Primary central nervous system lymphomas (PCNSL) represent only 1% of all non-Hodgkin's lymphomas (NHLs). A 66 year-old woman was hospitalized due to multiple episodes of syncope and seizures which occurred the week before admission to the hospital. A computerized tomography (CT) scan of the brain showed a right parietal lesion suggesting a subdural effusion. The patient was operated and a dural lesion extending to the epidural space and cerebral cortex was excised. Histologic findings suggested diagnosis of a low-grade lymphoma of the mucosa associated lymphoid tissue (MALT) type. The patient was treated with radiation therapy and has now completely recovered 12 months after surgery.