At the MedStar Georgetown University Hospital Skull Base Center, we are committed to achieving the best outcomes for patients suffering from conditions of the brain, skull, and spinal cord. Our center features skilled physicians trained in the latest neurosurgical techniques and offers a unique combination of state-of-the-art tools and expertise that makes us one of the most comprehensive centers in the entire country.
The term “skull base” refers to the gap between the bottom of the brain and the part of the skull directly below it. Within the skull base are all the blood vessels that supply the brain with nutrients and oxygen, as well as nerves that are critical to functions such as vision, smell, hearing, facial movement and breathing.
Types of Skull Base Conditions
- Acoustic neuroma
- Cerebrospinal fluid (CSF) leak and encephalocele
- Chordomas in the clivus and upper cervical spine
- Glomus tumors
- Glossopharyngeal neuralgia
- Infratemporal fossa and pterygopalatine fossa tumors
- Jugular foramen tumors
- Nasopharyngeal tumors (benign and malignant)
- Orbital and optic nerve tumors/optic nerve compression
- Petrous apex lesions
- Pineal tumors
- Pituitary tumors, including craniopharyngioma and pituitary adenomas
- Sinonasal tumors, benign and malignant
- Trigeminal neuralgia
- Trigeminal schwannomas
An acoustic neuroma is a benign (noncancerous) brain tumor that grows on the vestibular cochlear nerve, which influences balance and hearing. The vestibular cochlear nerve runs from your brain to your inner ear. Acoustic neuromas are rare and usually slow growing.
What causes them is unclear, although in some cases, they’re thought to be genetic. Symptoms can include:
- Hearing loss
- Ringing in your ear (tinnitus)
As they grow, acoustic neuromas can press against key brain structures, threatening your ability to hear, even how you move your face. If left untreated, some acoustic neuromas may grow large enough to cause permanent hearing loss and can be life-threatening. Others are small enough that they don’t cause any problems and won’t need any treatment besides regular observation by your physician.
Cerebrospinal fluid (CSF) is a clear liquid that surrounds the brain and spinal cord. CSF helps to protect the brain and spinal cord from injury, regulate internal pressure, circulate nutrients and chemicals, and clear away the body’s waste products. In a healthy body, CSF is enclosed in a membrane called the dura, which is entirely contained by the skull and spinal column.
A type of abnormality called an encephalocele occurs when the dura and CSF bulge out of an opening in the skull. The thin bone of the middle part of the ear and roof of the nose and sinuses are particularly susceptible to these defects. An encephalocele looks like a round growth inside the nose or ear and can be visualized with MRI and CT scans. This condition is treated surgically.
CSF can also seep out of the dura and into the sinus cavity, without creating a visible growth. This is called a CSF leak. Sometimes, CSF leaks have no clear cause. Other times, they are caused by injury or elevated pressure inside the head. Leaks must be repaired to protect the brain and to prevent complications, such as meningitis.
Symptoms of a CSF leak may include:
- Headaches that get worse when sitting up
- Neck pain
- Liquid draining from the nose or ears
- Changes in hearing
A chordoma is a rare type of tumor. Sometimes, these tumors occur on a bone in skull base called the clivus. Others occur on the upper cervical spine (the neck).
Chordomas are caused by cells associated with a structure called the notochord. The notochord is involved in fetal development of the spine and nerve system. Typically, notochord cells disappear from the body before birth, but they sometimes remain in the body through adulthood. When this happens, notochord cells can sometimes grow out of control, forming a chordoma.
Chordomas are most common in adults age 40-60. There are often no noticeable symptoms. However, some patients experience symptoms such as:
- Changes in mobility
Chordomas in the clivus and upper cervical spine often create problems by crowding other structures in the body, including the brain and spinal cord. These growths are frequently treated with a combination of both skull base surgery and radiation.
A glioma is a type of brain tumor that arises from glial cells, brain cells that act like “glue” within the central nervous system by holding neurons into place and protecting them. Gliomas are known for their invasive nature; they tend to grow and spread into normal brain tissue. This often complicates treatment options.
Nearly 80 percent of all cancerous brain tumors are gliomas, although not all gliomas are cancerous. Symptoms may include:
- Memory Loss
- Physical weakness or loss of muscle control
Treatment approaches depend upon the tumor’s location, cell type, grade of malignancy (the rate at which the tumor grows and spreads) and the patient’s personal health and circumstances.
The infratemporal fossa and pterygopalatine fossa are complex spaces behind the sinuses and just below the skull base. They are often difficult to access because of all of the surrounding structures that encase them. Tumors can develop within these spaces. These tumors may be benign (non-cancerous) or malignant (cancerous). Benign tumors, such as schwannomas and juvenile nasopharyngeal angiofibromas (JNA), will not spread to other parts of the body, but may crowd other structures in the skull base and create other problems. Cancerous tumors such as squamous cell carcinoma or adenoid cystic carcinoma present a risk of spreading to other parts of the body.
Symptoms of infratemporal fossa and pterygopalatine fossa tumors may include:
- Facial pain or swelling
- Facial or palate numbness
- Pain or a full feeling in the ears
- Lockjaw or difficulty chewing
Because these tumors are in hard-to-access parts of the skull, they can be difficult to detect and require advanced techniques to remove.
A meningioma is a tumor that grows in the membranes that surround your brain and spinal cord, known as the meninges. A meningioma can be either benign (noncancerous) or malignant (cancerous).
