Multiple myelomas (MM) are characterized by monoclonal proliferation of immunoglobulin (Ig)-secreting plasma cells. Central nervous system involvement is a rare complication of MM, and it can present as either an intraparenchymal or a leptomeningeal lesion. A 77-year-old woman was transferred from the dementia clinic in July 2012. She had a large heterogeneous signal mass with central necrosis and with pial involvement in the left frontal lobe with destruction of the frontal bone that was observed on computed tomography and magnetic resonance imaging. Multiple punched out radiolucent lesions were also noted on the skull X-ray. Serum protein electrophoresis revealed an IgA-kappa monoclonal gammopathy. External lumbar drainage was helpful for treating the fluid collection underneath the scalp after an orbitozygomatic craniotomy with duroplasty.