Abstract:

Objective To explore the roles of plasma metanephrine (MN) and normetanephrine (NMN) in diagnosis of chromaffin cell tumors. Methods From May 2003 to December 2008, patients with indications for chromaffin cell tumor screening in Ruijin Hospital affiliated to Shanghai Jiaotong University School of Medicine were selected. Plasma NMN and MN levels were detected by high performance liquid chromatogram, and were compared between patients with chromaffin cell tumors and those without. Besides, plasma NMN and MN levels before operation were compared with those after operation in patients with chromaffin cell tumors. Receiver operating characteristic (ROC) curves were employed to determine the sensitivity and specificity of plasma NMN and MN in diagnosis of chromaffin cell tumors. Results Two hundred and fifty-nine patients with chromaffin cell tumors and 4 387 patients without were enrolled. The area under ROC curve of NMN was 0.989±0.005, and that of MN was 0.783±0.019. There were significant differences in NMN and MN levels between patients with chromaffin cell tumors and those without, (2930.56±4166.56) pg/mL vs (70.48±25.07) pg/mL and (585.68±1368.75) pg/mL vs (45.61±42.63) pg/mL, respectively (P=0.00 for both).The sensitivity and specificity were 95.4% and 90.0% respectively for plasma NMN of 130 pg/mL, and those were 51.4% and 90.0% respectively for plasma MN of 83 pg/mL. Besides, there were significant differences between NMN and MN levels before operation and those after operation in 69 patients with chromaffin cell tumors, (3 145.8±3651.86) pg/mL vs (233.1±934.92) pg/mL and (653.7±1053.12) pg/mL vs (47.56±25.82) pg/mL, respectively (P=0.00 for both). Conclusion Plasma NMN and MN levels can be adopted as optimal parameters in screening chromaffin cell tumors, and plasma NMN and MN levels after operation may indicate the outcomes and help to detect early recurrence or metastasis of the tumors.

Key words: pheochromocytoma, paraganglioma, metanephrine, normetanephrine, diagnosis