The silent catecholamine: a rapidly evolving, exclusively dopamine-secreting pheochromocytoma in a 22-year-old

Abstract

Abstract Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors, typically secreting norepinephrine and/or epinephrine. A distinct and uncommon variant is the dopamine-secreting PPGL, often presenting asymptomatically, relatively large, and frequently extra-adrenal. Dopamine-excess may independently indicate a higher malignancy risk. We report the case of a 22-year-old man with an incidentally discovered right adrenal lesion. Biochemical evaluation revealed markedly elevated urinary dopamine and 3-methoxytyramine (3MT). Imaging showed a lipid-poor adrenal mass with minimal [18F]-fluorodeoxyglucose (FDG) avidity. Six months later, the lesion had significantly grown and increased in density, with further elevation of dopamine metabolites. The patient underwent robotic-assisted adrenalectomy following preoperative preparation with oral calcium channel blockers (CCB). Surgery was uneventful, and postoperative catecholamine levels normalized. Histopathology confirmed a pheochromocytoma without features of malignancy. This case highlights the importance of age-specific management in individuals under 40 years, even when the lesion presents benign at first. Noncontrast computed tomography (CT) remains the initial imaging modality of choice. Standard treatment consists of surgical resection. In case of dopamine excess in PPGL, CCB, rather than α-blockers, may be recommended for hemodynamic management.