Meningeal Metastases Presenting as Extra-Axial Hematoma: A Diagnostic Pitfall

Abstract

Aims: To illustrate a significant diagnostic pitfall where meningeal metastases mimic benign extra-axial hematomas, and to highlight the crucial role of contrast-enhanced magnetic resonance imaging (MRI) in achieving the correct diagnosis. Presentation of Case: We report two cases. The first is a 44-year-old female with breast carcinoma whose dural metastases presented on computed tomography (CT) as an enhancing dural-based mass. The second is a 38-year-old male with colorectal cancer whose dural metastasis appeared on CT as a collection suggestive of a subacute hematoma. In both cases, MRI was crucial in rectifying the diagnosis by revealing features of a hypercellular neoplasm. Both patients had a poor outcome, with rapid clinical deterioration despite intervention. Discussion: The radiological presentation of meningeal metastases can be deceptive. Key MRI findings that argue for a neoplastic process include marked diffusion restriction and nodular dural enhancement. Conclusion: The possibility of meningeal metastases should be considered in the differential diagnosis of any new extra-axial collection in patients with a known history of malignancy. Contrast-enhanced MRI is indispensable to differentiate these lesions and guide appropriate management.