Ependymoma¶

Definition¶

Ependymoma is the most common intramedullary spinal cord tumor in adults, arising from ependymal cells lining the central canal. It is typically a well-circumscribed, slow-growing tumor that arises centrally within the cord and often has a surgical cleavage plane, making gross total resection possible.

Imaging Findings¶

MRI¶

Location — Intramedullary, centrally located within the cord. Most common in the cervical cord and cervicothoracic junction.
T1-weighted — Isointense to slightly hypointense
T2-weighted — Hyperintense, well-defined margins
Enhancement — Intense, homogeneous enhancement (a key distinguishing feature from astrocytoma)
Hemosiderin cap — Low T2 signal "cap" at the superior and/or inferior poles of the tumor, representing prior microhemorrhages. This is a highly characteristic finding of ependymoma.
Intratumoral cysts — Common; appear as T2-bright, non-enhancing areas within the tumor
Associated syrinx — Reactive syrinx may be present at the poles
Cord expansion — Usually over 3–4 vertebral segments (shorter than astrocytoma)

CT¶

Not the primary modality; may show cord expansion on CT myelography

Clinical Pearl

The hemosiderin cap — a rim of T2-dark signal (GRE/SWI accentuated) at the poles of an intramedullary tumor — is highly suggestive of ependymoma. It results from the tumor's tendency to bleed at its margins. Combined with central cord location, well-defined margins, and homogeneous enhancement, this is a near-pathognomonic combination.

Spinal ependymoma MRI — Cervical spinal cord ependymoma in a 17-year-old with NF2. Sagittal T2-weighted images showing cystic areas, with post-contrast images demonstrating enhancement of the solid tumor components and expansion of the cervical cord. (Source: Defined et al., Front Pediatr, 2023. CC BY 4.0)

Subtypes¶

Cellular ependymoma (WHO grade II) — The most common subtype in the cervical cord
Myxopapillary ependymoma — A distinct variant occurring at the conus medullaris and filum terminale (see Myxopapillary Ependymoma)
Anaplastic ependymoma (WHO grade III) — Rare, more aggressive

Management¶

Gross total resection is the treatment of choice and is often achievable due to the cleavage plane between tumor and cord
Radiation therapy for incomplete resection or recurrence
Long-term surveillance MRI is essential (recurrence can occur years later)

Key Points¶

Most common intramedullary tumor in adults
Central cord location, well-defined margins, homogeneous enhancement
Hemosiderin cap is highly characteristic
Gross total resection is often achievable (unlike astrocytoma)
Myxopapillary ependymoma is a distinct subtype at the conus/filum

References¶

Karsonovich T, Hall WA. Ependymoma. In: StatPearls. Treasure Island (FL): StatPearls Publishing; updated 2025 Nov 13. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538244/
Davidson CL, Das JM, Mesfin FB. Intramedullary Spinal Cord Tumors. In: StatPearls. Treasure Island (FL): StatPearls Publishing; updated 2024 Jun 7. Available from: https://www.ncbi.nlm.nih.gov/books/NBK442031/
Cerretti G, et al. Spinal ependymoma in adults: from molecular advances to new treatment perspectives. Front Oncol. 2023;13:1301179. Available from: https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2023.1301179/full
Yuh EL, Barkovich AJ, Gupta N. Imaging of ependymomas: MRI and CT. Childs Nerv Syst. 2009;25(10):1203–13. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC2744772/
Choi JY, Chang KH, Yu IK, Kim KH, Kwon BJ, Han MH, Kim IO. Intracranial and spinal ependymomas: review of MR images in 61 patients. Korean J Radiol. 2002;3(4):219–28. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC2713843/
Spinal ependymoma. Radiopaedia.org. Available from: https://radiopaedia.org/articles/spinal-ependymoma