Clinical characteristics and outcomes of SDHB-related pheochromocytoma and paraganglioma in children and adolescents.

Objective: Pheochromocytomas/paragangliomas (PHEOs/PGLs) are rare in children with only a few SDHB mutation-related cases. Previous studies on children were conducted in small cohorts. This large set of pediatric patients provides robust data in the evaluation of clinical outcomes.

Methods: Sixty-four pediatric PHEO/PGL patients with SDHB germline mutations were included in the present study. The clinical presentation, disease course, and survival rate were evaluated.

Results: Thirty-eight males and 26 females were diagnosed with PHEO/PGL at a median age of 13 years. The majority of patients displayed norepinephrine hypersecretion and 73.44% initially presented with a solitary tumor. Metastases developed in 70% of patients at the median age of 16 years and were mostly diagnosed first 2 years and in years 12-18 post-diagnosis. The presence of metastases at the time of diagnosis had a strong negative impact on survival in males but not in females. The estimated 5-, 10-, and 20-year survival rates were 100%, 97.14%, and 77.71%, respectively.

Conclusions: The present report has highlighted several important aspects in the management of pediatric patients with SDHB mutations associated-PHEO/PGL. Initial diagnostic evaluation of SDHB mutation carriers should be started at age of 5-6 years with initial work-up focusing on abdominal region. Thorough follow-up is crucial first 2 years post-diagnosis and more frequent follow-ups are needed in years 10-20 post-diagnosis due to the increased risk of metastases. Although this age group developed metastasis as early as 5 years from diagnosis, we have shown that the overall 20-year prognosis and survival are good.