Preoperative multiple endocrine neoplasia type 1 diagnosis improves the surgical outcomes of pediatric patients with primary hyperparathyroidism

Primary Hyperparathyroidism due to Parathyroid Adenoma in Children and Adolescents

OBJECTIVE

In contrast to adults, primary hyperparathyroidism (PHPT) in children and adolescents is a rare endocrine disorder.

METHODS

A retrospective review of PHPT cases between 2005 and 2022 from a single tertiary university medical center, including clinical signs and symptoms, laboratory findings, radiological evaluation, treatment, and postoperative complications.

RESULTS

Ten children (mean age at diagnosis 16.3 ± 1.3 years) were diagnosed with PHPT. All patients were in late pubertal stages without sex predominance and 8 were symptomatic. Mean calcium level was 13.6 ± 2.5 mg/dL, and mean parathyroid hormone levels were 204.8 ± 163.1 pg/mL. Parathyroid adenoma was confirmed by the postsurgical pathology results.

CONCLUSIONS

PHPT in children and adolescents is often symptomatic and more severe than adults. The main cause is single parathyroid adenoma. Associated hypercalcemic syndromes were not found. Patients were cured after surgical removal of the adenoma without significant postoperative complications and no recurrence during 10.4 ± 5.9 years follow-up.

Molecular and Clinical Spectrum of Primary Hyperparathyroidism

Recent data suggest an increase in the overall incidence of parathyroid disorders, with primary hyperparathyroidism (PHPT) being the most prevalent parathyroid disorder. PHPT is associated with morbidities (fractures, kidney stones, chronic kidney disease) and increased risk of death. The symptoms of PHPT can be nonspecific, potentially delaying the diagnosis. Approximately 15% of patients with PHPT have an underlying heritable form of PHPT that may be associated with extraparathyroidal manifestations, requiring active surveillance for these manifestations as seen in multiple endocrine neoplasia type 1 and 2A. Genetic testing for heritable forms should be offered to patients with multiglandular disease, recurrent PHPT, young onset PHPT (age ≤40 years), and those with a family history of parathyroid tumors. However, the underlying genetic cause for the majority of patients with heritable forms of PHPT remains unknown. Distinction between sporadic and heritable forms of PHPT is useful in surgical planning for parathyroidectomy and has implications for the family. The genes currently known to be associated with heritable forms of PHPT account for approximately half of sporadic parathyroid tumors. But the genetic cause in approximately half of the sporadic parathyroid tumors remains unknown. Furthermore, there is no systemic therapy for parathyroid carcinoma, a rare but potentially fatal cause of PHPT. Improved understanding of the molecular characteristics of parathyroid tumors will allow us to identify biomarkers for diagnosis and novel targets for therapy.

Pediatric primary hyperparathyroidism: Surgical pathology and long-term outcomes in sporadic and familial cases

BACKGROUND

Primary Hyperparathyroidism (PHPT) is rare in pediatric patients. Data regarding surgical outcomes are scarce.

METHODS

Single-center retrospective review (1994-2020) of patients ≤21 years undergoing surgery for PHPT.

RESULTS

66 patients were identified (61% female, 17 ± 3 years). 71% of patients were symptomatic at diagnosis. 32% of patients had known familial syndromes, most commonly MEN-1. 23% of patients without a known mutation had genetic testing, 22% positive. 56% of the total and 19% of the familial cohort underwent focused exploration. Single gland disease was found in 19% of familial vs 85% of sporadic cases, p < 0.00001. Persistence was 9%, all in the sporadic group, p = 0.11. Recurrence was 15%: 38% in the familial vs 2% in the sporadic groups, p=0.0004. Time to recurrence was 59 months (Q1-38, Q3-95), familial 61 vs 124 months sporadic, p=0.001.

CONCLUSION

Pediatric PHPT is frequently sporadic, although 5% of apparent sporadic cases are secondary to syndromes. Familial cases have higher rates of recurrence, requiring closer follow-up.

Multiple Endocrine Neoplasia Type 1: Latest Insights

Multiple endocrine neoplasia type 1 (MEN1), a rare tumor syndrome that is inherited in an autosomal dominant pattern, is continuing to raise great interest for endocrinology, gastroenterology, surgery, radiology, genetics, and molecular biology specialists. There have been 2 major clinical practice guidance papers published in the past 2 decades, with the most recent published 8 years ago. Since then, several new insights on the basic biology and clinical features of MEN1 have appeared in the literature, and those data are discussed in this review. The genetic and molecular interactions of the MEN1-encoded protein menin with transcription factors and chromatin-modifying proteins in cell signaling pathways mediated by transforming growth factor β/bone morphogenetic protein, a few nuclear receptors, Wnt/β-catenin, and Hedgehog, and preclinical studies in mouse models have facilitated the understanding of the pathogenesis of MEN1-associated tumors and potential pharmacological interventions. The advancements in genetic diagnosis have offered a chance to recognize MEN1-related conditions in germline MEN1 mutation-negative patients. There is rapidly accumulating knowledge about clinical presentation in children, adolescents, and pregnancy that is translatable into the management of these very fragile patients. The discoveries about the genetic and molecular signatures of sporadic neuroendocrine tumors support the development of clinical trials with novel targeted therapies, along with advancements in diagnostic tools and surgical approaches. Finally, quality of life studies in patients affected by MEN1 and related conditions represent an effort necessary to develop a pharmacoeconomic interpretation of the problem. Because advances are being made both broadly and in focused areas, this timely review presents and discusses those studies collectively.

