Surgery for multiple endocrine neoplasia type 1-associated primary hyperparathyroidism

Microwave ablation for recurrent primary hyperparathyroidism in four patients with multiple endocrine neoplasia type 1: a case series report

Multiple endocrine neoplasia type 1 (MEN1), a rare tumor syndrome, is inherited in an autosomal dominant pattern, mainly manifested as primary hyperparathyroidism (PHPT). Surgery is preferred for patients with MEN1 and PHPT. Thermal ablation has been widely applied for PHPT but rarely for postoperative recurrent PHPT in MEN1 patients. Based on a series of cases, we aimed to investigate the clinical efficacy and safety of ultrasound-guided percutaneous microwave ablation in the treatment of MEN1 patients with postoperative recurrence of PHPT.

Recurrence After Surgery for Primary Hyperparathyroidism in 517 Patients With Multiple Endocrine Neoplasia Type 1: An Association Francophone de Chirurgie Endocrinienne and Groupe d'étude des Tumeurs Endocrines study

OBJECTIVE

To assess recurrence according to the type of surgery for primary hyperparathyroidism (pHPT) in multiple endocrine neoplasia type 1 ( MEN1 ) patients and to identify the risk factors for recurrence after the initial surgery.

BACKGROUND

In MEN1 patients, pHPT is multiglandular, and the optimal extent of initial parathyroid resection influences the risk of recurrence.

METHODS

MEN1 patients who underwent initial surgery for pHPT between 1990 and 2019 were included. Persistence and recurrence rates after less than subtotal parathyroidectomy (LTSP) and subtotal parathyroidectomy (STP) were analyzed. Patients with total parathyroidectomy with reimplantation were excluded.

RESULTS

Five hundred seventeen patients underwent their first surgery for pHPT: 178 had LTSP (34.4%) and 339 STP (65.6%). The recurrence rate was significantly higher after LTSP (68.5%) than STP (45%) ( P < 0.001). The median time to recurrence after pHPT surgery was significantly shorter after LTSP than after STP: 4.25 (1.2-7.1) versus 7.2 (3.9-10.1) years ( P < 0.001). A mutation in exon 10 was an independent risk factor of recurrence after STP (odds ratio = 2.19; 95% CI: 1.31; 3.69; P = 0.003). The 5 and 10-year recurrent pHPT probabilities were significantly higher in patients after LTSP with a mutation in exon 10 (37% and 79% vs 30% and 61%; P = 0.016).

CONCLUSIONS

Persistence, recurrence of pHPT, and reoperation rate are significantly lower after STP than LTSP in MEN1 patients. Genotype seems to be associated with the recurrence of pHPT. A mutation in exon 10 is an independent risk factor for recurrence after STP, and LTSP may not be recommended when exon 10 is mutated.

Primary hyperparathyroidism in patients with multiple endocrine neoplasia type 1: Impact of genotype and surgical approach on long-term postoperative outcomes

BACKGROUND

Protein-truncating germline pathogenic variants in the N- and C-terminal exons (2, 9, and 10) of the MEN1 gene may be associated with aggressive pancreatic neuroendocrine tumors. However, the impact of these variants on parathyroid disease is poorly understood. We sought to investigate the effects of genotype and surgical approach on clinical phenotype and postoperative outcomes in patients with multiple endocrine neoplasia type 1 (MEN1)-related primary hyperparathyroidism.

METHODS

We identified patients with MEN1 evaluated at our institution from 1985 to 2020 and stratified them by genotype, (truncating variants in exons 2, 9, or 10, or other variants), and index surgical approach, (less-than-subtotal parathyroidectomy [

RESULTS

Of the 209 patients we identified, primary hyperparathyroidism was diagnosed in 194 (93%) and at a younger median age in those with truncating exon 2, 9, or 10 variants compared with other variants (27 years vs 31 years; P = .006). Median disease-free survival was significantly worse in patients who underwent

CONCLUSION

The MEN1 genotype may affect the age of onset of primary hyperparathyroidism and the time to recurrence after surgery. Collapse

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MESH Headings

• Humans
• Adult
• Multiple Endocrine Neoplasia Type 1/complications
• Multiple Endocrine Neoplasia Type 1/genetics
• Multiple Endocrine Neoplasia Type 1/surgery
• Hyperparathyroidism, Primary/genetics
• Hyperparathyroidism, Primary/surgery
• Hyperparathyroidism, Primary/epidemiology
• Neoplasm Recurrence, Local/surgery
• Parathyroidectomy/adverse effects
• Hypoparathyroidism/etiology
• Genotype

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Grants Collapse

Affiliation(s)

Omair A Shariq Department of Surgery, Mayo Clinic, Rochester, MN.
Vitor B Abrantes Department of Surgery, Mayo Clinic, Rochester, MN
Lauren Y Lu Department of Surgery, Mayo Clinic, Rochester, MN
Peter J Tebben Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, MN
Trenton M Foster Department of Surgery, Mayo Clinic, Rochester, MN
Benzon M Dy Department of Surgery, Mayo Clinic, Rochester, MN
Melanie L Lyden Department of Surgery, Mayo Clinic, Rochester, MN
William F Young Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, MN
Travis J McKenzie Department of Surgery, Mayo Clinic, Rochester, MN

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Collaborators Collapse

A contemporary analysis of the pre- and intraoperative recognition of multigland parathyroid disease

BACKGROUND

Despite advances in biochemical and radiological identification of parathyroid gland enlargement, primary hyperparathyroidism (PHPT) due to sporadic multigland parathyroid disease (MGPD) remains a perioperative diagnostic dilemma. Failure to recognise MGPD pre- or intraoperatively may negatively impact surgical cure rates and result in persistent PHPT and ongoing patient morbidity.

METHODS

We have conducted a comprehensive review of published literature in attempt to determine factors that could aid in reliably diagnosing sporadic MGPD pre- or intraoperatively. We discuss preoperative clinical features and examine pre- and intraoperative biochemical and imaging findings concentrating on those areas that give practicing surgeons and the wider multi-disciplinary endocrine team indications that a patient has MGDP. This could alter surgical strategy.

