A subependymoma is a type of brain tumor; specifically, it is a rare form of ependymal tumor. They are usually in middle aged people. Earlier, they were called subependymal astrocytomas.
The prognosis for a subependymoma is better than for most ependymal tumors, and it is considered a grade I tumor in the World Health Organization (WHO) classification.
They are classically found within the fourth ventricle, typically have a well demarcated interface to normal tissue and do not usually extend into the brain parenchyma, like ependymomas often do.
Symptoms and signs
Patients are often asymptomatic, and are incidentally diagnosed. Larger tumours are often with increased intracranial pressure.
These tumours are small, no more than two centimeters across, coming from the ependyma. The best way to distinguish it from a subependymal giant cell astrocytoma is the size.
The diagnosis is based on tissue, e.