Management of familial hyperparathyroidism syndromes: MEN1, MEN2, MEN4, HPT-Jaw tumour, Familial isolated hyperparathyroidism, FHH, and neonatal severe hyperparathyroidism

While primary hyperparathyroidism (PHPT) generally represents a common endocrine disorder, being the more frequent cause of hypercalcemia in outpatients, familial forms of PHPT (FPHPT) account for no more than 2-5% of the overall PHPT. In the last decades, many technical progresses in both molecular and biochemical-radiological evaluation have been made, and substantial advancements in understanding these disorders have been reached. Differences both in the pathogenesis and clinical presentation exist among the various hyperparathyroid syndromic forms, and, since FPHPT is frequently associated to other endocrine, proliferative and/or functional disorders, as also non-endocrine tumours, with varying clinical spectrum of occurrence in each syndrome, its early clinically detection for appropriately preventing complications (i.e. kidney and bone disorders) is strictly advised. In this review, the clinical-biochemical features and diagnostic procedures of each FPHPT form will be summarized and a general overview on surgical and pharmacological approaches to FPHPT has been also considered.

Intraoperative Decision-Making and Technical Aspects of Parathyroidectomy in Young Patients With MEN1 Related Hyperparathyroidism

One in 5,000 to 1 in 50,000 births have multiple endocrine neoplasia type 1 (MEN1). MEN1 is a hereditary syndrome clinically defined by the presence of two of the following endocrine tumors in the same patient: parathyroid adenomas, entero-pancreatic endocrine tumors and pituitary tumors. Most commonly, patients with MEN1 manifest primarily with signs and symptoms linked to primary hyperparathyroidism. By age 50, it is estimated that 100% of patients with MEN1 will have been diagnosed with primary hyperparathyroidism. These patients will need to undergo resection of their hyperfunctioning glands, however there is no clear consensus on which procedure to perform and when to perform it in these patients. In this original study we describe and explain the rational of our peri-operative approach and management at MD Anderson Cancer Center of MEN1 patients with hyperparathyroidism. This protocol includes preoperative evaluation, intraoperative decision-making and detailed surgical technique adopted for these patients' care. Additionally we review follow-up and disease management in instances of recurrent primary hyperparathyroidism in patients with MEN1 syndrome.

The future: diagnostic and imaging advances in MEN1 therapeutic approaches and management strategies

Prospective randomized data are lacking, but current clinical expert guidelines recommend annual screening examinations, including laboratory assessments and various imaging modalities (e.g. CT, MRI, scintigraphy and EUS) for patients with multiple endocrine neoplasia type 1 (MEN1). Routine screening is proposed to detect and localize neuroendocrine manifestations as early as possible. The goal is timely intervention to improve quality of life and to increase life expectancy by preventing the development of life-threatening hormonal syndromes and/or metastatic disease. In recent years, some studies compared different and new imaging methods regarding their sensitivity and utility in MEN1 patients. This present article reviews the proposed diagnostic tools for MEN1 screening as well as potential future perspectives.

Multiple endocrine neoplasia syndromes 1 and 2: manifestations and management in childhood and adolescence

The identification of the genetic causes of the multiple endocrine neoplasia (MEN) syndromes 1 and 2, and associated genotype-phenotype relationships, has revolutionised the clinical care of affected patients. A genetic diagnosis can be made during infancy and careful clinical surveillance, coupled with early intervention, has the potential to improve both morbidity and mortality. These developments have seen the management of patients with MEN move into the arena of paediatric medicine. In this review article, we consider the genetic causes of MEN together with the clinical manifestations and management of these syndromes.

Focused image-guided parathyroidectomy in the current management of primary hyperparathyroidism

OBJECTIVE

Primary hyperparathyroidism (PHPT) in childhood and adolescence has been considered a different disease to that seen in adults, with predominantly familial aetiology mandating open exploration to exclude parathyroid hyperplasia in contrast to the adoption of focused image-guided parathyroidectomy (FP) in adults.

STUDY DESIGN

A retrospective cohort study in a tertiary referral hospital setting of all children and adolescents (<18 years) undergoing parathyroid surgery for PHPT. Data were obtained from a dedicated endocrine surgery database and hospital medical records.

RESULTS

Over the 35-year study period (1980-2014), there were 31 patients who underwent parathyroidectomy for PHPT. 3 patients were from known multiple endocrine neoplasia type 1 syndrome (MEN1) families, 3 had an isolated family history of PHPT and 25 were sporadic. In the sporadic group, 24 (96%) presented with symptomatic hypercalcaemia, affecting the gastrointestinal, musculoskeletal, genitourinary or neuropsychiatric systems. In the 25 patients with sporadic PHPT, nine (36%) had FP with a single adenoma removed with a 100% initial cure rate. Sixteen patients (64%) in the sporadic group had an open exploration: 14 had single gland disease while 2 patients required a second procedure to achieve a final cure rate of 100%. Of the three patients with MEN1, one was cured, one has persistent hyperparathyroidism after FP and the third has permanent hypoparathyroidism after open exploration.

CONCLUSIONS

The majority of children and adolescents with PHPT have symptomatic disease due to a single adenoma. They can therefore be managed in a similar fashion to their adult counterparts with preoperative localisation studies aiming to permit FP in a day case setting.