Analysis of clinicopathological and immunohistochemical features of pheochromocytoma/paraganglioma.

This study aimed to analyze the expression of three immune markers, succinate dehydrogenase (SDHB), S-100, and alpha thalassemia retardation syndrome X-linked (ATRX), in pheochromocytoma and paraganglioma (PPGL) tumor tissues and to evaluate their correlation with histopathological parameters to predict the recurrence risk in PPGLs. A retrospective analysis was conducted using a cohort of 173 patients with PPGLs with definite pathological diagnoses and complete follow-up data. The expression of SDHB, S-100, and ATRX in the tumor tissues was detected using the EnVision immunohistochemical method. Histological grading of PPGLs was performed using the Compound Adrenal Pheochromocytoma and Paraganglioma Grading System (COPPS), and the correlation between the expression of the three immune markers and metastasis or recurrence of PPGLs was analyzed. Among 173 patients with PPGLs, 57 (32.9 %) had metastasis or recurrence. Of these 57 patients, 57.9 % (33/57) had tumors in the retroperitoneum. In 83 % (53/57) of the cases, the maximum diameter of the tumors was ≥5 cm. Vascular invasion was observed in 46 patients (80.7 %). SDHB, ATRX, and S-100 were negatively stained in 33 (57.9 %), 40(70.2 %), and 43(75.4 %) PPGL patients with metastasis or recurrence, respectively, which was significantly higher than that in those without metastasis or recurrence. These differences were statistically significant (P < 0.001). Multivariate analysis showed that tumor diameter ≥ 5 cm, negative ATRX and SDHB expressions, and vascular invasion were independent risk factors for tumor metastasis and recurrence. SDHB, ATRX and S-100 can be used as immunohistochemical indicators to predict the metastatic risk of PPGLs.