CONCLUSION

Biochemistry can provide diagnosis of PHPT but cannot reliably discriminate parathyroid pathology. Histopathology can aid diagnosis between MGPD and adenoma, but histological appearance can overlap. Multiple negative imaging modalities indicate that MGPD may be more likely than a single parathyroid adenoma, but the gold standard for diagnosis is still intraoperative identification during BNE. MGPD remains a difficult disease to both diagnose and treat.

Ultrasound-guided microwave ablation in the treatment of recurrent primary hyperparathyroidism in a patient with MEN1: a case report

Background

Multiple endocrine neoplasia type 1 (MEN1) is an inherited endocrine syndrome caused by the mutation in the tumor suppressor gene MEN1. The recurrence rate of primary hyperparathyroidism (PHPT) in patients with MEN1 after parathyroidectomy remains high, and the management of recurrent hyperparathyroidism is still challenging.

Case presentation

We reported a 44-year-old woman with MEN1 combined with PHPT who was diagnosed through genetic screening of the patient and her family members. After parathyroidectomy to remove one parathyroid gland, the patient suffered from persistent high levels of serum calcium and parathyroid hormone, which returned to normal at up to 8 months after ultrasound-guided microwave ablation (MWA) for bilateral parathyroid glands, suggesting an acceptable short-term prognosis.

Conclusion

Ultrasound-guided MWA for parathyroid nodules may be an effective therapeutic strategy for recurrent PHPT in MEN1 patients.

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.

[Special features of the diagnostics and treatment of hereditary primary hyperparathyroidism]

Between 2% and 10% of patients with primary hyperparathyroidism (pHPT) are diagnosed with hereditary forms of primary hyperparathyroidism (hpHPT). They are more prevalent in younger patients before the age of 40 years, in patients with persistence or recurrence of pHPT and pHPT patients with multi-glandular disease (MGD). The various forms of hpHPT diseases can be classified into four syndromes, i.e., hpHPT associated with diseases of other organ systems, and four diseases that are confined to the parathyroid glands. Approximately 40% of patients with hpHPT suffer from multiple endocrine neoplasia type 1 (MEN-1) or show germline mutations of the MEN‑1 gene. Currently, germline mutations that lead to a specific diagnosis in patients with hpHPT have currently been described in 13 different genes, which enables a clear diagnosis of the disease; however, a clear genotype-phenotype correlation does not exist, even though the complete loss of a coded protein (e.g. due to frame-shift mutations in the calcium sensing receptor, CASR) often leads to more severe clinical consequences than merely a reduced function of the protein (e.g. due to point mutation). As the various hpHPT diseases require different treatment approaches, which do not correspond to that of sporadic pHPT, a clear definition of the specific form of hpHPT must always be strived for. Therefore, before surgery of a pHPT with clinical, imaging or biochemical suspicion of hpHPT, genetic proof or exclusion of hpHPT is necessary. The differentiated treatment approach for hpHTP can only be defined by taking the clinical and diagnostic results of all the abovenamed findings into account.

Less Than Subtotal Parathyroidectomy for Multiple Endocrine Neoplasia Type 1 Primary Hyperparathyroidism: A Systematic Review and Meta-Analysis

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1)-associated primary hyperparathyroidism (pHPT) is classically associated with an asymmetric and asynchronous parathyroid involvement. Subtotal parathyroidectomy (STP), which is currently the recommended surgical treatment, carries a high risk of permanent hypoparathyroidism. The results of less than subtotal parathyroidectomy (LSTP) are conflicting, and its place in this setting is still a matter of debate. The aim of this study was to identify the place of LSTP in the surgical management of patients with MEN-associated pHPT.

METHODS

A systematic literature review was conducted in accordance with PRISMA and MOOSE guidelines, for studies comparing STP and LSTP for MEN1-associated pHPT. The results of the two techniques, regarding permanent hypoparathyroidism, persistent hyperparathyroidism and recurrent hyperparathyroidism were computed using pairwise random-effect meta-analysis.

RESULTS

Twenty-five studies comparing STP and LSTP qualified for inclusion in the quantitative synthesis. In total, 947 patients with MEN1-associated pHPT were allocated to STP (n = 569) or LSTP (n = 378). LSTP reduces the risk of permanent hypoparathyroidism [odds ratio (OR) 0.29, confidence interval (CI) 95% 0.17-0.49)], but exposes to higher rates of persistent hyperparathyroidism [OR 4.60, 95% CI 2.66-7.97]. Rates of recurrent hyperparathyroidism were not significantly different between the two groups [OR 1.26, CI 95% 0.83-1.91].

CONCLUSIONS

LSTP should not be abandoned and should be considered as a suitable surgical option for selected patients with MEN1-associated pHPT. The increased risk of persistent hyperparathyroidism could improve with the emergence of more efficient preoperative localization imaging techniques and a more adequate patients selection.

Primary hyperparathyroidism: Disease of diverse genetic, symptomatic, and biochemical phenotypes

Genetic, symptomatic, and biochemical heterogeneity of patients with primary hyperparathyroidism (PHPT) has become apparent in recent years. An in-depth, evidence-based review of the phenotypes of PHPT was conducted. This review was intended to provide the resulting information to surgeons who operate on patients with hyperparathyroidism. This review revealed that the once relatively clear distinction between familial and sporadic PHPT has become more challenging by the finding of various germline mutations in patients with seemingly sporadic PHPT. On the one hand, the genetic and clinical characteristics of some syndromes in which PHPT is an important component are now better understood. On the other hand, knowledge is emerging about novel syndromes, such as the rare multiple endocrine neoplasia type IV (MEN4), in which PHPT occurs frequently. It also revealed that, currently, the classical array of symptoms of PHPT is seen rarely upon initial presentation for evaluation. More common are nonspecific, nonclassical symptoms and signs of PHPT. In areas of the world where serum calcium levels are checked routinely, most patients today are "asymptomatic" and they are diagnosed after an incidental finding of hypercalcemia; however, some of them have subclinical involvement of bones and kidneys, which is demonstrated on radiographs, ultrasound, and modern imaging techniques. Last, the review points out that there are three distinct biochemical phenotypes of PHPT. The classical phenotype in which calcium and parathyroid hormone levels are both elevated, and other disease presentations in which the serum levels of calcium or intact parathyroid hormone are normal. Today several, distinct phenotypes of the disease can be identified, and they have implications in the diagnostic evaluation and treatment of patients, as well as possible screening of relatives.

