Pheochromocytoma in children and adolescents

Alpha-1 Adrenergic Antagonists Sensitize Neuroblastoma to Therapeutic Differentiation

Neuroblastoma (NB) is an aggressive childhood tumor, with high-risk cases having a 5-year overall survival probability of approximately 50%. The multimodal therapeutic approach for NB includes treatment with the retinoid isotretinoin (13-cis retinoic acid; 13cRA), which is used in the post-consolidation phase as an antiproliferation and prodifferentiation agent to minimize residual disease and prevent relapse. Through small-molecule screening, we identified isorhamnetin (ISR) as a synergistic compound with 13cRA in inhibiting up to 80% of NB cell viability. The synergistic effect was accompanied by a marked increase in the expression of the adrenergic receptor α1B (ADRA1B) gene. Genetic knockout of ADRA1B or its specific blockade using α1/α1B adrenergic antagonists led to selective sensitization of MYCN-amplified NB cells to cell viability reduction and neural differentiation induced by 13cRA, thus mimicking ISR activity. Administration of doxazosin, a safe α1-antagonist used in pediatric patients, in combination with 13cRA in NB xenografted mice exerted marked control of tumor growth, whereas each drug alone was ineffective. Overall, this study identified the α1B adrenergic receptor as a pharmacologic target in NB, supporting the evaluation of adding α1-antagonists to the post-consolidation therapy of NB to more efficiently control residual disease.

SIGNIFICANCE

Targeting α-adrenergic receptors synergizes with isotretinoin to suppress growth and to promote differentiation of neuroblastoma, revealing a combinatorial approach for more effective management of the disease and prevention of relapse.

Reversible cerebral vasoconstriction syndrome (RCVS): an interesting case report

Background

Reversible Cerebral Vasoconstriction Syndrome is a condition of transient cerebral vascular spasms, which usually presents with recurrent thunderclap headaches and recovers within 3 months. Several probable triggers and underlying factors, such as sex hormones, vasoactive drugs, head trauma or surgery, and tumors, have been implicated.

Case presentation

In this paper, we present a 53-year-old woman with thunderclap headaches and normal lab tests who was radio-clinically diagnosed with reversible cerebral vasoconstriction syndrome and treated accordingly. Then, she experienced the recurrence of RCVS after about 2 years and headaches after 1 year in association with high blood pressure, high blood sugar, hypothyroidism, hyperlipidemia, and a urine metanephrine level of 5 times higher than the normal limit, suggesting a diagnosis of pheochromocytoma. After confirmation of the diagnosis with further imaging studies, surgical removal of the tumor resolved all the signs and symptoms.

Conclusion

Often underdiagnosed, pheochromocytoma could be an important condition associated with RCVS. It is important for clinicians to bear this diagnosis in mind while dealing with similar cases of recurrent thunderclap headaches.

Pheochromocytoma and Paraganglioma in Children and Adolescents: Experience of the French Society of Pediatric Oncology (SFCE)

Purpose

The purpose of this work is to assess the clinical outcome of pediatric patients diagnosed with pheochromocytoma and paraganglioma (PPGL) detected in France since 2000.

Methods

A retrospective multicenter study was conducted that included all patients younger than 18 years with PPGL diagnosed in France between 2000 and 2016. Patients were identified from 4 different sources: the National Registry of Childhood Solid Tumors, the French Pediatric Rare Tumors Database, the French registry of succinate dehydrogenase (SDH)-related hereditary paraganglioma, and the nationwide TenGen network.

Results

Among 113 eligible patients, 81 children with available data were enrolled (41 with adrenal and 40 with extra-adrenal PPGL). At diagnosis, 11 had synchronous metastases. After a median follow-up of 53 months, 27 patients experienced a new event (n = 7 second PPGL, n = 1 second paraganglioma [PGL], n = 8 local recurrences, n = 10 metastatic relapses, n = 1 new tumor) and 2 patients died of their disease. The 3- and 10-year event-free survival rates were 80% (71%-90%) and 39% (20%-57%),respectively, whereas the overall survival rate was 97% (93%-100%)at 3 and 10 years. A germline mutation in one PPGL-susceptibility gene was identified in 53 of the 68 (77%) patients who underwent genetic testing (SDHB [n = 25], VHL [n = 21], RET [n = 2], HIF2A [n = 2], SDHC [n = 1], SDHD [n = 1], NF1 [n = 1]). Incomplete resection and synchronous metastases were associated with higher risk of events (P = .011, P = .004), but presence of a germline mutation was not (P = .11).

Conclusions

Most pediatric PPGLs are associated with germline mutations and require specific follow-up because of the high risk of tumor recurrence.

