Astrocytoma¶
Definition¶
Spinal cord astrocytoma is the second most common intramedullary spinal cord tumor in adults and the most common in children. It arises from astrocytes within the spinal cord substance and tends to be infiltrative, making complete surgical resection difficult. The majority are low-grade (WHO grade I–II), but high-grade variants (anaplastic astrocytoma, glioblastoma) do occur.
Imaging Findings¶
MRI¶
- Location — Intramedullary; the spinal cord is expanded over multiple segments. Most common in the thoracic cord and cervicothoracic junction.
- T1-weighted — Isointense to slightly hypointense relative to normal cord. May be difficult to distinguish from normal cord without contrast.
- T2-weighted — Hyperintense, often with poorly defined margins reflecting the infiltrative nature
- Enhancement — Variable and often patchy or heterogeneous. Low-grade astrocytomas may show minimal or no enhancement. High-grade tumors enhance more avidly.
- Associated syrinx — Reactive syrinx (non-neoplastic cyst) may be present at the poles of the tumor, but tumor-associated cysts are less common than in ependymoma
- Cord expansion — Over a long segment (typically 4–7 vertebral levels)
- Edema — Surrounding edema may extend beyond the tumor margins, making it difficult to determine the true extent of the neoplasm
Key Distinguishing Features from Ependymoma¶
| Feature | Astrocytoma | Ependymoma |
|---|---|---|
| Position in cord | Eccentric | Central |
| Margins | Infiltrative, ill-defined | Well-defined |
| Enhancement | Patchy, heterogeneous | Homogeneous |
| Hemorrhage (hemosiderin cap) | Uncommon | Common |
| Cyst | Polar reactive syrinx | Intratumoral cysts common |
| Resectability | Difficult (infiltrative) | Often possible (cleavage plane) |
| Age | More common in children | More common in adults |
Clinical Pearl
The key distinction between intramedullary astrocytoma and ependymoma on MRI is the enhancement pattern and margins. Astrocytomas enhance patchily with ill-defined margins (reflecting their infiltrative nature), while ependymomas enhance homogeneously with well-defined margins and often have hemosiderin caps from prior microhemorrhages. This distinction matters because ependymomas are usually resectable while astrocytomas are not.
Management¶
- Low-grade astrocytomas — Biopsy and/or limited resection; observation with serial MRI
- High-grade astrocytomas — Maximal safe resection followed by radiation ± chemotherapy
- Complete resection is rarely achievable due to infiltrative growth
Key Points¶
- Most common intramedullary tumor in children
- Eccentric within the cord, infiltrative margins, patchy enhancement
- Long-segment cord expansion (typically 4–7 levels)
- Complete resection is usually not possible due to infiltrative nature
- Distinguish from ependymoma by margins, enhancement pattern, and hemosiderin cap
References¶
- Shih RY, Koeller KK. Intramedullary Masses of the Spinal Cord: Radiologic-Pathologic Correlation. RadioGraphics. 2020;40(4):1125-1145. doi:10.1148/rg.2020190196.
- Smith AB, Soderlund KA, Rushing EJ, Smirniotopoulos JG. Radiologic-pathologic correlation of pediatric and adolescent spinal neoplasms: Part 1, Intramedullary spinal neoplasms. AJR Am J Roentgenol. 2012;198(1):34-43. doi:10.2214/AJR.10.7311.
- Seo HS, Kim JH, Lee DH, Lee YH, Suh SI, Kim SY, Na DG. Nonenhancing intramedullary astrocytomas and other MR imaging features: a retrospective study and systematic review. AJNR Am J Neuroradiol. 2010;31(3):498-503. doi:10.3174/ajnr.A1864.
- Ogunlade J, Wiginton JG 4th, Elia C, Odell T, Rao SC. Primary Spinal Astrocytomas: A Literature Review. Cureus. 2019;11(7):e5247. doi:10.7759/cureus.5247.
- Azad TD, Pendharkar AV, Pan J, Huang Y, Li A, Esparza R, et al. Surgical outcomes of pediatric spinal cord astrocytomas: systematic review and meta-analysis. J Neurosurg Pediatr. 2018;22(4):404-410. doi:10.3171/2018.4.PEDS17587.
- Gaillard F, et al. Spinal astrocytoma. Radiopaedia.org. https://radiopaedia.org/articles/spinal-astrocytoma. Accessed May 13, 2026.