We describe a lupus flare in a 59-year-old woman who presented with pancytopenia, nephritis, severe renal dysfunction and marked hyperferritinemia. The course of the disease was further complicated by an iron-laden, intraspinal ancient schwannoma that compressed the cervical cord mimicking a lupus-related myelopathy and was removed surgically. Treatment with mycophenolate mofetil (MMF) and prednisone induced a gradual decline in levels of serum ferritin with a concomitant improvement in renal function and reduction of proteinuria. Serum ferritin may be a useful marker of the response to treatment with MMF in renal lupus.