Bilateral Frontal Lobe Vasogenic Edema Resulting from Hypertrophic Pachymeningitis due to Granulomatosis with Polyangiitis

A 61-year-old woman presented with a 1-month history of decreased activities of daily living. Magnetic resonance imaging revealed abnormal intensities of the bilateral frontal lobes and enhancement of the thickened dura matter. A biopsy of the dura mater revealed multinucleated giant cells. She had sinusitis and hematuria; she was diagnosed with granulomatosis with polyangiitis. Hypertrophic pachymeningitis (HPM) was considered to have interrupted the venous flow and caused vasogenic edema. Bilateral frontal lobe edema resulting from HPM due to granulomatosis with polyangiitis has not been reported. A biopsy and examination for other organ complications were useful for the diagnosis and treatment of our patient.