Successful Treatment of Syndrome of Inappropriate Antidiuretic Hormone Secretion Associated with Neuro-Sweet Disease in Myelodysplastic Syndrome

Sweet disease may occur in several organs, and central nervous system involvement, known as Neuro-Sweet disease (NSD), is rare. The clinical features of NSD include recurrent encephalomeningitis accompanied by fever and erythematous plaques; systemic corticosteroid therapy is highly effective. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is an important electrolyte abnormality because it can be life-threatening. We describe the first case of SIADH and NSD associated with low-risk myelodysplastic syndrome that was successfully treated with corticosteroids and cyclosporine. The patient has remained stable for 1 year without any recurrence.