Childhood phaeochromocytoma and paraganglioma: 100% incidence of genetic mutations and 100% survival

Operative management and outcome in children with pheochromocytoma

OBJECTIVE

This study aimed to evaluate management and prognosis in children with pheochromocytoma who were treated at an Egyptian tertiary center.

METHODS

The authors conducted an 8-year retrospective analysis for 17 patients who were presented from January 2013 to January 2021. Clinical criteria, operative details, and follow-up data were assessed. Overall (OS) and event-free survival (EFS) were estimated by the Kaplan-Meier method. An event was assigned with the occurrence of recurrence or metachronous disease, or death.

RESULTS

Median age at diagnosis was 14 years (range: 6-17.5 years). Ten patients (58.8%) were males and seven (41.2%) were females. Hypertension-related symptoms were the main presentations in 15 patients (88%). None of the included children underwent genetic testing. Sixteen patients (94%) had unilateral tumors (right side: 12), whereas only one was presented with bilateral masses. The median tumor size was 7 cm (range: 4-9 cm). Metastatic workup did not reveal any metastatic lesions. All patients underwent open adrenalectomy, and clinical manifestations were completely resolved after surgery. Adjuvant therapy was not administered to any patient. There were no deaths or relapses at a median follow-up time of 40 months, whilst two children had metachronous disease after primary resection. Both were managed by adrenal-sparing surgery, and they achieved a second complete remission thereafter. Five-year OS and EFS were 100% and 88%, respectively.

CONCLUSIONS

Complete surgical resection achieves excellent clinical and survival outcomes for pheochromocytoma in children. Meticulous, long-term follow-up is imperative for early detection of metachronous disease to facilitate adrenal-sparing surgery. Genetic assessment for patients and their families is essential; however, it was not available at our institution.

Clinical Practice Guidance: Surveillance for phaeochromocytoma and paraganglioma in paediatric succinate dehydrogenase gene mutation carriers

The succinate dehydrogenase (SDH) enzyme complex functions as a key enzyme coupling the oxidation of succinate to fumarate in the citric acid cycle. Inactivation of this enzyme complex results in the cellular accumulation of the oncometabolite succinate, which is postulated to be a key driver in tumorigenesis. Succinate accumulation inhibits 2-oxoglutarate-dependent dioxygenases, including DNA and histone demethylase enzymes and hypoxic gene response regulators. Biallelic inactivation (typically resulting from one inherited and one somatic event) at one of the four genes encoding the SDH complex (SDHA/B/C/D) is the most common cause for SDH deficient (dSDH) tumours. Germline mutations in the SDHx genes predispose to a spectrum of tumours including phaeochromocytoma and paraganglioma (PPGL), wild type gastrointestinal stromal tumours (wtGIST) and, less commonly, renal cell carcinoma and pituitary tumours. Furthermore, mutations in the SDHx genes, particularly SDHB, predispose to a higher risk of malignant PPGL, which is associated with a 5-year mortality of 50%. There is general agreement that biochemical and imaging surveillance should be offered to asymptomatic carriers of SDHx gene mutations in the expectation that this will reduce the morbidity and mortality associated with dSDH tumours. However, there is no consensus on when and how surveillance should be performed in children and young adults. Here, we address the question: "What age should clinical, biochemical and radiological surveillance for PPGL be initiated in paediatric SDHx mutation carriers?".

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 paediatric pheochromocytoma and paraganglioma: a single centre experience from India

BACKGROUND

Data on genotype-phenotype correlation in children is limited. Hence, we studied the prevalence of germline mutations and genotype-phenotype correlation in children with pheochromocytoma (PCC)/paraganglioma (PGL) and compared it with adult PCC/PGL cohort.

METHODS

A total of 121 consecutive, unrelated, index PCC/PGL patients underwent genetic testing for five PCC/PGL susceptibility genes (RET, VHL, SDHB, SDHD and SDHC) and were evaluated for clinical diagnosis of neurofibromatosis type1 (NF1).

RESULTS

Thirty patients (12 boys, 18 girls) presented at ≤20 years of age (mean age of 15.9±3.8 years). Children were more frequently symptomatic and more frequently had bilateral PCC than adults. Fourteen (46.7%) PCC/PGL children had germline mutations (VHL 10 [33.3%], SDHB 2 [6.6%], and SDHD 2 [6.6%]). Overall germline mutations (46.7% vs. 26.4%, p=0.04) and VHL mutations (33.3% vs. 10.9%, p=0.026) were significantly more common in children than in adults. In children with VHL mutations, bilateral PCC were more frequent than in adults with VHL mutations. Within the paediatric cohort, bilateral PCC (60% vs. 5%, p=0.002), PCC+sPGL (30% vs. 0%, p=0.03) and occurrence of a second PCC/PGL (30% vs. 0%, p=0.03) were significantly more frequent among children with VHL mutations than others.

