Comparison of clinical and imaging features in succinate dehydrogenase-positive versus sporadic paragangliomas

Background: Limited data exist concerning the clinical and imaging features that distinguish sporadic from familial paragangliomas (PGLs). Methods: Clinical, genetic (succinate dehydrogenase [SDHB] vs no SDHx), and imaging (computed tomography [CT], magnetic resonance imaging, ¹⁸F-fluoro- deoxy-glucose positron emission tomography [ ¹⁸F-FDG-PET]) features obtained during a decade in 124 PGL patients were studied. Data were analyzed by Fisher's exact test or Wilcoxon rank-sum test. Results: Mean age at diagnosis was younger in the SDHB-positive (SDHB+) group compared with the sporadic (no SDHx) group (28 vs 39 years, respectively, P <.001). Rate of supradiaphragmatic neoplasms were greater in the SDHB+ group (16.7 vs 4.7%, P =.11). Metastasis rates were greater in the SDHB+ group (78.9 vs 48.3%, P <.001), as was the existence of metastases or multiple PGLs at presentation (38.5 vs 16.7%, P <.05). Tumor volumes >250 mL were exclusively observed in SDHB+ patients (P <.05). On CT, SDHB+ tumors were more enhanced (P <.05). On ¹⁸F-FDG-PET, SDHB+ tumors' had greater mean standard uptake values (12.3 vs 8.0, P <.05). Conclusion: Clinically young age, large tumor volume, greater rate of metastatic and multifocal PGLs, greater SUV values on ¹⁸F-FDG-PET, and increased CT enhancement are observed in SDHB+ PGLs. These findings may warrant genetic screening. Because SDHB+ patients demonstrate more supradiaphragmatic lesions, whole-body imaging may be of particular value in these patients.