Multimodality Imaging Review of Multiple Endocrine Neoplasia

OBJECTIVE. The purpose of this article is to review the clinical manifestations, endocrine tumors types, and multimodality diagnostic tools available to physicians involved in the management of patients with multiple endocrine neoplasia (MEN) syndrome, in addition to discussing relevant imaging findings and appropriate imaging follow-up. CONCLUSION. Thorough knowledge of the spectrum of tumors associated with MEN gene mutations aids in the screening, diagnostic workup, and posttreatment monitoring of patients with MEN-related gene mutations.

Management of primary and renal hyperparathyroidism: guidelines from the German Association of Endocrine Surgeons (CAEK)

BACKGROUND AND AIMS

The purpose of this review is to provide updated recommendations for the surgical management of primary (pHPT) and renal (rHPT) hyperparathyroidism, formulating a new guideline of the German Association of Endocrine Surgeons (CAEK).

METHODS

Evidence-based recommendations for the diagnosis and therapy of pHPT and rHPT were assessed by a multidisciplinary panel using PubMed for a comprehensive literature search together with a structured consensus dialogue (S2k guideline of the Association of the German Scientific Medical Societies, AWMF).

RESULTS

During the last 20 years, a variety of new preoperative localization procedures, such as sestamibi-SPECT, 4D-CT, and various PET/CT procedures, were established for pHPT. High-resolution imaging, together with intraoperative parathyroid hormone (IOPTH) measurement, enabled focused or minimally invasive surgery to become the most favored surgical technique. Patients with pHPT and nonlocalizing imaging have a higher risk of multiglandular disease. Surgical therapy provides very high cure rates, with a clear relation to the surgeon's experience in parathyroid procedures. Reoperative parathyroidectomy, children with pHPT or familial forms, and parathyroid carcinoma are addressed and require special surgical expertise. A multidisciplinary team of experienced nephrologists, transplant, and endocrine surgeons should assess the diagnosis and treatment of renal HPT.

CONCLUSION

Surgery is the only curative treatment for pHPT and should be considered for all patients with pHPT. For rHPT, a more selective approach is required, and parathyroidectomy is indicated only when conservative treatment options fail. In parathyroid carcinoma, the adequacy of local resection influences local disease control.

New therapies for patients with multiple endocrine neoplasia type 1

In 1953, for the first time, Paul Wermer described a family presenting endocrine gland neoplasms over several generations. The transmission was autosomal dominant and the penetrance was high. Forty years later in 1997, the multiple endocrine neoplasia type 1 (MEN1) gene was sequenced, thus enabling diagnosis and early optimal treatment. Patients carrying the MEN1 gene present endocrine but also non-endocrine tumors. Parathyroid, pancreatic and pituitary impairment are the three main types of endocrine involvement. The present article details therapeutic management of hyperparathyroidism, neuroendocrine pancreatic tumors and pituitary adenomas in patients carrying the MEN1 gene. Significant therapeutic progress has in fact been made in the last few years. As concerns the parathyroid glands, screening of family members and regular monitoring of affected subjects now raise the question of early management of parathyroid lesions and optimal timing of parathyroid surgery. As concerns the duodenum-pancreas, proton-pump inhibitors are able to control gastrin-secreting syndrome, reducing mortality in MEN1 patients. Mortality in MEN1 patients is no longer mainly secondary to uncontrolled hormonal secretion but to metastatic (mainly pancreatic) disease progression. Tumor risk requires regular monitoring of morphological assessment, leading to iterative pancreatic surgery in a large number of patients. Finally, pituitary adenomas in MEN1 patients are traditionally described as aggressive, invasive and resistant to medical treatment. However, regular pituitary screening showed them to be in fact infra-centimetric and non-secreting in the majority of patients. Consequently, it is necessary to regularly monitor MEN1 patients, with regular clinical, biological and morphological work-up. Several studies showed that this regular monitoring impairs quality of life. Building a relationship of trust between patients and care provider is therefore essential. It enables the patient to be referred for psychological or psychiatric care in difficult times, providing long-term support and preventing any breakdown in continuity of care.

Less than subtotal parathyroidectomy in multiple endocrine neoplasia type 1: A case report and review of the literature

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Traditionally, the surgical approach for primary hyperparathyroidism in MEN1 is either subtotal or total parathyroidectomy.

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Advances in medical imaging allows more accurate preoperative localization of abnormal parathyroid gland.

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Recent studies showed less than subtotal parathyroidectomy has comparable outcome compared to subtotal or total parathyroidectomy.

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Further studies are needed to determine whether there are subsets of MEN1 patients that can benefit from less than subtotal parathyroidectomy.

Introduction

Multiple endocrine neoplasia type 1 (MEN1) is a rare syndrome with common presenting signs and symptoms secondary to primary hyperparathyroidism (PHPT), which is managed surgically. Traditionally, either subtotal parathyroidectomy (SPTX) or total parathyroidectomy with autologous transplantation (TPTX) is the approach of choice. However, recent studies showed comparable persistence and recurrence rate in a subset of MEN1 patients (two or more concordant preoperative imaging results) who underwent less than subtotal parathyroidectomy (LSPTX).

Presentation of case

We report a case of patient with PHPT and delayed diagnosis of MEN1, who underwent LSPTX without intraoperative parathyroid hormone (IOPTH) measurement. The approach was chosen based on the preoperative imaging studies. Unfortunately, the PHPT persisted and the patient was reoperated. To further elucidate the issue, a systematic search of the literature was conducted on Cochrane library, PubMed, and Scopus; articles relevant to the case were reviewed. Results are conflicting results with most of the studies showed LSPTX is inferior compared to the other two approaches.