When these tumors occur in the skull base, near structures called the cavernous sinus, petrous bone, clivus or posterior fossa, they can encircle blood vessels and nerves. Although meningiomas don’t always occur in the skull base, when they do, they can be very difficult to remove. Therefore, it is important to find a physician who specializes in skull base surgery to treat them.
Symptoms of a meningioma aren’t always readily apparent and usually come on gradually. They can include:
- Eye blurriness or double vision
- Weakness in your arm or leg
- Hearing loss
- Loss of your sense of smell
Meningiomas require an exceptional level of skill to resect (surgically remove) because they are often difficult to access and located near delicate structures within the brain or spinal cord.
The nasopharynx is a term for the upper part of the throat, behind the nose. Sometimes, cells in the nasopharynx can begin to grow out of control. This causes a nasopharyngeal tumor to develop.
Symptoms of nasopharyngeal tumors may include:
- Hearing loss
- Nose bleeds
- Nasal blockage
- Vision problems
A nasopharyngeal tumor can be benign (non-cancerous) or malignant (cancerous). Benign tumors are rare, but found most commonly children and young adults. Although these benign tumors will not spread to other parts of the body, they can grow in size and present health complications. Therefore, they usually need to be surgically removed. Removal of benign nasopharyngeal tumors can often be completed endoscopically.
Cancerous nasopharyngeal tumors can indicate one of several types of cancer, including nasopharyngeal carcinoma (NPC), lymphoma, adenocarcinoma, and adenoid cystic carcinoma. Treatments may vary depending on the type of cancer that is found.
Orbital and optic nerve tumors are growths that occur in the skull’s eye socket (orbit) or on the nerve that transmits information from the eye to the brain (optic nerve). These growths are caused by the body’s cells growing out of control. Orbital and optic nerve tumors can be benign (non-cancerous) or malignant (cancerous). Malignant tumors can indicate one of several types of cancer, include meningiomas, sarcomas, and osteomas.
Both benign and malignant orbital and optic nerve tumors can create pressure on the nerves that allow the eye to function, causing vision problems. This is called optic nerve compression.
Symptoms of orbital and optic nerve tumors and optic nerve compression may include:
- Changes in vision
- Bulging or flattened appearance to the eyeball
- Eye pain or numbness
Orbital and optic nerve tumors are typically removed surgically. Endoscopic and endonasal techniques can often be used to remove or biopsy select tumors through the nose, as can traditional open approaches to the orbit in conjunction with oculoplastic surgeons.
Pineal tumors are tumors that originate in the pineal gland, a small gland deep within the brain, near the brain fluid reservoir called the third ventricle. Pineal tumors are rare. Symptoms include:
- Nausea and vomiting
- Double vision
Our experienced specialists have extensive experience treating and removing even the rarest skull base tumors using the most advanced, comprehensive treatments.
A pituitary tumor is a tumor that arises from the pituitary gland, the gland primarily responsible for regulating your hormones. The bean-sized pituitary gland is located just behind your eyes at the base of the brain.
Pituitary tumors can have a large impact on your quality of life because of the pituitary gland’s important role in regulating your body’s hormones. We treat the full range of pituitary tumors, including:
A craniopharyngioma is a noncancerous tumor that originates right above the pituitary gland. They are relatively rare, representing 2-5 percent of all primary brain tumors (brain tumors that originate in the brain). They are found in both children and adults. They may grow large before you notice any symptoms, which may include:
- Increased pressure on the brain, leading to headaches, vomiting, and balance issues
- Impaired vision
- Hormone imbalances that may cause excessive thirst, obesity or stunted growth
- Pituitary adenoma
Pituitary adenomas are slow-growing, noncancerous tumors that originate in the pituitary gland. Some pituitary adenomas produce excess hormones, while others limit hormone production. Pituitary adenomas are relatively common (occurring in one in five adults), although most never cause any problems. Symptoms may include:
- Vision loss
- Nausea and vomiting
- Hormone deficiencies that cause menstrual cycle changes and erectile dysfunction
- Unexplained weight loss or gain
- Rathke cleft cysts (RCCs)
Sinonasal tumors are abnormal growths that occur in the area of the sinuses and nasal cavity. These tumors may be benign (non-cancerous) or malignant (cancerous).
There are many types of sinonasal tumors. The MedStar Georgetown Skull Base Center provides care that is tailored to the type of sinonasal tumor detected and a patient’s individual health needs.
Examples of benign tumors include osteoma, inverted papilloma, juvenile nasopharyngeal angiofibroma. Examples of malignant tumors include esthesioneuroblastoma, sinonasal undifferentiated carcinoma (SNUC), adenoid cystic carcinoma, adenocarcinoma. The most common type of malignant sinonasal tumor is called. squamous cell carcinoma. Symptoms of sinonasal tumors may include:
- Congestion or difficulty breathing easily
- Bloody noses
- Facial swelling or pain
- Vision changes
Sinonasal tumors are typically treated through radiation, skull base surgery, or some combination of the two. Depending on the size and location of the tumor, it may be possible to remove these tumors endoscopically. Endoscopic or minimally-invasive techniques allow for removal of the tumor without making any incisions.
Make an Appointment
For more information or to make an appointment with our skull base tumor specialists, call our scheduling line:
Skull Base Team