Conventional and advanced MR imaging findings of primary Ewing sarcoma of the tentorium: a case report with literature review

Background: Primary intracranial Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) is an extremely uncommon tumor. Care should be taken as it can be mistaken for a meningioma radiologically. Case description: This paper reports a case of a 44-year-old male presenting with headache. A magnetic resonance imaging demonstrated a mass involving the tentorium, cerebrum and cerebellum with solid-cystic component. The solid component was hyperintense on T1-weighted images with significant enhancement. There was restriction in diffusion-weighted images and microhemorrhagic signal change in susceptibility weighted images. MR perfusion revealed increased relative cerebral blood volume and mean transit time values. Surgical pathology was reported as ES. Conclusions: Intracranial ES/pPNET is a rare tumor that generally arises from the meninges. It must be distinguished from meningioma since it can be mistaken radiologically, because the treatment and prognosis are quite different. Localization and conventional MR signal characteristics of both lesions are similar. Whereas, MR perfusion findings may be helpful in discrimination.