Peritumoral Cystic Meningioma With Diagnostic Challenges: Two Case Reports and a Literature Review.

Cystic meningiomas are relatively rare and pose significant diagnostic challenges because their heterogeneous cystic architecture closely mimics gliomas or metastatic lesions. This radiological overlap creates critical diagnostic dilemmas that directly influence surgical strategy and patient counseling. We present two surgically treated cases that illustrate distinct imaging pitfalls and offer practical insights for advanced image-based differentiation. The first patient, a 45-year-old man, presented with behavioral changes and right-sided weakness; Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a heterogeneous left temporal cystic mass, initially suspected to be a cystic meningioma or metastatic tumor. The second patient experienced dizziness for one day following mild trauma; The CT and MRI showed cystic lesions at the left frontal convexity. The differential diagnoses included cystic meningioma, hemangioblastoma, metastatic tumor, brain abscess, and chronic subdural hematoma. Both patients underwent frontotemporal craniotomy, and the first case revealed a cyst containing xanthochromic fluid and distinct mural nodules attached to the dura. In the second case, the cystic component contained an organized mixed hematoma, liquefied "black oil" blood, combined with granulation tissue and a solid tumor mass. Histopathology confirmed angiomatous meningioma in the first case and atypical meningioma in the second. Despite the diagnostic complexities, both patients showed favorable postoperative recovery. These cases underscore the importance of distinguishing cystic meningiomas from other intracranial pathologies.