials and ongoing research
• Patient-centered care and long-term follow-up

If you are experiencing symptoms or have been diagnosed with a skull base tumor, IU Health specialists are here to help.