Snuff-induced hypertension in pheochromocytoma.

The dipping of snuff provoked paroxysmal hypertension that induced myocardial ischemia in a 69-year-old woman with pheochromocytoma. The diagnosis of her tumor was delayed by a report of a falsely low urine metanephrine level, resulting from interference with the metanephrine assay by meglumine present in the urine because of contrast coronary angiography performed on the day of urine collection.