tumefactive demyelination

We report a case of a 12-year-old male who initially presented with active systemic lupus erythematosus (SLE) with lupus nephritis and secondary macrophage activation syndrome (MAS). He went on to develop left-sided upper motor neuron (UMN) facial palsy secondary to lupus-related tumefactive demyelination. Tumefactive lesions secondary to demyelination are a very rare manifestation in neuropsychiatric SLE. This child responded to aggressive immunosuppression with steroids and cyclophosphamide.