CONCLUSIONS

All PCC/PGL children should be screened for germline mutations with first priority for VHL gene testing. Paediatric PCC/PGL patients with VHL mutations should be thoroughly evaluated for bilateral PCC and PCC+sPGL at initial presentation and closely followed up for occurrence of a second PCC/PGL.

A Comprehensive Review of Pediatric Tumors and Associated Cancer Predisposition Syndromes

An understanding of the role of inherited cancer predisposition syndromes in pediatric tumor diagnoses continues to develop as more information is learned through the application of genomic technology. Identifying patients and their relatives at an increased risk for developing cancer is an important step in the care of this patient population. The purpose of this review is to highlight various tumor types that arise in the pediatric population and the cancer predisposition syndromes associated with those tumors. The review serves as a guide for recognizing genes and conditions to consider when a pediatric cancer referral presents to the genetics clinic.

Pediatric patients with pheochromocytoma and paraganglioma should have routine preoperative genetic testing for common susceptibility genes in addition to imaging to detect extra-adrenal and metastatic tumors

BACKGROUND

Pediatric pheochromocytomas and paragangliomas are rare with limited data on the optimal management approach. The aim of this study was to determine the role of genetic testing and imaging to detect extra-adrenal and/or metastatic tumors in pediatric pheochromocytomas and paragangliomas.

METHODS

We performed a retrospective study of 55 patients diagnosed at ≤21 years of age with pheochromocytomas and paragangliomas with analysis of data on genetic testing and multimodal imaging.

RESULTS

Eighty percent of patients (n = 44/55) had a germline mutation. The majority were found to have either VHL (38%) or SDHB (25%) mutation. Pheochromocytoma was present in 67% (n = 37/55) of patients and was bilateral in 51% (n = 19/37). The majority of patients with bilateral pheochromocytomas had VHL (79%). Abdominal paragangliomas was present in 22% (n = 12/55), head and neck paragangliomas in 11% (n = 6/55), and thoracic paragangliomas in 2 of 55 patients. For paragangliomas, SDHx accounted for 72% (n = 13/18) of mutations. The rate of malignancy was 16% (n = 9/55), 56% of whom had SDHB mutations. In two-thirds of patients, functional imaging identified either extra-adrenal paragangliomas and/or metastatic disease.

CONCLUSION

The majority of pediatric patients with pheochromocytomas and paragangliomas have detectable germline mutations. Therefore, we suggest strongly that all pediatric patients with pheochromocytomas and paragangliomas undergo genetic testing and imaging to detect extra-adrenal paragangliomas and metastatic disease to guide treatment and follow-up.

Risk-reduction surgery in pediatric surgical oncology: A perspective

OBJECTIVE

A small percentage of pediatric solid cancers arise as a result of clearly identified inherited predisposition syndromes and nongenetic lesions. Evidence supports preemptive surgery for children with genetic [multiple endocrine neoplasia type 2 (MEN2), familial adenomatous polyposis syndrome (FAP), hereditary nonpolyposis colorectal cancer (HNPCC), and hereditary diffuse gastric cancer (HDGC) and nongenetic [thyroglossal duct cysts (TGDC), congenital pulmonary airway malformations (CPAM), alimentary tract duplication cysts (ATDC), and congenital choledochal cysts (CCC)] developmental anomalies. Our aim was to explore the utility of risk reduction surgery to treat and prevent cancer in children.

METHODS

A systematic review of the available peer-reviewed literature on PubMed was performed using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) search strategy, where possible. Search items included "risk reduction surgery", "hereditary cancer predisposition syndrome", "multiple endocrine neoplasia type 2", "familial adenomatous polyposis", "hereditary nonpolyposis colorectal cancer", "hereditary diffuse gastric cancer", "thyroglossal duct cysts", congenital pulmonary airway malformations", "alimentary tract duplication cysts", "malignant transformation", and "guidelines".

RESULTS

We identified 67 articles that met the inclusion criteria describing the indications for prophylactic surgery in surgical oncology. For the genetic predisposition syndromes, 7 studies were related to professional endorsed guidelines, 7 were related to surgery for MEN2, 11 were related to colectomy for FAP, 6 were related to colectomy for HNPCC, and 12 related to gastrectomy for HDGC. Articles for the nongenetic lesions included 5 for techniques related to TGDC resection, 9 for surgery for CPAMs, and 10 for resection of ATDCs. Guidelines and strategies varied significantly especially related to the extent and timing of surgical intervention; the exception was for the timing of thyroidectomy in children with MEN2.

