[Evaluation of urinary metanephrines for the diagnosis of pheochromocytoma].

OBJECTIVE: evaluate the assay of urinary metanephrines in diagnosis of pheochromocytoma (PH) and determine diagnostic cut-off values. METHODS: this is a retrospective study about 87 patients suspected of pheochromocytoma,whose of 24-h urinary fractionated metanephrine was measured. These cases were collected from Internal Medecine Departments (A and B) at Charles Nicolle's Hospital. Two groups of patients were studied: a pheochromocytoma group (n=33) with a histologically-proven pheochromocytoma and a control group of 54 patients. Receiver Operating Characteristic (ROC) curves were used to determine the best sensitivities and specificities. RESULTS: The analysis of biological parameters showed that means and standard deviation of urinary fractionated metanephrines in pheochromocytoma group were significantly higher than those of control group. Sensitivity and specificity of urinary normetanephrine test (95% and 98.1% respectively) were higher than those of urinary metanephrine and 3-methoxytyramine. A correlation between urinary normetanephrine and tumor size of pheochromocytoma was found. CONCLUSION: Urinary fractionated metanephrines is an efficient biochemical test for the diagnosis of pheochromocytoma.