Pleomorphic Xanthoastrocytoma

We have FLAIR, T1, T2, postcon sag T1 and precon sag T1. The patient was in mid 20's with a history of seizures. The lesion is located near/on the surface of the supratentorial brain. It is cystic with a mural nodule. The nodule is slightly low to brain on T1 and slightly bright to brain on T2 with a avid enhancement.



Differential includes - Meningioma (because the lesion is difficult to exclude that it is not extraaxial), DIG (but the patient is way too old), ganglioglioma, Pleomorphic xanthoastrocytoma, pilocytic astrocytoma, metastasis and oligodendroglioma.



Taking history, age and characteristic imaging appearance the most likely a pleomorphic xanthoastrocytoma.

• This is a rare tumor (1% of all brain tumors)


• Wide age range in literature - but most in late teens and early 20's


• WHO II - but often recurs and not sensitive to chemo or rads


• Tx - surgery; If recurs - surgery


• Classic appearance - cystic mass with mural nodule that is adjacent to the leptomeninges


• However - 52% in literature - no cystic component


• Temporal > parietal > frontal > occipital; (10% in more than one lobe)


• CT - iso or hypoattenuating lesion on noncon


• CT - calcs rare; rare to have erosion of skull or lytic lesions


• T1 - iso to hypo to gray matter


• T2 - slightly bright or iso to gray


• T1 post con - avid enhancement


• 71% of one series - had involvement of leptomeninges hence can be confused with a meningioma


• The peripheral component is single most common feature

Reference - There is an excellent reference to superficial gliomas from the AFIP http://radiographics.rsnajnls.org/cgi/content/full/21/6/1533?eaf - highly recommend reading it.

Images are from Rob's Radiology - please don't take without permission.