Pheochromocytoma: The Range of Appearances on Ultrasound, CT, MRI, and Functional Imaging

OBJECTIVE: Pheochromocytomas are relatively rare neuroendocrine tumors of the adrenal medulla. Their variable clinical presentation and biologic behavior often make accurate diagnosis challenging. A variable spectrum of imaging appearances--some of which may also mimic other diseases--has been recognized. This article reviews the epidemiology; associations; and clinical, biochemical, pathologic, and multimodality imaging features of pheochromocytomas including diagnostic pearls and pitfalls. CONCLUSION: Pheochromocytomas are often considered the great mimicker of other adrenal tumors. Because of their varied clinical, imaging, and pathologic appearances, accurate diagnosis can be challenging. The various imaging appearances on ultrasound, CT, MRI, and functional imaging can be complementary and have features that are useful for differentiating pheochromocytoma from other lesions of the adrenal.