Ewing's sarcoma in the left lateral ventricle:a case report

YUAN Xu; MAO Ping; GAO Ke; WANG Tuo

doi:10.13798/j.issn.1009-153X.2025.04.014

Abstract：Intracranial Ewing sarcoma,also known as primitive neuroectodermal tumor(PNET),is a rare and highly malignant neoplasm originating from neuroectoderm,predominantly occurring in the parietal and frontal bones.This report describes a case of Ewing sarcoma in the left lateral ventricle of a 40-year-old male who presented with a 15-day history of dizziness and headache.Preoperative brain MRI revealed a large oval-shaped heterogeneous mass(approximately 7.0 cm×3.0 cm×3.0 cm)in the body and posterior body of the left lateral ventricle,predominantly solid with a cystic component.The solid portion exhibited isointensity on T1-weighted imaging and moderate hyperintensity on T2-weighted imaging,demonstrating marked contrast enhancement.The cystic component showed hypointensity on T1-weighted and hyperintensity on T2-weighted sequences without enhancement.The lesion extended into the right lateral ventricular body,compressing the adjacent left temporal and parietal lobes.Initial radiological suspicion favored intraventricular meningioma.MR spectroscopy demonstrated elevated Cho/NAA and Cho/Cr ratios with a diminished NAA peak.Following preoperative preparation,craniotomy for tumor resection was performed.Histopathological examination confirmed the diagnosis of Ewing sarcoma.Postoperative MRI at 3 months showed no evidence of recurrence.At the 9-month follow-up,the patient remained neurologically intact with normal muscle strength and tone in all extremities.The management of this case indicates that imaging features of intraventricular Ewing sarcoma overlap with meningioma,posing diagnostic pitfalls,and Characteristic MRS findings provide crucial discriminative clues.Ewing sarcoma should be included in differential diagnoses for intraventricular cystic-solid masses,and total resection remains cornerstone for tumor control,warranting long-term surveillance for recurrence.