Discussion

Therefore, given the current body of evidence, we consider that subtotal or total parathyroidectomy is still the preferred surgical approach for the treatment of PHPT in MEN1.

Conclusion

Further studies are still needed to see whether LSPTX is comparable to SPTX or TPTX in regards to persistent and recurrent hyperparathyroidism if the conditions are met.

Optimal extent of initial parathyroid resection in patients with multiple endocrine neoplasia syndrome type 1: A meta-analysis

BACKGROUND

Hyperparathyroidism is an almost universal feature of multiple endocrine neoplasia type 1 syndrome. We present a systematic review and meta-analysis of the postoperative outcomes of patients undergoing initial operative treatment of primary hyperparathyroidism complicating multiple endocrine neoplasia 1.

METHODS

A comprehensive literature search was performed with a priori defined exclusion criteria for studies comparing total parathyroidectomy, subtotal parathyroidectomy, and less than subtotal parathyroidectomy.

RESULTS

Twenty-one studies incorporating 1,131 patients (272 undergoing total parathyroidectomy, 510 subtotal parathyroidectomy, and 349 less than subtotal parathyroidectomy) were identified. Pooled results revealed increased risk for long-term hypoparathyroidism in total parathyroidectomy patients (relative risk 1.61; 95% confidence interval, 1.12-2.31; P = .009) versus those undergoing subtotal parathyroidectomy. In the less than subtotal parathyroidectomy or subtotal parathyroidectomy comparison group, a greater risk for recurrence of hyperparathyroidism (relative risk 1.37; 95% confidence interval, 1.05-1.79; P = .02), persistence of hyperparathyroidism (relative risk 2.26; 95% confidence interval, 1.49-3.41; P = .0001), and reoperation for hyperparathyroidism (relative risk 2.48; 95% confidence interval, 1.65-3.73; P < .0001) was noted for less than subtotal parathyroidectomy patients, albeit with lesser risk for long-term for hypoparathyroidism (relative risk 0.47; 95% confidence interval, 0.29-0.75; P = .002).

CONCLUSION

Subtotal parathyroidectomy compares favorably to total parathyroidectomy, exhibiting similar recurrence and persistence rates with a decreased propensity for long-term postoperative hypoparathyroidism. The benefit of the decreased risk of hypoparathyroidism in less than subtotal parathyroidectomy is negated by the increase in the risk for recurrence, persistence, and reoperation. Future studies evaluating the performance of less than subtotal parathyroidectomy in specific multiple endocrine neoplasia 1 phenotypes should be pursued in an effort to delineate a patient-tailored, operative approach that optimizes long-term outcomes.

Single gland excision for MEN1-associated primary hyperparathyroidism

IMPORTANCE

Guidelines advocate subtotal parathyroidectomy (SPTX) or total parathyroidectomy with autotransplantation (TPTX) with bilateral cervical thymectomy for primary hyperparathyroidism (pHPT) associated with multiple endocrine neoplasia type 1 (MEN1). However, both procedures are associated with a significant risk of permanent hypoparathyroidism.

OBJECTIVE

The aim of the current study was to compare long-term results of either single gland excision (SGE, 1-2 glands), SPTX and TPTX for the treatment of MEN1-associated pHPT.

DESIGN AND SETTING

Data of genetically confirmed MEN1 patients who underwent surgery for pHPT between 1987 and 2017 were retrieved from a prospective database and were retrospectively analysed.

RESULTS

Eighty-nine MEN1 patients underwent either TPTX (n = 38, 42.7%), SPTX (n = 23, 25.8%) or SGE (n = 28, 31.5%). The rate of disease persistence after initial surgery was 2.6%, 0% and 14.2% in the TPTX, SPTX and SGE groups, respectively. After median follow-up of 112 (range 7-411) months, the rate of recurrent pHPT was significantly higher in the SGE group (n = 19, 21.3%) compared with the TPTX (n = 4, 4.4%, P = .001) and the SPTX (n = 9, 10.1%, P = .03) groups. Analysis of the recurrence-free time among the surgical groups revealed a significant difference (P = .036). The median time to recurrence was significantly shorter after SGE (101, range 3-301 months) than after SPTX (139, range 28-278 months, P = .018) and TPTX (204, range 75-396 months, P = .049). Twelve (32%) patients who underwent TPTX developed permanent hypoparathyroidism compared with only 4 (17%, P = .06) in the SPTX and 0 in the SGE group (P = .001).

CONCLUSION

Given the high rate of postoperative permanent hypoparathyroidism after TPTX and SPTX, SGE is a valid option for the treatment of MEN1-associated pHPT.

MEN1-associated primary hyperparathyroidism in the Spanish Registry: clinical characterictics and surgical outcomes

Primary hyperparathyroidism is the most frequent manifestation of multiple endocrine neoplasia type 1 (MEN1) syndrome. Bone and renal complications are common. Surgery is the treatment of choice, but the best timing for surgery is controversial and predictors of persistence and recurrence are not well known. Our study describes the clinical characteristics and the surgical outcomes, after surgery and in the long term, of the patients with MEN1 and primary hyperparathyroidism included in the Spanish Registry of Multiple Endocrine Neoplasia, Pheochromocytomas and Paragangliomas (REGMEN). Eighty-nine patients (49 men and 40 women, 34.2 ± 13 years old) were included. Sixty-four out of the 89 underwent surgery: a total parathyroidectomy was done in 13 patients, a subtotal parathyroidectomy in 34 and a less than subtotal parathyroidectomy in 15. Remission rates were higher after a total or a subtotal parathyroidectomy than after a less than subtotal (3/4 and 20/22 vs 7/12, P < 0.05), without significant differences in permanent hypoparathyroidism (1/5, 9/23 and 0/11, N.S.). After a median follow-up of 111 months, 20 of the 41 operated patients with long-term follow-up had persistent or recurrent hyperparathyroidism. We did not find differences in disease-free survival rates between different techniques, patients with or without permanent hypoparathyroidism and patients with different mutated exons, but a second surgery was more frequent after a less than subtotal parathyroidectomy.

