The Mount Fuji Sign

A 53-year-old woman was admitted because of progressive right-sided hemiparesis and aphasia. A computed tomographic (CT) scan of the brain revealed a space-occupying supratentorial lesion. A biopsy through a burr hole led to the histologic diagnosis of primary B-cell lymphoma of the central nervous system. Systemic treatment with corticosteroids and methotrexate was initiated, resulting in clinical stabilization. Six weeks later, the patient became disoriented and lethargic. A second CT scan of the brain showed a massive accumulation of air that was compressing the frontal lobes, a condition called the Mount Fuji sign. Dark-to-black areas in the frontal region were caused . . .