Intracranial Marginal Zone B-Cell Lymphoma Mimicking Meningioma

BACKGROUND: Marginal zone B-cell lymphoma of the meninges is a rare pathologic subtype of central nervous system lymphoma that can mimic the radiologic appearance of meningioma. CASE DESCRIPTION: We present a unique case of a 57-year-old man who presented with neurologic symptoms of severe headache, memory loss, mental status changes, and depression. Subsequent magnetic resonance imaging of the brain demonstrated an enhancing mass tracking along the anterior falx and anterior skull base with extension into the ethmoid sinus, which was radiographically consistent with meningioma. However, pathologic examination revealed numerous sheets of plasma cells and plasmacytoid lymphocytes that were immunopositive for CD20. These combined features were indicative of marginal zone B-cell lymphoma. No evidence of systemic disease was found. CONCLUSIONS: Although rare, marginal zone B-cell lymphoma must be considered in the differential diagnosis of an extra-axial enhancing mass. We review the contemporary literature and discuss preoperative radiologic differentiation of these 2 very different histopathologies.