Characteristics of Pediatric Pheochromocytoma/paraganglioma

The "rule of 10" used to describe pheochromocytoma/paragangliomas (PCC/PGLs) has been challenged. However, recent studies suggested that pediatric PCC/PGLs may follow a pattern. Hence, we reviewed the available literature to verify the same. We searched PubMed, Scopus, ProQuest, and Google Scholar for studies describing the genotype and/or phenotype characteristics of pediatric PCC/PGL cohorts published after 2000 in English language and those with sample size more than 35 were included in this review. Pediatric PCC/PGLs were malignant in 10%, synchronous bilateral in 20%, extra-adrenal in 30%, among which, 30% were extra-abdominal and familial in 40%. PCC/PGL diagnosed during pediatric age recurs in 50% by 30 years of follow-up and 60% cases occur in boys. Seventy percent of children with PCC/PGL are likely to have sustained hypertension. Germline mutations could be identified in 80% of children with PCC/PGL and 90% are secretory. The review concludes that pediatric PCC/PGLs follow a pattern, which we call "10%-90% rule." This new rule will help easily remember the characteristics of pediatric PCC/PGLs.

Genotype-Phenotype Correlation in Indian Patients with MEN2-Associated Pheochromocytoma and Comparison of Clinico-Pathological Attributes with Apparently Sporadic Adrenal Pheochromocytoma

INTRODUCTION

Pheochromocytoma (PCC) manifests in up to 50% of MEN2 patients. We correlated the clinico-pathological features of MEN2-associated PCC (MEN-PCC) with RET mutations and compared them with non-MEN adrenal-PCCs.

METHODS

In this retrospective single institution study on a large PCC database (n = 208, 1997-2014) 24 MEN-PCC patients with known RET mutations were reviewed. Excluding 7 with incomplete data, the study cohort of 17 MEN-PCC patients from 11 kindreds (M:F::7:10) was identified. Clinical, biochemical, pathological attributes, and outcomes in the MEN-PCC group were correlated with the genotype, and further compared with non-MEN, apparently sporadic adrenal-PCCs (n = 132, excluding 37 extra-adrenal and 15 VHL/NF1/SDH-associated PCC).

RESULTS

Components of MEN2 encountered included MTC in 13(76.5%), Marfanoid habitus in 2, and PHPT, cutaneous lichen amyloidosis and mucosal neuromas in 1 patient each. In 11(64.7%), PCC was the first detected MEN2 component (Symptomatic:8, Incidentaloma:3). Four (23.5%) were normotensive; 8(47.1%) had bilateral PCC (7 synchronous, 1 metachronous). Surgery for PCC included laparoscopic adrenalectomy in 12; and cortical-sparing adrenalectomy in 2 of 8 bilateral PCC patients. Mean MEN-PCC tumor size was 6.9 ± 3.9 cm, and 6(35%) had additional adrenal medullary hyperplasia. Four different genotypes were encountered, commonest involving codon 634, others being 804 and 918. Mean age in MEN-PCC (27.7 ± 12.2 years) was lower than non-MEN PCC (39.4 ± 15.7, p = 0.018). Proportion of pediatric patients (35.3% in MEN-PCC vs. 12.9% in non-MEN-PCC, p = 0.007), bilateral tumors (47.1% in MEN-PCC, 4.5% in non-MEN-PCC, p < 0.001), and adrenal medullary hyperplasia (35.2% in MEN-PCC, 0.7% in non-MEN-PCC, p < 0.001) were different. Median 24-hour urinary metanephrines was significantly higher in index MEN-PCC patients, than non-MEN-PCC (634 vs. 214 mcg/24 h, p value = 0.006), but was non-significantly higher in non-index MEN-PCC patients. Mean tumor sizes were comparable in the two groups. None of MEN-PCC patients had malignant PCC, compared to 7(5.3%) in non-MEN-PCC.

CONCLUSIONS

In this cohort of MEN-PCC from India, the commonest causative RET mutations for MEN-PCC involved codon 634. MEN-PCC patients were younger, and more frequently had bilateral PCC than non-MEN disease. MEN-PCC patients in India are diagnosed with large tumors and extremely high catecholamine/metanephrine levels.

Pediatric patients with pheochromocytoma: Experience of a tertiary health center

BACKGROUND

The aim of this retrospective study was to investigate pheochromocytoma (pheo), which is a rare endocrine tumor in the pediatric population.

METHODS

The medical records of five children with pheo were studied. The age, gender, clinical presentation, family history, physical findings, coexisting pathology, laboratory evaluation, surgical treatment, and postoperative course were investigated.

RESULTS

The patients were four girls and one boy with a mean age of 13.2 years (range, 9.57-15.95 years). None of the patients had paroxysmal hypertension and one had normal blood pressure. No malign pheo was identified. Mean height and weight standard deviation scores (SDS), body mass index (BMI), and BMI SDS were -0.24, 0.04, 20.9 kg/m(2), and 0.20 at the time of diagnosis, and 0.03, 0.43, 23.8 kg/m(2) and 0.49 1 year after operation, respectively. BMI increased significantly after operation. Three patients had normal epinephrine and metanephrine, but elevated norepinephrine and normetanephrine on 24 h urine. Vanillylmandelic acid on 24 h urine sample was elevated in all patients. Ultrasonography failed to visualize tumors in two patients with bilateral pheo. One patient had postoperative severe hypotension. Insulin resistance associated with severe acanthosis nigricans observed in one patient regressed postoperatively.