Concomitant Thyroid Cancer in Patients with Multiple Endocrine Neoplasia Type 1 Undergoing Surgery for Primary Hyperparathyroidism

BACKGROUND

Compared to those with sporadic primary hyperparathyroidism (SPHP), multiple endocrine neoplasia type 1 (MEN1) patients with primary hyperparathyroidism (MPHP) typically require more extensive dissection and have higher recurrence rates. Little is known about the risk of concomitant thyroid cancer in either setting. This study aimed to determine the rates and characteristics of thyroid cancer for MPHP versus SPHP patients undergoing parathyroidectomy.

METHODS

Patients with MPHP (diagnosed by clinical and/or genetic criteria) or SPHP who had initial or reoperative parathyroid exploration from 1967 to 2014 were identified via a prospective database. The thyroid cancer-specific data for MPHP patients (n = 29) were compared to a selected 2:1 age- and sex-matched SPHP cohort (n = 58) who all had concurrent thyroidectomy for any reason. Clinically significant thyroid cancer was defined as >1 cm in diameter.

RESULTS

In the MPHP group, 24/29 (83%) thyroidectomies were preoperatively unplanned versus 20/58 (34%) in the SPHP matched cohort (p < 0.01), and in this setting there was no difference in the rate of histologic thyroid cancer (3/24 [13%] vs. 5/20 [25%], p = 0.44). Histologic thyroid cancer was identified in 8/29 (28%) MPHP versus 27/58 (47%) SPHP patients (p = 0.11). Despite observed differences in the time period and extent of thyroidectomy, MPHP patients did not have an increased likelihood of thyroid cancer (surgery before 2005: odds ratio [OR] = 2.57, p = 0.09; total thyroidectomy: OR = 5.47, p < 0.01; MPHP: OR = 1.14, p = 0.83). All MPHP thyroid cancers were characterized as conventional papillary thyroid cancer (PTC), while thyroid cancers in SPHP patients included both PTC (66%) and follicular-variant PTC (34%). No MPHP patient had clinically significant thyroid cancer compared to an incidence of 15/58 (26%) in SPHP patients (p < 0.01).

CONCLUSIONS

Although patients with MEN1 have a substantial incidence of thyroid cancer (28%) and undergo more unplanned thyroidectomies during parathyroidectomy than do patients with SPHP, clinically significant thyroid cancer is proportionally uncommon.

Impact of "Tailored" Parathyroidectomy for Treatment of Primary Hyperparathyroidism in Patients with Multiple Endocrine Neoplasia Type 1

BACKGROUND

Whether total parathyroidectomy (TPTX) or subtotal parathyroidectomy (SPTX) should be performed for primary hyperparathyroidism (PHPT) in patients with multiple endocrine neoplasia type 1 (MEN1) is controversial. At our institution, the parathyroidectomy strategy is based on the number of enlarged intraoperative parathyroid glands. We retrospectively analyzed our parathyroidectomy procedures.

METHODS

Data of PHPT treatment in patients with MEN1 who underwent parathyroidectomy from 1982 to 2012 at our department were retrospectively collected. The data were grouped according to the surgical procedure: TPTX, SPTX, and less than SPTX (LPTX). TPTX or SPTX was selected based on the preoperative examination findings and number of enlarged intraoperative parathyroid glands. The outcomes were the disease-free survival (DFS) rate and postoperative calcium replacement rate based on Kaplan-Meier analysis for each type of surgical procedure.

RESULTS

Forty-five patients were analyzed. The overall 5- and 10-year DFS was 91.7 and 55.8%, respectively. The 5- and 10-year DFS in each subgroup was 100.0 and 85.7% in the TPTX group, 89.4 and 57.3% in the SPTX group, and 91.6 and 57.3% in the LPTX group, respectively. The postoperative calcium replacement rate at 1 and 12 months was 91.7 and 58.3% in the TPTX group, 21.1 and 7.0% in the SPTX group, and 30.0 and 0.0% in the LPTX group, respectively.

CONCLUSIONS

Although LPTX was not satisfactory as a standard procedure, both SPTX and TPTX are effective treatment methods for PHPT in patients with MEN1. The parathyroidectomy strategy should be based on intraoperative evaluation of the parathyroid glands.

Long-Term Surveillance of Treated Hyperparathyroidism for Multiple Endocrine Neoplasia Type 1: Recurrence or Hypoparathyroidism?

BACKGROUND

Primary hyperparathyroidism (HPT) in multiple endocrine neoplasia type 1 (MEN1) is surgically treated with either a subtotal parathyroidectomy removing 3 or 3,5 glands (SPX), less than 3 glands (LSPX), or a total parathyroidectomy with autotransplantation (TPX). Previous studies with shorter follow-up have shown that LSPX and SPX are associated with recurrent HPT, and TPX with hypocalcemia and substitution therapy. We examined the situation after long-term follow-up (median 20,6 years).

METHODS

Sixty-nine patients with MEN1 HPT underwent 110 operations, the first operation being 31 LSPX, 30 SPX, and 8 TPX. Thirty patients underwent reoperative surgery in median 120 months later, as completion to TPX (n = 12), completion of LSPX to SPX (n = 9), extirpation of single glands (n = 3) still resulting in LSPX, and resection of forearm grafts (n = 3). Nine patients underwent a second, and 2 a third reoperation. In 24 patients genetic testing confirmed MEN1, and in the remaining heredity and phenotype led to the diagnosis.

