Patients want to know whether pheochromocytoma is cancerous and the answer is generally not rarely, however, pheochromocytomas can be cancerous and spread around the body. This occurs about 10% of the time. So not the majority at all. What's important to know is that this can occur many years after the original pheochromocytoma was diagnosed. And that's why long-term followup with your doctor after treatment of a pheochromocytoma, perhaps with surgical removal, for example, is important.