The skull base is the area behind the eyes and nose that slopes down to the back of the head. It forms the floor, or base, of the skull. The spinal cord, multiple nerves and the major blood vessels of the brain, head and neck pass through openings in the skull base.
The term “skull base tumor” refers to the tumor’s location. The type of cancer cell can be one of several. Some are malignant (cancer), and some are benign (non-cancerous). Even benign tumors can cause problems because they are growing in a confined space.
Skull Base Tumor Types
Skull base tumors are grouped by location and the type of cells in the tumor. Where a skull base tumor begins can make a difference in the type of cancer cells. Location also can influence symptoms and treatment.
Skull base tumors may start from:
- Areas below the skull base, such as the nasal sinus or inner ear
- Brain tumors that grow down toward the skull base
- The bones of the skull base
Benign skull base tumor types include:
- Pituitary adenoma
- Acoustic neuroma (also called vestibular schwannoma)
- Glomus tumors (also called paraganglioma, glomus tympanicum, glomus jugulare, carotid body tumor)
- Neuroma (trigeminal neuroma, vagal schwannoma)
Malignant skull base tumor types include:
- Carcinomas (squamous cell, basal cell, adenoid cystic, adenocarcinoma)
- Sarcomas (chondrosarcoma, rhabdomyosarcoma, osteosarcoma)
- Carcinoid (neuroendocrine carcinoma)
- Mucosal melanoma
Skull Base Tumor Risk Factors
Anything that increases your chance of getting a skull base tumor is a risk factor. Since skull base tumors are rare, risk factors are hard to determine.
Sometimes, inherited genetic conditions are linked to skull base tumors. In these cases, our genetics experts are part of the patient’s care team. The types of tumors that may be caused by genetic conditions include:
Bilateral acoustic neuromas, as well as other brain and spine tumors, may be caused by the genetic disorder neurofibromatosis type 2.
Paragangliomas (also called glomus tumors or carotid body tumors) may be caused by a familial predisposition for other tumors.
Not everyone with risk factors gets skull base tumors. However, if you have risk factors, it’s a good idea to discuss them with your doctor.
Research shows that many cancers can be prevented.
Some cases of skull base tumors can be passed down from one generation to the next. Genetic counseling may be right for you. Learn more about the risk to you and your family on our genetic testing page.