CONCLUSION

Current evidence supporting prophylactic surgery in the management of pediatric cancer predisposition syndromes and nongenetic lesions is best delineated for thyroidectomy to prevent medullary thyroid cancer in children with MEN2 (Strength of Recommendation Grade B/C). Despite the lack of pediatric specific evidence-based recommendations regarding the appropriate extent and timing for risk-reduction surgery for FAP, HNPCC, HDGC and nongenetic anomalies, our review represents an opportunity towards understanding the postgenomic development of these lesions and provides current indications and techniques for preemptive cancer prevention surgery in children.

Pathophysiology and diagnosis of disorders of the adrenal medulla: focus on pheochromocytoma

The principal function of the adrenal medulla is the production and secretion of catecholamines. During stressful challenging conditions, catecholamines exert a pivotal homeostatic role. Although the main adrenomedullary catecholamine, epinephrine, has a wide array of adrenoreceptor-mediated effects, its absence does not cause life-threatening problems. In contrast, excess production of catecholamines due to an adrenomedullary tumor, specifically pheochromocytoma, results in significant morbidity and mortality. Despite being rare, pheochromocytoma has a notoriously bad reputation because of its potential devastating effects if undetected and untreated. The paroxysmal signs and symptoms and the risks of missing or delaying the diagnosis are well known for most physicians. Nevertheless, even today the diagnosis is still overlooked in a considerable number of patients. Prevention and complete cure are however possible by early diagnosis and appropriate treatment but these patients remain a challenge for physicians. Yet, biochemical proof of presence or absence of catecholamine excess has become more easy and straightforward due to developments in assay methodology. This also applies to radiological and functional imaging techniques for locating the tumor. The importance of genetic testing for underlying germline mutations in susceptibility genes for patients and relatives is increasingly recognized. Yet, the effectiveness of genetic testing, in terms of costs and benefits to health, has not been definitively established. Further improvement in knowledge of genotype-phenotype relationships in pheochromocytoma will open new avenues to a more rationalized and personalized diagnostic approach of affected patients.

Pheochromocytoma and paraganglioma: an endocrine society clinical practice guideline

OBJECTIVE

The aim was to formulate clinical practice guidelines for pheochromocytoma and paraganglioma (PPGL).

PARTICIPANTS

The Task Force included a chair selected by the Endocrine Society Clinical Guidelines Subcommittee (CGS), seven experts in the field, and a methodologist. The authors received no corporate funding or remuneration.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe both the strength of recommendations and the quality of evidence. The Task Force reviewed primary evidence and commissioned two additional systematic reviews.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, European Society of Endocrinology, and Americal Association for Clinical Chemistry reviewed drafts of the guidelines.

CONCLUSIONS

The Task Force recommends that initial biochemical testing for PPGLs should include measurements of plasma free or urinary fractionated metanephrines. Consideration should be given to preanalytical factors leading to false-positive or false-negative results. All positive results require follow-up. Computed tomography is suggested for initial imaging, but magnetic resonance is a better option in patients with metastatic disease or when radiation exposure must be limited. (123)I-metaiodobenzylguanidine scintigraphy is a useful imaging modality for metastatic PPGLs. We recommend consideration of genetic testing in all patients, with testing by accredited laboratories. Patients with paraganglioma should be tested for SDHx mutations, and those with metastatic disease for SDHB mutations. All patients with functional PPGLs should undergo preoperative blockade to prevent perioperative complications. Preparation should include a high-sodium diet and fluid intake to prevent postoperative hypotension. We recommend minimally invasive adrenalectomy for most pheochromocytomas with open resection for most paragangliomas. Partial adrenalectomy is an option for selected patients. Lifelong follow-up is suggested to detect recurrent or metastatic disease. We suggest personalized management with evaluation and treatment by multidisciplinary teams with appropriate expertise to ensure favorable outcomes.

Urinary free (unconjugated) metadrenalines in different hereditary forms of catecholamine-secreting phaeochromocytoma/paraganglioma

Background

Catecholamine-producing neuroendocrine tumours are found in chromaffin cells of the adrenal medulla (phaeochromocytoma) or extra-adrenal paraganglia (paraganglioma), known collectively as PPGLs. In approximately a quarter or more of cases of PPGL, these rare tumours arise as a result of germline mutations of several tumour susceptibility genes. At the Crosshouse laboratory, urine tests include free metadrenalines (fMAs) (also known as free metanephrines) which demonstrate superior sensitivity over that obtained by urinary vanillyl mandelic acid, catecholamines or plasma catecholamines in the diagnosis of PPGL. This retrospective audit was to determine if urinary fMAs offered discrimination among the hereditary forms of PPGL.

