Posterior Fossa Tumors

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Found near the brain stem and cerebellum, the posterior fossa is a small space in the skull. If a tumor grows in this area, it can partially or completely block the flow of spinal fluid and cause increased pressure on the brain and spinal cord.

Because of their proximity to the cerebrum, which controls movement, posterior fossa tumors can be very serious. The physicians at the Florida Hospital Brain and Spinal Cancer Program will monitor these tumors closely. Emergency surgery may need to be performed to address the posterior fossa tumor.

Common types of posterior fossa tumors include:

• Primary neuroectodermal (new-ro-eck-toe-der-mal) tumors: This type of tumor, often called PNET for short, include medulloepitheliomas, pigmented medulloblastomas, ependymoblastomas, pineoblastomas, and cerebral neuroblastomas.
• Medulloblastoma (med-dull-oh-blast-toe-mah): Often described as a separate form of posterior fossa tumor, medulloblastoma is actually a type of PNET. More common in children, it accounts for only 1% of adult cancer diagnoses.
• Hemangioblastoma (he-man-gee-oh-blast-toe-mah): Believed to be associated with von Hippel-Lindau disease, hemangioblastomas account for 7-12% of all posterior fossa tumors. This type of tumor is most often found in patients between the ages of 30 and 40. Men are more likely to be diagnosed with it than women.
• Metastatic tumors: These tumors begin in other parts of the body, such as the breast, lung, skin or kidney and spread to the brainstem or cerebellum.
• Schwannoma (shwa-no-mah): Also known as neurilemmoma, this is a benign nerve sheath tumor that involves the Schwann cells. These cells normally produce the sheath that insulates the peripheral nerves. The tumors are relatively slow growing and are almost always benign. Only 1% become malignant, turning into a cancer known as malignant peripheral nerve sheath tumor, malignant schwannoma or neurofibrosarcoma.