Pheochromocytoma

To the Editor: I read with avid interest the IM Board Review by Pagán et al on a man with pheochromocytoma.¹ The article stated that the classic triad is headache, hypertension, and hyperglycemia. I found this to be incorrect. And Harrison’s Principles of Internal Medicine² states that the classic triad is palpitations, headaches, and profuse sweating. I hope you will clarify this in the interest of the readers as it is a board review article.