Methods

Retrospective biochemical and genetic data were gathered from 1997 to 2011. The identified urine specimens were those obtained at the time of first diagnosis or recurrence of PPGL. Results of catecholamines and metabolites were standardized as multiples of their respective relevant upper reference limits (URLs).

Results

Results were available for 29 affected patients (15 females and 14 males), median age 26 (range 9–63) years, comprising three mutation groups: succinate dehydrogenase subunit B or D ([SDHB/D] 16 patients), multiple endocrine neoplasia type 2 ([MEN 2] 6 patients) and von Hippel–Lindau disease ([VHL] 7 patients). The parent catecholamines exhibited increased values for noradrenaline (NA) and/or adrenaline (AD) for 25/29 (86.2%) patients. Either or both free normetadrenaline (fNMA) and fMA were elevated in 29/29 (100%) patients.

Conclusions

The ratio of the multiples of URL for fMA/fNMA displayed a clearer separation of MEN 2 patients from those with SDHB/D or VHL than did the equivalent AD/NA ratio.

Age-related medical decision limits for urinary free (unconjugated) metadrenalines, catecholamines and metabolites in random urine specimens from children

Background

Neuroblastoma is the most common extracranial solid tumour in childhood (8% of all childhood cancers), the most frequently diagnosed in infancy, and has one of the highest death rates, while chromaffin tumours rarely present in childhood. Both tumour types produce catecholamines and their metabolites. It is difficult to produce reference ranges for tests in children, and currently, no age-related medical decision limits for free metadrenalines (free metanephrines) in random urine specimens exist in the paediatric literature.

Methods

Results of vanillylmandelic acid (VMA), 5-hydroxyindoleacetic acid, homovanillic acid (HVA), noradrenaline (NA), adrenaline, dopamine (DA), free normetadrenaline (fNMA), free metadrenaline and free 3-methoxytyramine (f3MT) in 1658 random urines obtained from infants, children and young adults were measured by high performance liquid chromatography with electrochemical detection. Specimens were excluded from consideration if obtained from the following categories, i.e. (a) harbouring neuroblastic, chromaffin, carcinoid or other tumours or malignancies; (b) medical conditions having known association with excess catecholamine excretion; (c) patients administered catecholamine or paracetamol; (d) overly dilute urine; and (e) manifesting outlying values following visual inspection.

Results

There remained 872 specimens that were grouped into seven age ranges (<1; 1 or 2; 3 or 4; 5–7; 8–10; 11–13; 14–19 y) for which medical decision limits were determined for each analyte. There was no significant difference between the results for boys or girls. In 55 patients harbouring neuroblastic tumours, HVA (54/55), f3MT (14/16), VMA (45/53) and DA (43/53) were the most frequently elevated analytes at time of diagnosis. In 11 patients presenting in childhood with chromaffin tumours, fNMA (11/11) followed by NA (10/11) were the most frequently elevated.

Discussion

The likely reasons for outlying or missing values, together with the reasons for variation in the distinctive biochemical patterns of analytes exhibited in individuals harbouring either neuroblastic or chromaffin tumours are discussed.

The growing role for genetic counseling in endocrinology

PURPOSE OF REVIEW

The field of cancer genetics and genetic testing is expanding rapidly. As our understanding of the hereditary nature of endocrine tumors increases, the role of genetic counseling on the multidisciplinary endocrinology team is becoming more critical. This brief review will highlight the role of the certified genetic counselor in this setting.

RECENT FINDINGS

Genetic counseling and testing may aid in the management of the endocrine patient through early diagnosis and detection of disease, by optimizing surgical decision-making and improving overall survival. Certified genetic counselors assist the endocrinology team by eliciting a detailed pedigree, determining the appropriate genetic test to order, obtaining informed consent, interpreting complex genetic test results, providing psychosocial and family counseling, and assessing which family members are at risk. Many endocrine tumors can be caused by a variety of different genes and investment in the genetic counseling process likely increases the chance that the correct genetic test is ordered, results are interpreted accurately, and adequate informed consent and counseling is offered.

SUMMARY

The field of endocrine genetics is growing exponentially and testing will likely play an even greater role in surveillance, medical management, and surgical decision-making in the next decade. Genetic counseling both pretesting and posttesting is essential to accurate, cost-efficient care for the endocrine patient and the entire family.

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.