Objective: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors that are associated with cancer predisposition syndromes in up to 80% of affected children. PPGLs can be divided into molecularly defined groups with comparable pathogenesis and biology: (1) pseudohypoxic, (2) kinase signaling, and (3) Wnt-altered.
Methods: We report the data of children and adolescents diagnosed with PPGL who have been registered with the German GPOH-MET registry since 1997.
Results: By December 2019, a total of 88 patients with PPGL were reported. Pheochromocytoma occurred in 56%, paraganglioma in 35%, and synchronous PPGLs in 9.1%. A total of 16% of patients presented with lymph node (5.7%) and distant metastases (10%). Median follow-up was 4.2 years (range 0-17.1). Overall and disease-free survival (DFS) were 98.6% and 54.0%, respectively. Local relapses, metastases, and subsequent PPGLs occurred in 11%, 4.5%, and 15% of patients. Germline mutations were detected in 83% of patients (51% in VHL, 21% in SDHB, 7.8% in SDHD, and one patient each in RET and NF1). One patient was diagnosed with Pacak-Zhuang syndrome. A total of 96% of patients presented with PPGL of the pseudohypoxic subgroup (34% TCA cycle-related, 66% VHL/EPAS1-related). In multivariate analyses, extent of tumor resection was a significant prognostic factor for DFS.
Conclusions: Most pediatric PPGLs belong to the pseudohypoxia subgroup, which is associated with a high risk of subsequent PPGL events and metastatic disease. Comprehensive molecular profiling of children and adolescents with newly diagnosed PPGLs will open new avenues for personalized diagnosis, treatment, and surveillance.
Keywords: children; germline mutations; paraganglioma; pheochromocytoma; pseudohypoxic.
© 2021 The Authors. Pediatric Blood & Cancer published by Wiley Periodicals LLC.