Hypertension in Pheochromocytoma and Paraganglioma: Evaluation and Management in Pediatric Patients

Rare tumors II: Adrenocortical tumors, neuroendocrine tumors of the appendix, pheochromocytoma and paraganglioma, pancreatoblastoma and solid pseudopapillary tumors of the pancreas

Very rare tumors are usually divided into two groups: One includes tumors that are rare among both children and adults; the other one encompasses tumors that frequently occur in adults but are rarely observed in children. In this review, we focus on adrenocortical tumors, neuroendocrine tumors of the appendix, pheochromocytoma and paraganglioma, pancreatoblastoma and solid pseudopapillary tumors of the pancreas, with special attention to the role of surgery as main curative intervention or as part of the multimodal treatment.

Perioperative Blood Pressure Management Recommendations in Pediatric Pheochromocytoma: A 10-Year Narrative Review

BACKGROUND

Pheochromocytomas and paragangliomas are rare chromaffin cell-derived tumors characterized by catecholamine-secreting activity. Pheochromocytomas account for 1.7% of pediatric hypertension cases. Surgical resection, the definitive pheochromocytoma treatment, carries risks of hemodynamic instability and cardiovascular complications. Nevertheless, mortality rates decreased significantly in the latter half of the 20th century due to effective perioperative blood pressure (BP) management. The literature on BP management tailored to pediatric pheochromocytoma is limited, while the sustained hypertension rate in this population is high (up to 90%) and related to a high risk of intraoperative complications. In this narrative review, we provide up-to-date recommendations regarding BP management to minimize perioperative comorbidities in children with pheochromocytoma.

SUMMARY

Antihypertensive agents, primarily alpha (α)-blockers, should be promptly administered for suspected pheochromocytoma. Beta (β)-blockers may be introduced thereafter to counteract reflex tachycardia. The patient must be salt- and water-replete preoperation. Intraoperatively, stable hemodynamics should be ensured during anesthesia and surgery, and short-acting intravenous medications and resuscitation fluid should be supplied. Postoperatively, patients should be admitted to the pediatric intensive care unit for close monitoring for at least 24-48 h. Genetic testing is recommended for all pheochromocytoma patients. Identifying underlying mutations, like in succinate dehydrogenase subunit B, which is linked to a higher risk of multifocality and metastasis, is imperative for tailoring treatment strategies and prognostication.

KEY MESSAGES

Achieving optimal outcomes in pediatric pheochromocytoma relies on preoperative BP optimization with appropriate antihypertensive agents, intraoperative hemodynamic stability, and postoperative routine long-term follow-up to monitor for complications, recurrence, and metastasis. Future research should prioritize well-designed prospective multicenter studies with adequate sample sizes and, where feasible, randomized controlled trials with standardized protocols and appropriate endpoints. These studies should focus on the efficacy and safety of preoperative nonselective versus selective α-blockers, whether as monotherapy or combined with other medications (e.g., calcium channel blockers and/or β-blockers), or treatment without preoperative anti-hypertensives.

International consensus statement on the diagnosis and management of phaeochromocytoma and paraganglioma in children and adolescents

Phaeochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumours that arise not only in adulthood but also in childhood and adolescence. Up to 70-80% of childhood PPGL are hereditary, accounting for a higher incidence of metastatic and/or multifocal PPGL in paediatric patients than in adult patients. Key differences in the tumour biology and management, together with rare disease incidence and therapeutic challenges in paediatric compared with adult patients, mandate close expert cross-disciplinary teamwork. Teams should ideally include adult and paediatric endocrinologists, oncologists, cardiologists, surgeons, geneticists, pathologists, radiologists, clinical psychologists and nuclear medicine physicians. Provision of an international Consensus Statement should improve care and outcomes for children and adolescents with these tumours.

