Paroxysmal Hypertension in Congenital Hypothyroidism: An Unusual Case of Pheochromocytoma.

Pheochromocytomas are rare tumors arising from the chromaffin cells of the adrenal medulla that result in the secretion of excessive catecholamines. They are an uncommon cause of hypertension in the pediatric population. We present a case of a six-year-old male with hypertension, rapid weight loss, palpitations, excessive sweating, and vomiting. Their previous medical history was significant for congenital hypothyroidism, and upon the emergence of his symptoms, his levothyroxine dosing was reduced to half. Presenting symptoms and initial history were suspicious for thyroid-related disease; however, imaging showed a complex right adrenal mass in the setting of elevated plasma catecholamine levels. A diagnosis of pheochromocytoma was made, and a right adrenalectomy was performed. The patient tolerated the procedure well, with complete resolution of symptoms. Three years later, his symptoms re-emerged and were concerning for tumor recurrence. This case highlights the diagnosis of this rare cause of pediatric hypertension and the importance of remaining vigilant against anchoring bias.