Pediatric pheochromocytoma and paraganglioma: an update.
[von hippel-lindau disease]
Pheochromocytomas and paragangliomas (PHEO/PGL) are neuroendocrine tumors that arise from sympathetic and parasympathetic paraganglia. Although well described in the adult population, diagnosis and treatment of these exceptionally rare neoplasms remains poorly characterized in children. This article reviews recent advances in clinical presentation, genetics, biochemistry, imaging and treatment of children with benign or malignant PHEO/PGL. Compared to adults, pediatric PHEO/PGL are more frequently familial, bilateral, multifocal and malignant. Approximately 50% of pediatric PHEO/PGL are associated with a mutation of one of the 12 known susceptibility genes. Von Hippel-Lindau disease, type 1 neurofibromatosis, type 2 multiple endocrine neoplasia and familial PGL syndrome are hereditary tumor syndromes associated with an increased risk of developing such diseases. Clinical presentation includes symptoms related to catecholamine hypersecretion and/or tumor mass effect. Plasma and/or urine metanephrine dosages are recommended as first-line diagnostic biochemical tests. Magnetic resonance imaging is useful as initial radiological approach. Most pediatric PHEO/PGLs are benign. Surgical resection, with appropriate perioperative management of catecholamine-related symptoms, remains the treatment of choice. In case of metastatic disease, surgical removal of metastases when possible and I-131-MIBG radiotherapy provide limited results whereas chemotherapy is reserved for more advanced stages.