Skull Base Therapy

Experts in neurosurgery, otolaryngology, radiation oncology, endocrinology, ophthalmology, neuroradiology and pathology streamline and optimize care for patients who have complex skull base tumors and related conditions.

Skull Base Therapy

Experts in neurosurgery, otolaryngology, radiation oncology, endocrinology, ophthalmology, neuroradiology and pathology streamline and optimize care for patients who have complex skull base tumors and related conditions.

Our Program

The USC Skull Base Therapeutics Center at Keck Medicine of USC in Los Angeles offers state-of-the-art multidisciplinary care for patients with a variety of tumors and other conditions located at the base of the skull. At the center, experts in neurosurgery, otolaryngology, radiation oncology, endocrinology, ophthalmology, neuroradiology and pathology streamline and optimize care for patients who have complex skull base tumors and related conditions. Common conditions we treat include a variety of head and neck tumors (e.g. meningiomas, pituitary tumors, acoustic neuromas and head and neck cancers), trigeminal neuralgia, aneurysms and cerebrospinal fluid leaks.

Our Approach

The USC Skull Base Therapeutics Center combines the disciplines of several specialties with a focus on tumors and other disorders located at the base of the skull. The center’s physicians use the latest minimally invasive techniques to improve outcomes and reduce recovery times; these treatments include endoscopic neurosurgery, radiosurgery and minimally invasive approaches through natural corridors, such as the sinuses and nasal passages.

Common skull base locations we treat include:

Anterior skull base — Surgery of the anterior skull base often involves structures located toward the front of the head, including the optic nerves, optic chiasm and pituitary gland. Common lesions treated in the anterior skull base include meningiomas, pituitary tumors, Rathke cleft cysts, craniopharyngiomas, and head/neck cancers. In some cases, our surgical team approaches tumors through nasal passages (endonasal surgery) using thin endoscopes that do not require incisions on the face or head. In other instances, access to the tumor is gained through tiny holes or “keyholes” via the eyebrow or other parts of the cranium. Additionally, our team is adept at performing complex head and neck cancer operations that are followed by complex skull base reconstructions. For more information about services related to treating disorders of the pituitary gland, please visit the USC Pituitary Center website.

Lateral skull base — Surgery of the lateral skull base often involves structures located near the side of the head, including the inner ear, facial nerve and nerves that conduct hearing and balance. Common lesions treated in the lateral skull base include acoustic neuromas, meningiomas and glomus jugulare tumors. A variety of tumors of the lateral skull base are accessible through small incisions made by the ear or side of the head. Several additional techniques, including radiosurgery and minimally invasive surgery, involve approaching tumors through the ear canal or back of the head. The USC Acoustic Neuroma Center is internationally renowned for its expertise in these procedures.


Acoustic neuroma is also called vestibular schwannomas, acoustic neuromas are benign, usually slow growing tumors that arise from the balance or hearing nerve (eighth cranial nerve) and do not spread to other parts of the body. They make up 6 to 10 percent of all brain tumors and there are approximately 2,280 new cases per year in the United States. For more information, visit the USC Acoustic Neuroma Center.

Astrocytoma is a brain tumor made up of astrocytes- glial cells that support the neurons of the brain. Astrocytomas are the most common type of primary brain tumors originating from brain tissue. There are approximately 12,000 new cases of astrocytoma every year. Even the most aggressive astrocytomas almost never spread throughout the blood and lymphatic systems into other parts of the body, and in this sense, they differ from cancers in that they typically remain confined to the central nervous system. However, astrocytomas are not “benign” because they may infiltrate or invade brain tissue. There are four grades of astrocytoma, each of which require their own tailored treatment protocol.

Cholesterol granulomas are rare, benign cysts that appear in the skull, near the middle ear. The cysts are expanding masses that contain fluids, lipids and cholesterol crystals surrounded by a fibrous lining. They are often incidental and do not cause symptoms. Granulomas near the middle ear, however, can cause hearing loss as well as nerve damage.

Chordomas are very rare cancers of the spine and spinal cord. Chordomas can arise in the skull base in a bony region called the clivus, where they can cause double vision and brainstem compression. These tumors are often treated via an endonasal endoscopic approach. For more information, please visit the USC Chordoma Center.

Craniopharyngioma is a benign, yet locally invasive tumor typically located in the area of the pituitary gland. It is usually a hard tumor that can be calcified and is a remnant of a duct that develops between the brain (cranio-) and mouth (pharynx). It often grows in intimate contact with surrounding structures, such as the pituitary stalk and gland, optic nerves, ventricles of the brain and blood vessels. Patients with craniopharyngiomas often have visual loss, hormonal dysfunction, headaches, memory loss or confusion and pressure build-up in the brain (hydrocephalus). Visit our health library for detailed information on craniopharyngioma.

