Teaching NeuroImage: Spontaneously Resolving Ring-Enhancing Lesions Due to Immunodeficiency-Associated CNS Lymphoma

A 57-year-old woman with systemic lupus erythematosus on mycophenolate mofetil (MMF) presented after a tonic-clonic seizure. Brain MRI revealed 7 gadolinium-enhancing lesions (Figure 1A). CSF protein, glucose, and cell count were normal, and microbiological tests for opportunist agents were negative, raising our suspicion for lymphoma. Prebiopsy MRI showed spontaneous improvement of most lesions, with increased size of the largest lesion (Figure 1B). Brain biopsy (Figure 2) was consistent with immunodeficiency-associated CNS lymphoma. MMF treatment cessation led to substantial improvement after 5 months (Figure 1C).