RESULTS

TPX had higher risk for hypoparathyroidism necessitating substitution therapy, at latest follow-up 50%, compared to SPX (16% after 3-6 months; none at latest follow-up). Recurrent HPT was common after LSPX, leading to 24 reoperations in 17 patients. No need for substitution therapy after SPX indicated forthcoming recurrent disease. Not having hypocalcemia in the postoperative period and less radical surgery than TPX were significantly associated to risk for recurrence. Further, mutation in exon 3 in the MEN1 gene may eventually be linked to risk of recurrence.

CONCLUSION

LSPX is highly associated with recurrence and TPX with continuous hypoparathyroidism, also after long-term follow-up. SPX should be the chosen method in the majority of patients with MEN1 HPT.

MEN1, MEN4, and Carney Complex: Pathology and Molecular Genetics

Pituitary adenomas are a common feature of a subset of endocrine neoplasia syndromes, which have otherwise highly variable disease manifestations. We provide here a review of the clinical features and human molecular genetics of multiple endocrine neoplasia (MEN) type 1 and 4 (MEN1 and MEN4, respectively) and Carney complex (CNC). MEN1, MEN4, and CNC are hereditary autosomal dominant syndromes that can present with pituitary adenomas. MEN1 is caused by inactivating mutations in the MEN1 gene, whose product menin is involved in multiple intracellular pathways contributing to transcriptional control and cell proliferation. MEN1 clinical features include primary hyperparathyroidism, pancreatic neuroendocrine tumours and prolactinomas as well as other pituitary adenomas. A subset of patients with pituitary adenomas and other MEN1 features have mutations in the CDKN1B gene; their disease has been called MEN4. Inactivating mutations in the type 1α regulatory subunit of protein kinase A (PKA; the PRKAR1A gene), that lead to dysregulation and activation of the PKA pathway, are the main genetic cause of CNC, which is clinically characterised by primary pigmented nodular adrenocortical disease, spotty skin pigmentation (lentigines), cardiac and other myxomas and acromegaly due to somatotropinomas or somatotrope hyperplasia.

Hereditary hyperparathyroidism--a consensus report of the European Society of Endocrine Surgeons (ESES)

BACKGROUND

Hereditary hyperparathyroidism has been reported to occur in 5-10 % of cases of primary hyperparathyroidism in the context of multiple endocrine neoplasia (MEN) types 1, 2A and 4; hyperparathyroidism-jaw tumour (HPT-JT); familial isolated hyperparathyroidism (FIHPT); familial hypocalciuric hypercalcaemia (FHH); neonatal severe hyperparathyroidism (NSHPT) and autosomal dominant moderate hyperparathyroidism (ADMH). This paper aims to review the controversies in the main genetic, clinical and pathological features and surgical management of hereditary hyperparathyroidism.

METHODS

A peer review literature analysis on hereditary hyperparathyroidism was carried out and analyzed in an evidence-based perspective. Results were discussed at the 2015 Workshop of the European Society of Endocrine Surgeons devoted to hyperparathyroidism due to multiple gland disease.

RESULTS

Literature reports scarcity of prospective randomized studies; thus, a low level of evidence may be achieved.

CONCLUSIONS

Hereditary hyperparathyroidism typically presents at an earlier age than the sporadic variants. Gene penetrance and expressivity varies. Parathyroid multiple gland involvement is common, but in some variants, it may occur metachronously often with long disease-free intervals, simulating a single-gland involvement. Bilateral neck exploration with subtotal parathyroidectomy or total parathyroidectomy + autotransplantation should be performed, especially in MEN 1, in order to decrease the persistent and recurrent hyperparathyroidism rates; in some variants (MEN 2A, HPT-JT), limited parathyroidectomy can achieve long-term normocalcemia. In FHH, surgery is contraindicated; in NSHPT, urgent total parathyroidectomy is required. In FIHPT, MEN 4 and ADMH, a tailored case-specific approach is recommended.

Value of Prophylactic Cervical Thymectomy in Parathyroid Hyperplasia

BACKGROUND

In parathyroid hyperplasia (HPT), parathyroid glands within the cervical thymus are a cause for recurrence. As a result of differences in pathophysiology, variable practice patterns exist regarding performing bilateral cervical thymectomy (BCT) in primary hyperplasia versus hyperplasia from renal failure or familial disease. The objective of this study was to capture patients where thymic tissue was found with subtotal parathyroidectomy (PTX) and intended BCT, identify number of thymic supernumerary glands (SNGs), and determine overall cure rate.

METHODS

Retrospective review of patients with four-gland exploration and intended BCT for HPT from 2000 to 2013 was performed. Identification of thymic tissue and SNGs were determined by operative/pathology reports. Univariate analysis identified differences in cure rate for patients undergoing subtotal PTX with or without BCT.

RESULTS

Thymic tissue was found in 52 % of 328 primary HPT (19 % unilateral, 33 % bilateral), 77 % of 128 renal HPT (28 % unilateral, 49 % bilateral), and 100 % of familial HPT (24 % unilateral, 76 % bilateral) patients. Nine percent of primary, 18 % of renal, and 10 % of familial HPT patients had SNGs within thymectomy specimens. Cure rates of primary HPT patients with BCT were 99 % compared to 94 % in subtotal PTX alone. Renal HPT cure rates were 94 % with BCT compared to 89 % without BCT.

CONCLUSIONS

Renal HPT patients benefited most in cure when thymectomy was performed. Although the rate of SNGs found in primary HPT was lower than renal HPT, the cure rate mimicked the pattern in renal disease. Furthermore, the incidences of SNGs in primary and familial HPT were similar. On the basis of these data, we advocate that BCT be considered in primary HPT when thymic tissue is readily identified.

Outcomes after subtotal parathyroidectomy for primary hyperparathyroidism due to hyperplasia: significance of whole vs. partial gland remnant

INTRODUCTION

Primary hyperparathyroidism (PHPT) due to multigland hyperplasia is managed by subtotal parathyroidectomy (sPTX), with a partial gland left in situ. However, smaller, hyperplastic glands may be encountered intraoperatively, and it is unclear if leaving an intact gland is an equivalent alternative. This study evaluates the rates of permanent hypoparathyroidism and cure of PHPT patients with four-gland hyperplasia that were left with either a whole gland remnant (WGR) or a partial gland remnant (PGR) after sPTX.