Epidermoids is a rare benign, tumor of skin cells that penetrated into the cranium, either through abnormal development or by trauma. They often cause headache and cranial nerve compression.

Facial nerve tumors which are either facial schwannomas (from Schwann cell) or vascular tumors, these affect the facial nerve that controls jaw and facial movement, as well as salivary function and taste on the tip of the tongue. These are benign, slow growing tumors that can cause problems with facial muscle function.

Glomus jugulare tumors are a benign tumor of the temporal bone, part of the skull close to the ears. Symptoms can include difficulty swallowing, dizziness, hearing problems, hoarseness, pain, weakness or loss of movement in the face.

Meningioma is a slow growing, usually benign tumor of the brain or spinal cord. Although these tumors usually arise from the covering of the brain (meninges) and not the brain tissue itself, they often compress the brain and other important nerves or blood vessels. Meningiomas account for 14 to 19 percent of all brain tumors. The peak incidence is 45 years of age. They are twice as common in women as men. Approximately 90-95 percent of all meningiomas are benign. Despite this, they are not always curable with surgery and some patient will require additional treatment, including radiation and radiosurgery.

Metastatic brain tumors are tumors that spread to the brain from another (primary) cancer in the body. Metastatic brain tumors are known to occur in 20 to 45 percent of cancer patients. Tumor cells often spread through the bloodstream or other routes across the blood-brain barrier and into the central nervous system. The most common primary cancers resulting in brain metastases that require treatment include lung, breast, melanoma (skin) and genitourinary tract cancers. Metastatic tumors are often treated with surgical removal and/or radiosurgery (e.g. Gamma Knife Radiosurgery).

Pituitary adenoma is a slow growing and typically benign tumor arising from cells in the pituitary gland. Because they originate from cells in the master hormone pituitary gland, they often cause problems related to hormonal dysfunction. Some pituitary tumors result in excessive production and over-secretion of hormones, which can result in a variety of syndromes. A large proportion of these tumors, however, do not produce any functional hormones, but instead grow to a size where they compress surrounding structures. Larger pituitary tumors (called macroadenomas) cause headache, visual loss and pituitary gland dysfunction. A dysfunctional pituitary gland may cause changes in energy level, sexual function and libido, and many other symptoms. These tumors are usually treated using minimally-invasive endoscopic endonasal operations. For more information, visit the USC Pituitary Center.

Other conditions where cranial base expertise is of primary importance include:

Giant or complex cerebral aneurysms – these are large weaknesses in the arterial walls in brain blood vessels. Bursting an aneurysm will result in excessive bleeding on the brain, which can be fatal.

Arteriovenous fistulae, including carotid cavernous fistulae – a defect in the walls of arteries sending blood into the brain, which can reduce needed blood flow.

Cerebrospinal fluid leaks – leakage of cerebrospinal fluid (which bathes the brain and spinal cord) into other tissues.


The USC Skull Base Therapeutics Center at Keck Medical Center of USC in Los Angeles takes an interdisciplinary approach to diagnostics, treatments and management drawing from experts including neurologists, neurosurgeons, nurses, psychiatrists, oncologists, spinal specialists and others. The center is known for its minimally invasive approaches, as well as TruBeam™ STx radiosurgery.

Endoscopic neurosurgery is a rapidly evolving subspecialty that takes full advantage of the most recent advancements in optical and video technology as well as surgical instrumentation to treat a variety of brain tumors and other conditions. The smallest incisions and bony openings possible are utilized to safely and adequately perform a given operation. Using natural anatomical corridors and smaller incisions to approach various brain regions results in decreased injury to normal brain structures, reduced risks of cerebrospinal fluid leakage and may minimize pain, risk of infection and the length of hospital stays. Recently, integration of high quality endoscopy systems and high definition viewing monitors into many types of neurosurgery has significantly improved our ability to perform many of these approaches on a daily basis. For more information, visit the USC Minimally Invasive Neurosurgery and Endoscopic Skull Base Center.

Neuro-navigation is the use of high-quality neuroimaging (such as an MRI) that is programmed into a specialized computer in the operating room and registered to the patient’s surface anatomy prior to starting the operation. The navigation device acts as a sort of global positioning satellite or “GPS” for the brain that may improve safety and minimizes the size of surgical incisions.

Radiosurgery treatment includes the TruBeam™ STx technique. For more information, visit the USC Stereotactic Radiosurgery Center.

Open craniotomy may be recommended for tumors located closer to the ventricles and above the pituitary gland. This approach allows a trajectory from above and better exposure of the optic nerves and major arteries in this region. Although the recovery time is slightly longer, an open craniotomy may be warranted for more complex tumors. The risks of a craniotomy for removal of a craniopharyngioma include worsened vision, hormonal dysfunction, diabetes insipidus, and a small risk of stroke, among others.

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