A Woman with Fatigue, Memory Changes, and Falls

Brain MRI showed numerous white-matter hyperintensities on fluid-attenuated inversion recovery (FLAIR). The lesions had central T2 hyperintensity with a T2-hypointense rim, along with central T1 hypointensity and T1-hyperintense ring enhancement; some rings of enhancement opened toward the cortex (Figure 1). There was no diffusion restriction. Given ongoing diagnostic uncertainty despite results of a lumbar puncture, a brain biopsy was pursued, with histopathology showing myelin loss amid a CD3+ T-cell infiltrate, consistent with tumefactive multiple sclerosis (MS).