METHODS

We reviewed the outcomes of PHPT patients with hyperplasia who underwent sPTX at an academic institution. Surgeon intraoperative judgment determined remnant size (a WGR vs. a PGR).

RESULTS

Between 2002 and 2013, 172 patients underwent sPTX for PHPT. There were 108 patients (62.8%) who had a WGR. Another 64 patients (37.2%) had a PGR. Mean age was 60 ± 14 years. There were 82.6% female patients. Cases with positive family history for PHPT were more likely to have a PGR (12.5 vs. 3.7%; p = 0.03). Patients had similar preoperative and postoperative laboratories. Individuals with a PGR tended to have larger glands encountered by surgeons intraoperatively (525 ± 1,308 vs. 280 ± 341 mg; p = 0.02). One patient with a WGR developed permanent hypocalcemia. Overall, the cure rate was 97.1%. A mean of 29 ± 28.7 months follow-up revealed a recurrence rate of 5.2%. Disease persistence and recurrence rates were similar in patients.

CONCLUSION

PHPT due to hyperplasia is managed by sPTX, leaving WGR without increased rates of disease persistence/recurrence. Patients without family history for hyperparathyroidism and those with smaller glands may be the best candidates for this approach.

Familial Endocrine Syndromes

Endocrine tumors may present as sporadic events or as part of familial endocrine syndromes. Familial endocrine syndromes (or inherited tumor/neoplasm syndromes) are characterized by multiple tumors in multiple organs. Some morphologic findings in endocrine tumor histopathology may prompt the possibility of familial endocrine syndromes, and these recognized histologic features may lead to further molecular genetic evaluation of the patient and family members. Subsequent evaluation for these syndromes in asymptomatic patients and family members may then be performed by genetic screening.

Multiple endocrine neoplasia type 1 (MEN1) and type 4 (MEN4)

Multiple endocrine neoplasia (MEN) is characterized by the occurrence of tumors involving two or more endocrine glands within a single patient. Four major forms of MEN, which are autosomal dominant disorders, are recognized and referred to as: MEN type 1 (MEN1), due to menin mutations; MEN2 (previously MEN2A) due to mutations of a tyrosine kinase receptor encoded by the rearranged during transfection (RET) protoncogene; MEN3 (previously MEN2B) due to RET mutations; and MEN4 due to cyclin-dependent kinase inhibitor (CDNK1B) mutations. Each MEN type is associated with the occurrence of specific tumors. Thus, MEN1 is characterized by the occurrence of parathyroid, pancreatic islet and anterior pituitary tumors; MEN2 is characterized by the occurrence of medullary thyroid carcinoma (MTC) in association with phaeochromocytoma and parathyroid tumors; MEN3 is characterized by the occurrence of MTC and phaeochromocytoma in association with a marfanoid habitus, mucosal neuromas, medullated corneal fibers and intestinal autonomic ganglion dysfunction, leading to megacolon; and MEN4, which is also referred to as MENX, is characterized by the occurrence of parathyroid and anterior pituitary tumors in possible association with tumors of the adrenals, kidneys, and reproductive organs. This review will focus on the clinical and molecular details of the MEN1 and MEN4 syndromes. The gene causing MEN1 is located on chromosome 11q13, and encodes a 610 amino-acid protein, menin, which has functions in cell division, genome stability, and transcription regulation. Menin, which acts as scaffold protein, may increase or decrease gene expression by epigenetic regulation of gene expression via histone methylation. Thus, menin by forming a subunit of the mixed lineage leukemia (MLL) complexes that trimethylate histone H3 at lysine 4 (H3K4), facilitates activation of transcriptional activity in target genes such as cyclin-dependent kinase (CDK) inhibitors; and by interacting with the suppressor of variegation 3-9 homolog family protein (SUV39H1) to mediate H3K methylation, thereby silencing transcriptional activity of target genes. MEN1-associated tumors harbor germline and somatic mutations, consistent with Knudson's two-hit hypothesis. Genetic diagnosis to identify individuals with germline MEN1 mutations has facilitated appropriate targeting of clinical, biochemical and radiological screening for this high risk group of patients for whom earlier implementation of treatments can then be considered. MEN4 is caused by heterozygous mutations of CDNK1B which encodes the 196 amino-acid CDK1 p27Kip1, which is activated by H3K4 methylation.

Translational research in endocrine surgery

This article reviews translational research in endocrine surgery, with a focus on disorders of the thyroid, parathyroids, adrenals, and endocrine pancreas. Discovery of genes responsible for heritable endocrine cancer syndromes has increased knowledge of the causes and mechanisms of endocrine cancer and has refined surgical treatment options. Knowledge of mutations in sporadic cancer has led to rapid progress in small-molecule kinase inhibitor strategies. These breakthroughs and their influence on current therapy are discussed to provide surgeons with an overview of the basic science research currently creating new clinical treatments and improving patient care.

