Pediatric B Cell Acute Lymphoblastic Leukemia presenting with Paraneoplastic Acute Disseminated Encephalomyelitis

Acute Disseminated Encephalomyelitis (ADEM) is a monophasic demyelinating disease most often triggered by infection or immunization, though associations with malignancy and stem cell transplant have been described. We described the case of a four-year-old boy with new-onset neurological symptoms associated with ADEM, acute leukemia, and equivocal evidence of Mycoplasma pneumoniae infection. He responded to a short course of antibiotics and chemotherapy for B cell acute lymphoblastic leukemia (B-ALL) that included a prolonged course of high dose steroids with immunosuppressive therapy. This case illustrated a possible association between paraneoplastic ADEM and leukemia in pediatric patients.