Azacitidine-induced massive pericardial effusion in a child with myelodysplastic syndrome.

Introduction: Pericardial effusions are rare yet potentially fatal conditions in children. Azacitidine is a DNA-hypomethylating agent used in the treatment of myelodysplastic syndrome. Although seldomly described in adults, no cases of azacitidine-induced pericardial effusion have been reported in children.
Case Report: A 7-year-old boy with myelodysplastic syndrome presented with a large pericardial effusion with risk for cardiac tamponade after his first azacitidine cycle.
Management & Outcome: The patient was admitted to a pediatric ICU, antibiotic and steroid therapy were initiated. Pericardiocentesis was done due to hemodynamic instability. Serum and pericardial fluid complementary evaluation excluded infectious and malignant causes. The pericardial effusion did not reappear and additional pleural and ascitic slight effusions responded well to diuretics. Follow-up azacitidine cycles were administered by tapering daily dosages and using adjunctive steroid therapy, with no additional adverse events.
Discussion: We report the first pediatric case of large pericardial effusion secondary to azacitidine therapy in a child with MDS. This adverse reaction has not been described in pediatric patients, in which this therapeutic option has been increasingly used. We seek to raise awareness on the potential life-threatening cardiotoxicity of azacitidine in pediatric patients.