Primary intracranial Ewing-like sarcoma presenting with rapid bilateral blindness: A case report

Abstract

Primary intracranial Ewing sarcoma / Ewing-like sarcoma is an exceptionally rare malignant small round cell tumor. Its radiological appearance is often non-specific and may mimic other aggressive intracranial neoplasms, leading to diagnostic delay. We report the case of a young adult presenting with progressive headaches and recurrent generalized tonic-clonic seizures for six months, followed by rapid bilateral visual loss. Neurological examination revealed papilledema and decreased visual acuity, prompting brain imaging. MRI demonstrated a large aggressive frontal mass with heterogeneous enhancement, marked diffusion restriction, meningeal involvement, and significant mass effect with midline crossing. Initial staging showed no extracranial disease. Histopathology revealed a small round cell tumor with strong membranous CD99 expression consistent with an intracranial Ewing-like sarcoma. The patient received multimodal treatment including radiotherapy and VDC/IE chemotherapy. Follow-up imaging demonstrated partial tumor response. However, no visual recovery occurred, and the patient remained limited to light and shadow perception. This case highlights the diagnostic challenges of primary intracranial Ewing-like sarcoma and its potential to present with severe and irreversible visual impairment. Early neuroimaging in patients with persistent seizures is essential to avoid diagnostic delay, and molecular confirmation remains crucial for future cases.