Tumefactive multiple sclerosis.

Tumefactive multiple sclerosis (MS) is a subtype of atypical and rare MS that presents with tumor-like lesions in the central nervous system. The lesions may demonstrate a mass effect, edema, with ring enhancement. They can be mistaken for brain tumors or brain abscesses radiologically and clinically. Here we describe an instructive case of a 55-year-old woman with tumefactive MS who presented with occasional numbness in her right arm and leg, headache, thought confusion, and blurred vision for 2 years.