Patients with white matter lesions and multiple sclerosis (MS) could develop B-cell-type primary central nervous system lymphoma (PCNSL) after receipt of a first-line disease-modifying therapy (DMT). A recent case report in Clinical and Experimental Neuroimmunology showed diffuse large B-cell lymphoma (DLBCL) of PCNSL may rapidly progress following DMT with dimethyl fumarate (DMF) in patients with relapsing and remitting MS (RRMS) and white matter lesions.

The case study was a 56-year-old Japanese man who had asymptomatic white matter lesions of the left frontal lobe on magnetic resonance imaging (MRI) at a medical checkup. On a follow-up appointment on day 46, the patient had no neurologic symptoms or brain changes on MRI. At 74 days from his initial checkup, the patient had right upper limb paralysis and was admitted to the hospital.

Neurologic symptoms improved following administration of immunotherapy. The patient had a relapse of motor paralysis on day 170 and developed vision loss in the right eye. Neurologic symptoms subsequently recovered gradually without intervention. MRI on day 170 detected no white matter changes. The patient was later diagnosed with RRMS and received DMF.

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At 3 months following receipt of DMF, the patient presented with new lesions in the right basal ganglia and insular cortex. While the patient then received 2 cycles of methylprednisolone for 3 days, in addition to 1 cycle of intravenous immunoglobulin for 5 days, the neurologic symptoms and brain lesions rapidly progressed.

Pathological findings of the right basal ganglia lesions on day 301 showed evidence of DLBCL, and the patient ultimately received a diagnosis of B-cell-type PCNSL. He experienced partial improvement of neurologic symptoms after chemotherapy, allowing him to walk with assistance. Aside from the initial white matter lesion, brain lesions had improved by day 460 and the patient was discharged with his caregiver by day 504.

Ultimately, the study authors concluded that “patients with rapidly progressing white matter lesions following DMF administration should be suspected for B-cell type PCNSL and pathologically diagnosed using brain biopsy.”


Kitazaki Y, Ueno A, Maeda K, et al. Primary diffuse large B-cell lymphoma of the central nervous system with rapidly progressing lesions after dimethyl fumarate treatment, showing relapsing and remitting symptoms: A case report. Clin Exp Neuroimmunol. Published online July 4, 2021. doi:10.1111/CEN3.12656

This article originally appeared on Neurology Advisor