Prevention and management of hypertensive crises in children with pheochromocytoma and paraganglioma

Hypertensive crises in pediatric patients are rare conditions. However, determining their precise prevalence is more challenging than in adults due to the heterogeneity in the definition itself. These crises frequently occur without a prior diagnosis of hypertension and may indicate an underlying cause of secondary hypertension, including pheochromocytoma/paraganglioma (PPGL). The mechanisms of hypertensive crises in the pediatric population with PPGL are directly related to different types of catecholamine excess. Noradrenergic tumors typically present with sustained hypertension due to their predominant action on α1-adrenoceptors in the vasculature. Conversely, adrenergic tumors, through epinephrine binding to β2-adrenoceptors in addition to stimulation of α1- and α2-adrenoceptors, more frequently cause paroxysmal hypertension. Furthermore, the biochemical phenotype also reflects the tumor localization and the presence of a genetic mutation. Recent evidence suggests that more than 80% of PPGL in pediatric cases have a hereditary background. PPGL susceptibility mutations are categorized into three clusters; mutations in cluster 1 are more frequently associated with a noradrenergic phenotype, whereas those in cluster 2 are associated with an adrenergic phenotype. Consequently, the treatment of hypertensive crises in pediatric patients with PPGL, reflecting the underlying pathophysiology, requires first-line therapy with alpha-blockers, potentially in combination with beta-blockers only in the case of tachyarrhythmia after adequate alpha-blockade. The route of administration for treatment depends on the context, such as intraoperative or pre-surgical settings, and whether it presents as a hypertensive emergency (elevated blood pressure with acute target organ damage), where intravenous administration of antihypertensive drugs is mandatory. Conversely, in cases of hypertensive urgency, if children can tolerate oral therapy, intravenous administration may initially be avoided. However, managing these cases is complex and requires careful consideration of the selection and timing of therapy administration, particularly in pediatric patients. Therefore, facing these conditions in tertiary care centers through interdisciplinary collaboration is advisable to optimize therapeutic outcomes.

Management of acute severe hypertension in youth: from the philosophical to the practical

PURPOSE OF REVIEW

Acute severe hypertension remains an uncommon but important source of morbidity and mortality in youth. However, there has been very little progress made in our understanding of how to best manage youth with acute severe hypertension to improve patient outcomes.

RECENT FINDINGS

Our understanding of what is acute severe hypertension is undergoing a philosophical change. Management of patients with acute severe hypertension is evolving towards more of a risk and outcomes-based approach.

SUMMARY

We should be intentional when we consider whether a patient has acute severe hypertension and if they are truly at an increased risk for life-threatening target organ injury. We should consider their specific risk factors to best interpret the risks and benefits of how best to treat a patient with acute severe hypertension, rather than relying on traditional approaches and conventional wisdom. We should always ask 'why' when we are pursuing a given management course. Future studies should clearly define the research questions they are investigating to best advance the field to ultimately improve patient outcomes.

Pediatric Metastatic Pheochromocytoma and Paraganglioma: Clinical Presentation and Diagnosis, Genetics, and Therapeutic Approaches

Although pediatric pheochromocytomas and paragangliomas (PPGLs) are rare, they have important differences compared to those in adults. Unfortunately, without timely diagnosis and management, these tumors have a potentially devastating impact on pediatric patients. Pediatric PPGLs are more often extra-adrenal, multifocal/metastatic, and recurrent, likely due to these tumors being more commonly due to a genetic predisposition than in adults. This genetic risk results in disease manifestations at an earlier age giving these tumors time to advance before detection. In spite of these problematic features, advances in the molecular and biochemical characterization of PPGLs have heralded an age of increasingly personalized medicine. An understanding of the genetic basis for an individual patient's tumor provides insight into its natural history and can guide clinicians in management of this challenging disease. In pediatric PPGLs, mutations in genes related to pseudohypoxia are most commonly seen, including the von Hippel-Lindau gene (VHL) and succinate dehydrogenase subunit (SDHx) genes, with the highest risk for metastatic disease associated with variants in SDHB and SDHA. Such pathogenic variants are associated with a noradrenergic biochemical phenotype with resultant sustained catecholamine release and therefore persistent symptoms. This is in contrast to paroxysmal symptoms (e.g., episodic hypertension, palpitations, and diaphoresis/flushing) as seen in the adrenergic, or epinephrine-predominant, biochemical phenotype (due to episodic catecholamine release) that is commonly observed in adults. Additionally, PPGLs in children more often present with signs and symptoms of catecholamine excess. Therefore, children, adolescents, and young adults present differently from older adults (e.g., the prototypical presentation of palpitations, perspiration, and pounding headaches in the setting of an isolated adrenal mass). These presentations are a direct result of genetic determinants and highlight the need for pediatricians to recognize these differences in order to expedite appropriate evaluations, including genetic testing. Identification and familiarity with causative genes inform surveillance and treatment strategies to improve outcomes in pediatric patients with PPGL.