Unrecognized mediastinal tumor causing sudden tracheal obstruction and out-of-hospital cardiac arrest.

We report a case of a 13-year-old boy with a presumed neck cyst who developed sudden tracheal obstruction and out-of-hospital cardiac arrest. Cardiorespiratory collapse occurred due to an improperly diagnosed mediastinal tumor. This report serves to alert Emergency Physicians and emergency medical services personnel of the rare and rapidly progressive nature of respiratory compromise caused by a mediastinal tumor, which may have lethal consequences if not recognized and treated promptly.