Tumefactive Demyelinating Lesions in Patients with Relapsing Remitting Multiple Sclerosis Treated with Fingolimod

We report a case of a woman with relapsing remitting multiple sclerosis presenting with tumefactive demyelination at disease onset and treated with natalizumab after failure of first-line drugs. Patient was shifted from natalizumab to fingolimod treatment because of progressive multifocal leukoencephalopathy risk. Thirteen months after starting fingolimod treatment she developed a relapse with brain MRI findings of tumefactive demyelinating lesions. We also present a literature review on similar cases discussing a possible role of the drugs in determining brain tumefactive lesions.