Pheochromocytoma presenting with QT prolongation and catecholamine-induced myocarditis in a child.

Pheochromocytomas are catecholamine-producing tumors derived from the adrenomedullary chromaffin cells. The presentation is a classic triad of episodic headaches, sweating, and tachycardia. Hypertensive crisis can occur due to profuse catecholamine excess. Unusual manifestations mimicking cardiogenic shock, arrhythmia, and myocarditis have been rarely reported in children. We present a case with uncommon manifestations of pheochromocytoma in a child, including the episodes of exercised-induced presyncope with QT prolongation, and subsequently cardiogenic shock due to fulminant myocarditis. He later developed hypertensive crisis. The adrenal mass on abdominal computed tomography with an increased chromogranin A level and elevated plasma normetanephrine, and the histological study confirmed the diagnosis of pheochromocytoma. Cardiac functions completely recovered after adrenalectomy. Genetic testing was positive for von Hippel-Lindau syndrome. We describe pheochromocytoma crisis presenting with prolonged QT and catecholamine-induced myocarditis. We discuss the clues to assist in the diagnosis of this condition and its appropriate treatment.