Pleomorphic Xanthoastrocytoma (PXA)
Last Updated: March 27, 2020
- Supratentorial cortical/peripheral astrocytic tumor
- WHO II
- Astrocyte pleomorphism and lipid-containing cells
- May show anaplastic features (10-15%)
- Malignant transformation in minority of cases
- Typically afflicts children and young adults (10-36 years; mean 26 years)
- No gender predilection
- Commonly presents with seizures, often of temporal lobe origin
- Overall good prognosis
- 10-year survival 70%
- Extent of tumor resection and mitotic index important prognostic factors
- Younger patient age and BRAF mutations associated with better prognosis
- Hemispheric tumor often located peripherally with cortical ± leptomeningeal involvement
- Temporal lobe > frontoparietal > occipital
- Classically cystic with solid mural nodule; nodule often abuts pial surface
- May have enhancing dural tail of leptomeningeal attachment
- Often with infiltration of adjacent parenchyma beyond margin of visible tumor
- ± adjacent cortical dysplasia
- Hypodense cystic component; iso- to hyperdense mural nodule or solid components
- Minimal to moderate adjacent edema
- Calcification and hemorrhage uncommon
- Strong enhancement of mural nodule/solid components on contrast-enhanced CT
- T1WI: solid component iso- to hypointense to gray matter; cystic component isointense to CSF
- T2WI: solid component iso- to hypointense to gray matter; cystic component isointense to CSF; minimal-to-moderate surrounding T2-hyperintense vasogenic edema
- FLAIR: heterogeneous signal intensity
- DWI: solid components may show diffusion restriction
- T1WI+C: generally strong enhancement; sometimes enhancing dural tail/leptomeninges
- MR with contrast including coronal images for temporal lobe evaluation
For more information, please see the corresponding chapter in Radiopaedia.
Contributor: Rachel Seltman, MD
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Ida CM, Rodriguez FJ, Burger PC, et al. Pleomorphic xanthoastrocytoma: natural history and long-term follow-up. Brain Pathol. 2015;25:575-586
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK, Burger PC, Jouvet A, et al. The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol. 2007;114:547.
Moore W, et al. Pleomorphic xanthoastrocytoma of childhood: MR imaging and diffusion MR
Osborn AG, Salzman KL, Jhaveri MD. Diagnostic Imaging (3rd ed). Philadelphia, PA: Elsevier, 2016.
Yu S, He L, Zhuang X, et al. Pleomorphic xanthoastrocytoma: MR imaging findings in 19 patients. Acta Radiol. 2011;52: 223-228.
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