Carcinoma metastasis mimicking meningioma

The scientific approach to dural metastases mimicking meningiomas holds significant relevance, as these cases pose considerable challenges to clinicians in routine practice. Differentiating between these two distinct pathologies is critical, particularly when conservative management is considered for patients diagnosed with non-surgical meningiomas. Misdiagnosis in such scenarios can lead to detrimental outcomes for the patient, underscoring the need for vigilant follow-up in cases exhibiting suspicious imaging patterns. While biopsy could provide definitive diagnosis in uncertain cases, it is often avoided due to its inherent risks, especially in elderly patients and in cases where the meningiomas are located in surgically challenging regions. Consequently, most conservatively managed cases are presumed to be typical meningiomas, and invasive diagnostic measures are typically not pursued unless absolutely necessary [1]. However, carcinomas from various primary sites including the breast, prostate, gallbladder, larynx, and less commonly, Ewing’s sarcoma or melanoma can rarely present as dural metastases, especially in the parasagittal convexity [2,3,4]. These metastases can closely mimic meningiomas both clinically and radiologically. A study of 1,000 meningioma cases diagnosed between 2004 and 2010 revealed that 20 (2%) were ultimately found to mimic, with histological diagnoses including gliosarcoma, Rosai-Dorfman disease, hemangiopericytoma, osteosarcoma, medulloblastoma, adenocarcinoma, and nonseminomatous germ cell tumours [5]. Among these, adenocarcinomas are the most common metastatic tumours mimicking meningiomas. These lesions, like meningiomas, exhibit attachment to the dura, a dural tail, and contrast enhancement [6]. Such imaging characteristics can make distinguishing metastatic tumors from meningiomas exceedingly difficult using standard neuroimaging techniques [7,8]. Even intraoperatively, dural metastases can appear identical to meningiomas, complicating diagnosis further [4]. Both conditions may share features such as a solid structure, limited diffusion of water molecules, extensive peritumoral edema, and similar contrast enhancement patterns [9]. The pathways for metastatic spread include arterial and venous routes, particularly via Batson’s venous plexus [10]. Cases of cerebrospinal fluid (CSF) dissemination have not been described. This report describes three cases of dural metastases mimicking meningiomas, with locations including the temporal region, the cavernous sinus, and the cervicothoracic dura.