Clinical Focus ›› 2026, Vol. 41 ›› Issue (6): 534-538.doi: 10.3969/j.issn.1004-583X.2026.06.009

Previous Articles     Next Articles

Association between plasma free metanephrines and the SDHB phenotype in pheochromocytoma and paraganglioma

Wang Liyang(), Xiang Dandan, Ding Ran   

  1. Medical Genetics Center, Nanyang Second People's Hospital, Nanyang 473000, China
  • Received:2026-04-08 Online:2026-06-20 Published:2026-07-01
  • Contact: Wang Liyang,Email: wangliy1823@163.com

Abstract:

Objective To investigate the association between plasma free metanephrines (MNs) and the succinate dehydrogenase subunit B (SDHB) phenotype in pheochromocytoma and paraganglioma (PPGL). Methods A total of 190 patients with PPGL treated at our hospital from March 2021 to March 2025 were enrolled as the study group. In addition, 100 healthy individuals who underwent physical examination at the same hospital during the same period and had normal results were selected as the control group. Baseline data were collected for both groups. Plasma metanephrine (MN) and normetanephrine (NMN) levels were measured using high-performance liquid chromatography-tandem mass spectrometry. SDHB protein expression in the study group was detected by immunohistochemical EnVision two-step method. The correlation between MN/NMN levels and the SDHB phenotype (loss/positive) was analyzed, along with their associations with clinicopathological characteristics. Results Plasma MN and NMN levels were significantly higher in the study group than in the control group (P<0.05). Among the 190 patients with PPGL, SDHB loss was observed in 68 cases (35.79%), of which paraganglioma (PGL) accounted for 83.82% (57/68), significantly higher than pheochromocytoma (PCC) (16.18%, 11/68) (P<0.05). The plasma NMN level in the SDHB-loss group was significantly higher than that in the SDHB-positive group ([7.53±1.95] nmol/L vs [5.19±1.26] nmol/L, P<0.05), whereas no statistically significant difference in MN level was found between the two groups (P>0.05). SDHB loss was associated with age, hypertension, tumor location, tumor type, vascular invasion, Ki-67 proliferation index, metastasis, and plasma NMN level (P<0.05). Conclusion Plasma NMN level is closely associated with the SDHB phenotype in PPGL. SDHB loss is more common in PGL, and patients with SDHB loss often have elevated NMN levels. SDHB loss is also significantly associated with adverse clinicopathological features, including age, hypertension, tumor location, tumor type, vascular invasion, Ki-67 proliferation index, and metastasis.

Key words: pheochromocytoma, paraganglioma, free metanephrines, SDHB phenotype, correlation

CLC Number: