Ependymoma
Pronunciation: ep-en-DIE-moh-mah
A glial tumour arising from ependymal cells lining the ventricular system and central canal of the spinal cord, the most common spinal cord tumour in children.
Full Definition
Ependymomas are neoplasms of ependymal lineage classified under the WHO Classification of Tumours of the Central Nervous System. In pediatric pathology, they most commonly arise in the posterior fossa (particularly the fourth ventricle) and are graded I–III, with grade III (anaplastic ependymoma) carrying the worst prognosis. The 2021 WHO CNS5 classification introduced molecular subgroups—including ZFTA fusion-positive and YAP1 fusion-positive subtypes—that significantly influence prognosis and treatment beyond histological grade. Editors must be aware that the preferred spelling is 'ependymoma' (not 'ependioma') and that grading and molecular subtype designations follow WHO CNS5 conventions in contemporary reports.
Usage
Usage note: Always document WHO grade and, in contemporary reports, the molecular subtype designation per WHO CNS5; grading alone is insufficient for current clinical management.
In Context
- "The resected posterior fossa mass was classified as WHO grade III ependymoma, ZFTA fusion-positive subtype." — Neuropathology report
- "The author incorrectly spelled the diagnosis as 'ependioma,' which was corrected during copy-editing." — Pediatric oncology case report