What is ependymoma?
Ependymoma is a rare type of primary brain or spinal cord tumor. Primary brain and spinal cord tumors are a type of tumor that starts in the central nervous system (CNS).
These tumors are classified according to the presumed cell of origin. The most common types of cells in the nervous system are neurons and glial cells, although tumors from neurons are rare. Glial cells are the supportive cells of the brain and tumors arising from these cells are called gliomas. Subtypes of glial cells of the CNS include:
- Astrocytes cells
- Oligodendrocytes cells
- Ependymal cells
The World Health Organization (WHO) Classification of Tumors of the CNS recognizes brain tumors that are associated with all three types of glial cells, such as astrocytomas, oligodendrogliomas and ependymomas.
How do ependymomas form? Do they spread?
Ependymomas are a rare type of glioma that are thought to develop from precursor cells to the ependymal cells that line the ventricles (fluid-filled spaces in the brain) and the central canal of the spinal cord. Ependymomas can occur anywhere in the CNS, including the brain or the spinal cord. Occasionally, ependymoma tumor cells can spread in the cerebrospinal fluid (CSF) and involve multiple areas in the brain, spine, or both. Although it is very rare for the tumor to spread to other parts of the body, it has been reported to occur in rare instances, but spread within the CNS is more common. Typically, tumor nodules form where the tumor cells settle such as the base of the brain and the bottom of the spinal cord.
Who does ependymoma effect?
Ependymomas can occur in both children and adults. They represent three to six percent of all CNS tumors in adults.
The incidence of ependymomas is higher in children than in adults. They are the third most common form of pediatric brain tumors of the CNS, and the majority of these tumors occur in young infants and children. In children, these tumors are most commonly found in the brain, and in particular in the posterior fossa.
For adults, ependymomas account for five percent of adult gliomas with the majority occurring in the spine. Currently, the Surveillance Epidemiology and the End Results (SEER) Program and the Central Brain Tumor Registry (CBTRUS) group all grades of ependymomas together for reporting purposes.
According to a CBTRUS report on incidence rates between 1998 and 2002, 1,126 ependymomas and anaplastic ependymomas were diagnosed for an adjusted rate per 100,000 person-years of 0.26. This rate is slightly higher in males (0.29) than females (0.22), and in whites (0.27) versus blacks (0.12).
CERN is compiling one of the largest databases of adult and pediatric ependymoma tissue to evaluate differences based on grade, location and symptom presentation, to improve our understanding of ependymoma and to improve diagnosis and our understanding of the prognosis for individuals diagnosed with ependymoma.