CONCLUSIONS

Pheo in children may present with different symptoms and findings. Decreased catecholamine in the postoperative period may lead to weight gain.

Pheochromocytoma management, outcomes and the role of cortical preservation

OBJECTIVES

To evaluate the management and outcome of children with pheochromocytoma and determine the role of cortex preservation in cases of bilateral disease.

METHODS

Retrospective review of children, below 12 y of age, with pheochromocytoma managed between November 2003 and December 2012 was done.

RESULTS

Twelve patients, nine boys and three girls with median age 9 y were enrolled. Eleven (92 %) had adrenal tumors and in one it was extra-adrenal. Five (42 %) had bilateral disease. Ten presented with hypertension, one with headache and one with abdominal pain and fever. All were stabilized pre-operatively with alpha and beta blockers and volume expansion. Six children with unilateral disease underwent total adrenalectomy. Out of five with bilateral disease, one child underwent bilateral total adrenalectomy and was later started on hormone replacement. Remaining four underwent total adrenalectomy on one side and partial on the other side. Post-operatively all became symptom free and normotensive and were off medications within 1 mo. Two children developed recurrence 1 mo post-operatively, one with an initial unilateral pheochromocytoma and one with paraganglionoma. At the last follow up, 10 out of 12(83 %) were disease free while two with recurrence are still awaiting surgery.

CONCLUSIONS

Surgical resection of pheochromocytoma is effective treatment to achieve cure and prolong survival. Cortex preservation should be done in bilateral disease as risk of recurrence in such cases seems to be of lesser significance as compared to the morbidity and mortality of adrenal insufficiency and consequent lifelong hormone replacement.

Anti-hypertensive treatment in pheochromocytoma and paraganglioma: current management and therapeutic features

Pheochromocytoma (PH) and paraganglioma (PG) are neuroendocrine neoplasms arising from chromaffin cells of the adrenal medulla and the sympathetic ganglia, respectively. Although are unusual cause of hypertension (HT) accounting for at most 0.1-0.2 % of cases, they may lead to severe and potentially lethal hypertensive crisis due to the effects of the released catecholamines. However, both PH and PG may be asymptomatic as ~30 % of subjects are normotensive or have orthostatic hypotension and in these cases the 24 h ambulatory blood pressure (BP) monitoring is an important toll to diagnose and treat HT. HT treatment may be difficult when PH or PG occurs in pregnancy or in the elderly subjects and in these cases a multidisciplinary team is required. When surgical excision is mandatory the perioperative management requires the administration of selective α1-adrenergic blocking agents (i.e., doxazosin, prazosin or terazosin) followed by a β-adrenergic blockade (i.e., propranolol, atenolol). This latter should never be started first because blockade of vasodilatory peripheral β-adrenergic receptors with unopposed α-adrenergic receptor stimulation can lead to a further elevation of BP. Although labetalol is traditionally considered the ideal agent due to its α- and β-adrenergic antagonism, experimental studies do not support its use in this clinical setting. As second regimen, the administration of vasodilators as calcium channel blockers (i.e., nicardipine, nifedipine) may be required to control BP. Oral and sublingual short-acting nifedipine are potentially dangerous in patients with hypertensive emergencies and are not recommend. The latest evidences into the diagnosis and treatment of hypertensive crisis due to PH and PG are reviewed here.

Metastatic paraganglioma

Paragangliomas (PGLs) are chromaffin cell tumors arising from ganglia; when arising in the adrenal gland they are called pheochromocytomas. In recent years the opinion that metastatic disease is rare in PGL had to be revised, particularly in patients presenting with extra-adrenal PGL, with PGLs exceeding 5 cm in diameter, and/or those carrying an SDHB germline mutation. Metastases are expected to be present at the time of diagnosis in more than 10% of these patients. Measurement of plasma and urinary metanephrine levels is well established in diagnosing PGL. Recently, a dopaminergic phenotype (excess dopamine or methoxytyramine) was recognized as a good indicator of metastatic disease. Vast progress in targeted positron emission tomography (PET) imaging (eg, (18)F-FDA, (18)F-FDOPA, (18)F-FDG) now allows for reliable early detection of metastatic disease. However, once metastases are present, treatment options are limited. Survival of patients with metastatic PGL is variable, and frequently short. Here we review recent advances involving findings about the genetic background, the molecular pathogenesis, new diagnostic indicators, pathologic markers, and emerging treatment options for metastatic PGL.