Pleomorphic xanthoastrocytoma:the features of clinic, pathology and MRI in 8 cases and literature review

Objective: To analyze the MRI features of brain pleomorphic xanthoastrocytomas(PXA) in 8 cases for improving its clinical,pathological and MRI features understanding.Methods: The MRI plain scans,enhanced scans and DWI were explored in 8 cases with brain PXA diagnosed by pathology,and the MRS combined with PWI were examined in 2 cases.Results: Three patients were male and 5 patients were female,the age of all patients ranged from 14 to 56 years old(including 6 patients less than 25 years old).Interstitial change in 2 cases were found.Single lesion in 7 cases and single lesion complicated with round multiple lesions in 1 case with interstitial change were found.Five cases located or involved in temporal lobe,6 cases located in the cortex and subcortical region.Solid-cystic tumors in 5 cases and solid tumors in 3 cases(including 1 case with partial pia mater invasion,1 case with bleeding and ependymal invasion and 1 case with lateral ventricle spread) were identified by MRI.The tumor solid area showed slightly hypointense on T1-weighted images,slightly hyperintense on T2-weighted images and marked enhancement.The difference between the apparent diffusion coefficient value and subcortex alba was not statistical significance(P>0.05).The solid-cystic capsule wall enhanced in 2 cases.The light to moderate degree edema around the tumor were detected in all tumors.The significant increasing Cho peak and decreasing N-acetyl aspartic acid peak and Lip peak were found in tumor solid area with high perfusion.Conclusions: PXA occurres usually in adolescent,which locates the brain shallow position of the temporal lobe.The tumor pathologic and genetic characteristics are different from other astrocytomas,complete surgical excision is important for a good prognosis.The conventional magnetic resonance imaging,magnetic resonance perfusion weighted imaging and magnetic resonance spectroscopy of PXA have certain characteristics.