ependymoma
Meaning of ependymoma: A tumor growing from the lining of the brain's fluid spaces, able to shed cells into that fluid and settle further down.
Definition of ependymoma
Ependymoma is a tumor that grows from ependymal cells, the thin layer lining the fluid-filled cavities of the brain and the narrow central canal of the spinal cord. It can arise anywhere along that lining. Because it sits directly in the path of circulating fluid, it may block drainage or release cells that travel in the fluid and take root elsewhere.
Where does it form?
| Location | Who it affects most | Usual first signs |
|---|---|---|
| Back of the brain, near the fourth ventricle | Children | Headache, vomiting, unsteadiness |
| Upper parts of the brain | Children and adults | Seizures, weakness, personality change |
| Spinal cord | Adults | Back pain, numbness, weakness |
Why does it cause pressure symptoms?
Cerebrospinal fluid is made continuously inside the brain and must flow through narrow channels before it is absorbed. A tumor sitting in one of those channels acts as a plug. Fluid keeps arriving and cannot leave, the cavities swell, and pressure inside the skull climbs. That produces headache that is worse on waking, vomiting, and in a young child a head that grows faster than expected. Relieving the blockage, sometimes by diverting the fluid along a tube, is often the first priority.
Why is the whole spine imaged?
Cells shed from the tumor can drift downward in the fluid and settle on the spinal cord or its coverings, forming what are called drop deposits. These are not a separate cancer; they are the same tumor carried to a new site. For that reason the spine is scanned and the fluid examined at diagnosis, since finding a deposit changes the plan for treatment.
How is it graded and treated?
Grading runs from slow-growing forms to anaplastic tumors with rapidly dividing cells, and molecular features are now used alongside appearance to separate groups that behave differently even within the same grade. Removing the tumor completely is the single factor most strongly linked to a better outcome, so surgery aims for total removal where the position allows it. Radiation to the tumor bed commonly follows, and this brain tumor responds less predictably to chemotherapy than several others.
Also known as
Used in a sentence
Imaging of the neural axis was performed after an ependymoma was identified in the fourth ventricle.
Good to know
Cells can spread through the cerebrospinal fluid and settle along the spinal cord, so imaging of the whole neural axis forms part of the assessment.
Word origin
Where “ependymoma” comes from
From the Greek ependyma, meaning an outer garment or wrapping, describing the lining layer, with the suffix -oma for a tumor.