A case of demyelinating pseudotumor, considered an acute fulminant variant of multiple sclerosis (MS), occurring in a patient with definite MS is presented. Magnetic resonance imaging (MRI) showed a large, biopsy-proven demyelinating lesion with ring enhancement and mass effect. Treatment resistance to corticosteroids and β-interferons occurred, which prompted our present use of combined corticosteroids/plasmapheresis followed by mitoxantrone.
A 50-year-old Caucasian man presented with acute onset confusion, inappropriate speech, and forgetfulness, as well as depressive symptoms for the preceding 2 years. On neurological examination, disorientation, a right lower facial paresis, and symmetrical hyperreflexia were present, but there was no papilledema or Babinski response probably owing to the acuteness of this process. Axial T1-weighted postgadolinium images (Figure 1) and fluid-attenuated inversion recovery MRI (Figure 2) show a left hemisphere contrast-enhancing ring lesion with massive edema and midline shift, and smaller typical MS lesions in the right hemisphere (and brainstem). Fluorodeoxyglucose F 18 positron emission tomography showed only the ring-enhanced area to be hypermetabolic. On biopsy of the ring-enhanced area, acute and chronic perivascular inflammation with foamy macrophages, thrombotic small vessels without evidence of vasculitis, reactive astrocytosis, and small areas of white matter edema and necrosis were present, which is consistent with demyelinating pseudotumor.1 Cerebrospinal fluid examination revealed 13 cells (mixed polymorphonuclears and lymphocytes), elevated IgG levels, and oligoclonal bands (not present systemically). Test results for other autoimmune and infectious etiologies were negative. Response to prolonged high-dose methylprednisolone and dexamethasone was minimal with multiple secondary complications. Clinical/MRI exacerbations, including 2 with mass effect minimally responsive to corticosteroids and occurring on β interferons, were documented over the next 2 years.
Jaffe SL, Minagar A. Demyelinating Pseudotumor. Arch Neurol. 2005;62(9):1466-1467. doi:10.1001/archneur.62.9.1466