Is It Enough to Diagnose Pheochromocytoma by Measuring Urine Metanephrines Levels?

This study aimed to evaluate the diagnostic value of plasma and urinary metanephrines and determine their sensitivity, specificity, and correlation among patients with adrenal lesions, which required a multidisciplinary approach because of size, functional state, or malign appearance. This retrospective study of 152 patients with adrenal lesions was conducted at the Outpatient Clinics of Ankara Bilkent City Hospital at the Department of Endocrinology and Metabolism Diseases between August 2019 and February 2022. These patients were discussed at the Endocrinology and Surgery multidisciplinary council because of their adrenal lesions. Among them, 94 patients underwent adrenal surgery. Thirty patients with histologically proven pheochromocytoma, 36 with cortical nodular hyperplasia, four cases of adrenocortical carcinoma and 24 cases with angiomyolipoma were detected. According to the analysis, the most sensitive test in diagnosing pheochromocytoma was urinary fractionated metanephrine (90%), followed by plasma free metanephrines at 84 %. Conversely, the most specific test was plasma free normetanephrine (91.4%). A statistically significant correlation exists between plasma and urinary metanephrine; plasma normetanephrine levels were also significantly correlated with urine normetanephrine. These findings indicate that plasma and urine metanephrines are sensitive for detecting pheochromocytoma and can be used interchangeably.