A case of normotensive incidentally discovered adrenal pheochromocytoma

Adrenal incidentaloma is an asymptomatic adrenal mass detected on imaging not performed for suspected adrenal disease.1 In most cases, adrenal incidentalomas are nonfunctioning adrenocortical adenomas, but they may also represent conditions requiring therapeutic intervention, including hormone‐producing adenoma, adrenocortical carcinoma, metastasis, and pheochromocytoma (PC). Pheochromocytomas are rare catecholamine‐producing neuroendocrine tumors that arise from chromaffin cells of the adrenal medulla.2 The typical clinical presentation of PC, which is attributed to the hemodynamic and metabolic actions of the excessive catecholamines secreted by the tumors, includes episodic headache, palpitation, sweating, anxiety, hyperglycemia, and sustained or paroxysmal hypertension. However, some PC patients, especially those with an adrenal incidentaloma, are asymptomatic and have consistently normal blood pressure (BP).3, 4, 5, 6, 7, 8, 9 The frequency of incidentally discovered normotensive PC is increasing owing to the better availability and accessibility of imaging procedures.3, 6 Studies have suggested some differences in the clinical, hormonal, and molecular characteristics between normotensive and hypertensive patients with PC.8, 9 Although the elevated urinary excretion of catecholamines and their metabolites (metanephrines) is a useful biochemical diagnostic tool for typical hypertensive PC,2 it is less sensitive in normotensive patients with PC, regardless of tumor size,8, 9 and normotensive PC often poses a diagnostic challenge. Here, we report a case of a patient with normotensive, incidentally discovered adrenal PC.