Critical airway obstruction, superior vena cava syndrome, and spontaneous cardiac arrest in a child with acute leukemia.

We report the unusual presentation of a previously healthy girl with sudden cardiopulmonary arrest caused by acute lymphoblastic leukemia and mediastinal involvement leading to acute tracheal and airway obstruction. Despite active resuscitation and mechanical ventilation, she developed severe cerebral edema as a result of cerebral asphyxia. She also had facial edema caused by superior vena cava obstruction, a high peripheral white cell count with blast differentials, and renal failure. Because of severe asphyxia leading to brain death and renal failure, chemotherapy was withheld. Her white cell count spontaneously reverted to reference range without chemotherapy. This report serves to alert clinicians of the oncological emergency of "superior mediastinal syndrome" causing airway and superior vena cava obstruction leading to death in this potentially curable disease.