NeuroradiologyPleomorphic xanthoastrocytoma
distinct slow growing,
benign astrocytoma subtype (see
astrocytoma) characteristically superficially located in the
cerebral hemispheres, mainly in the
temporal lobe.
On gross pathology these tumours are typically well demarcated, partially cystic tumours with a mural nodule of different sizes. The surrounding parenchyma is rarely infiltrated.
On microscopic examination, characteristic foamy lipid-laden xanthomatous astrocytes are found, mixed with other cell types like multi-nucleated giant cells, spindle shaped cells and rare endothelial cells. Mitotic figures and necrosis are rare.
They are found in young adults with a history of seizures; they are rare in children. They can be totally removed surgically but about 1020% may have recurrent malignant degeneration.
At CT an enhancing mural nodule with an associated cyst is the most frequent finding. MR shows a similar picture. Sometimes the tumour is solid and enhances markedly; differential diagnosis involves pilocytic astrocytoma and ganglion cell tumour (see ganglioglioma, ganglioneuroma).
GS