Incidental Discovery of Malignant Pheochromocytoma During Preoperative Coronary Artery Bypass Surgery (CABG) Workup.

Pheochromocytomas are catecholamine-secreting neuroendocrine tumors that occur in less than 0.2% of patients presenting with hypertension. Of these, approximately 10% are found to have malignant potential, thus further demonstrating their rarity. In patients with uncontrolled hypertension, a pheochromocytoma should be included in the differential diagnosis.  A 54-year-old male with a past medical history of coronary artery disease (CAD) and hypertension presented to the emergency department with chest pain. On workup, there was concern for acute coronary syndrome, and he was taken to the cardiac catheterization suite. He was found to have multi-vessel CAD, and the decision was made for a coronary artery bypass surgery (CABG). Prior to the procedure, he was found to have a left adrenal mass, which was ultimately found to be a malignant pheochromocytoma.  Pheochromocytomas are rare neuroendocrine tumors composed of chromaffin cells, which are responsible for the secretion of catecholamines. These tumors occur in less than 0.2% of patients with hypertension and can be benign or malignant, with malignancy occurring in 10% of cases. According to the World Health Organization (WHO), malignant pheochromocytomas can only be defined with the presence of regional invasion or metastasis in a non-chromaffin site.  In conclusion, despite the rarity of pheochromocytomas, it is important to keep these tumors in the differential diagnosis, especially when considering a patient with refractory hypertension. Any incidentaloma with appropriate clinical history, such as uncontrolled hypertension, should raise the suspicion of pheochromocytoma.