A Rare Presentation of Intraparenchymal Schwannoma Mimicking as Pilocytic Astrocytoma: A Case Report

Abstract Intraparenchymal schwannomas are rare tumors, accounting for less than 1% of all intracranial schwannomas. Their radiological resemblance to common glial tumors, such as pilocytic astrocytomas, often makes preoperative diagnosis challenging. We report the case of a 27-year-old male with no prior comorbidities who presented with two episodes of new-onset generalized tonic-clonic seizures. Magnetic resonance imaging revealed a large right frontal cystic lesion with a mural nodule, radiologically mimicking a pilocytic astrocytoma. The patient underwent awake craniotomy with gross total resection. Histopathology demonstrated characteristic biphasic Antoni A and B patterns, with strong S100 and SOX-10 positivity, confirming a World Health Organization grade 1 schwannoma. His recovery was uneventful, and he was discharged on the first postoperative day without any neurological deficits. This case highlights the importance of considering intraparenchymal schwannoma in the differential diagnosis of cystic intra-axial brain lesions in young adults. Timely recognition and surgical excision are crucial for favorable outcomes.