How To Locate A Pheochromocytoma Causing Headaches And Spike In BP? Can It Lead To Stroke?

My mother was diagnosed with a Pheochromocytoma but they cannot find where it is located, they have done multiple scans, they say sometimes they can hide in the tissues of your body. She has all the symtoms including headaches, quick rising spikes of her blood pressure and she has problems breathing at times. They say they know this is what it is because of the high levels of catecholamines in her urine, I'm worried she could have a stroke if they don't find it in time do you have any suggestions??????