Comparative analyze MRI and pathological feature of supratentorial primitive neuroectodermal tumors

Abstract：Objective To analyze MRI feature and pathological findings of supratentorial primitive neuroectodermal tumors (sPNET) ,and improve the diagnosis .Methods The MRI findings and histopathological features of 22 cases with sPNET proved by pathology were analyzed retrospectively and combined with literature .Results Twenty cases showed single intracranial mass ,one case with diffuse lesion ,and one with multiple lesions .On MRI ,Most tumors were localized in cerebral subcortex ,presented as round or lobulated masses with well‐demarcated margins ,and with mild or no peritu‐moral edema .Large cystic and necrotic portions in tumors were seen in 15 cases ,and focal intratumoral hemorrhage were seen in 11 cases .The solid portion of tumors showed slightly hypointense to isointense on T1‐weighted images ,and isoin‐tense to slightly hyperintense on T2‐weighted images .The solid portion of tumors showed low ADC value in 13/19 cases . On post‐contrast imaging ,77 .3 percent tumors showed marked inhomogeneous enhancement .On microscopic examina‐tion ,necrosis were seen in 17 cases ,the tumors composed of small round to oval small cells with hyperchromatic nuclei and spread invasively ,some of the tumor cells appeared as rosettes .Most cases showed multiple neurogenous maker ex‐pression on immunohistochemistry assay .Conclusion The MRI appearance of sPNET could reflect its histopathology fea‐tures ,and helpful to the diagnosis and differentiation from other brain tumors .