[A pediatric case of multiple sclerosis mimicking malignant brain tumor].

We report a pediatric case of multiple sclerosis mimicking malignant brain tumor. A 11-year-old male presented with high fever, vomiting and partial convulsion of left lower extremity followed by left visual impairment. Magnetic resonance imaging (MRI) revealed a mass lesion in the right frontal lobe with significant peripheral edema. Incomplete ring-like enhancement by gadolinium administration was also noted. Open biopsy of the lesion was undertaken that provided pathological confirmation of demyelinating changes. Luxol fast blue stain and Bodian stain demonstrated extensive myelin loss and good preservation of axons. The patient was given intravenous high-dose methyl-prednisolone and sequential oral low-dose prednisone, which improved his neurological status progressively. The lesion was dramatically decreased in size and finally disappeared. Although many tumor-like demyelinating lesions were reported previously, pediatric cases of multiple sclerosis mimicking malignant brain tumor are extremely rare. Pathological examinations including Luxol fast blue stain and Bodian stain are essential for exact diagnosis.