Genetic and clinical features of multiple endocrine neoplasia types 1 and 2

Multiple endocrine neoplasia (MEN) are clinical inherited syndromes affecting different endocrine glands. Three different patterns of MEN syndromes can occur (MEN 1, MEN 2A, and MEN 2B). MEN syndromes are very rare, affect all ages and both sexes are equally affected. MEN 1 is characterized by the neoplastic transformation of the parathyroid glands, pancreatic islets, anterior pituitary, and gastrointestinal tract. Heterozygous MEN 1 germline mutations have been detected in about 70–80% of patients with MEN 1. The mutations are scattered throughout the entire genomic sequence of the gene. MEN 1 patients are characterized by variable clinical features, thus suggesting the lack of a genotype-phenotype correlation. Therapeutical approaches are different according to the different endocrinopathies. The prognosis is generally good if adequate treatment is provided. In MEN 2 syndromes, the medullary thyroid cancer (MTC) is almost invariably present and can be associated with pheochromocytoma (PHEO) and/or multiple adenomatosis of parathyroid glands with hyperparathyroidism (PHPT). The different combination of the endocrine neoplasia gives origin to 3 syndromes: MEN 2A, MEN 2B, and FMTC. The clinical course of MTC varies considerably in the three syndromes. It is very aggressive in MEN 2B, almost indolent in the majority of patients with FMTC and with variable degrees of aggressiveness in patients with MEN 2A. Activating germline point mutations of the RET protooncogene are present in 98% of MEN 2 families. A strong genotype-phenotype correlation has been observed and a specific RET mutation may be responsible for a more or less aggressive clinical course. The treatment of choice for primary MTC is total thyroidectomy with central neck lymph nodes dissection. Nevertheless, 30% of MTC patients, especially in MEN 2B and 2A, are not cured by surgery. Recently, developed molecular therapeutics that target the RET pathway have shown very promising activity in clinical trials of patients with advanced MTC. MEN 2 prognosis is strictly dependent on the MTC aggressiveness and thus on the success of the initial treatment.

Clinical practice guidelines for multiple endocrine neoplasia type 1 (MEN1)

OBJECTIVE

The aim was to provide guidelines for evaluation, treatment, and genetic testing for multiple endocrine neoplasia type 1 (MEN1).

PARTICIPANTS

The group, which comprised 10 experts, including physicians, surgeons, and geneticists from international centers, received no corporate funding or remuneration.

PROCESS

Guidelines were developed by reviews of peer-reviewed publications; a draft was prepared, reviewed, and rigorously revised at several stages; and agreed-upon revisions were incorporated.

CONCLUSIONS

MEN1 is an autosomal dominant disorder that is due to mutations in the tumor suppressor gene MEN1, which encodes a 610-amino acid protein, menin. Thus, the finding of MEN1 in a patient has important implications for family members because first-degree relatives have a 50% risk of developing the disease and can often be identified by MEN1 mutational analysis. MEN1 is characterized by the occurrence of parathyroid, pancreatic islet, and anterior pituitary tumors. Some patients may also develop carcinoid tumors, adrenocortical tumors, meningiomas, facial angiofibromas, collagenomas, and lipomas. Patients with MEN1 have a decreased life expectancy, and the outcomes of current treatments, which are generally similar to those for the respective tumors occurring in non-MEN1 patients, are not as successful because of multiple tumors, which may be larger, more aggressive, and resistant to treatment, and the concurrence of metastases. The prognosis for MEN1 patients might be improved by presymptomatic tumor detection and undertaking treatment specific for MEN1 tumors. Thus, it is recommended that MEN1 patients and their families should be cared for by multidisciplinary teams comprising relevant specialists with experience in the diagnosis and treatment of patients with endocrine tumors.

Primary hyperparathyroidism in multiple endocrine neoplasia type 1: when to perform surgery?

Primary hyperparathyroidism is a common endocrinological disorder. In rare circumstances, it is associated with familial syndromes, such as multiple endocrine neoplasia type 1. This syndrome is caused by a germline mutation in the multiple endocrine neoplasia type 1 gene encoding the tumor-suppressor protein menin. Usually, primary hyperparathyroidism is the initial clinical expression in carriers of multiple endocrine neoplasia type 1 mutations, occurring in more than 90% of patients and appearing at a young age (20-25 years). Multiple endocrine neoplasia type 1/primary hyperparathyroidism is generally accompanied by multiglandular disease, clinically manifesting with hypercalcemia, although it can remain asymptomatic for a long time and consequently not always be recognized early. Surgery is the recommended treatment. The goal of this short review is to discuss the timing of surgery in patients when primary hyperparathyroidism is associated with multiple endocrine neoplasia type 1.

Total parathyroidectomy in a large cohort of cases with hyperparathyroidism associated with multiple endocrine neoplasia type 1: experience from a single academic center

Most cases of sporadic primary hyperparathyroidism present disturbances in a single parathyroid gland and the surgery of choice is adenomectomy. Conversely, hyperparathyroidism associated with multiple endocrine neoplasia type 1 (hyperparathyroidism/multiple endocrine neoplasia type 1) is an asynchronic, asymmetrical multiglandular disease and it is surgically approached by either subtotal parathyroidectomy or total parathyroidectomy followed by parathyroid auto-implant to the forearm. In skilful hands, the efficacy of both approaches is similar and both should be complemented by prophylactic thymectomy. In a single academic center, 83 cases of hyperparathyroidism/ multiple endocrine neoplasia type 1 were operated on from 1987 to 2010 and our first surgical choice was total parathyroidectomy followed by parathyroid auto-implant to the non-dominant forearm and, since 1997, associated transcervical thymectomy to prevent thymic carcinoid. Overall, 40% of patients were given calcium replacement (mean intake 1.6 g/day) during the first months after surgery, and this fell to 28% in patients with longer follow-up. These findings indicate that several months may be needed in order to achieve a proper secretion by the parathyroid auto-implant. Hyperparathyroidism recurrence was observed in up to 15% of cases several years after the initial surgery. Thus, long-term follow-up is recommended for such cases. We conclude that, despite a tendency to subtotal parathyroidectomy worldwide, total parathyroidectomy followed by parathyroid auto-implant is a valid surgical option to treat hyperparathyroidism/multiple endocrine neoplasia type 1. Larger comparative systematic studies are needed to define the best surgical approach to hyperparathyroidism/multiple endocrine neoplasia type 1.

Primary hyperparathyroidism in patients with multiple endocrine neoplasia type 1

Primary hyperparathyroidism may occur as a part of an inherited syndrome in a combination with pancreatic endocrine tumours and/or pituitary adenoma, which is classified as Multiple Endocrine Neoplasia type 1 (MEN-1). This syndrome is caused by a germline mutation in MEN-1 gene encoding a tumour-suppressor protein, menin. Primary hyperparathyroidism is the most frequent clinical presentation of MEN-1, which usually appears in the second decade of life as an asymptomatic hypercalcemia and progresses through the next decades. The most frequent clinical presentation of MEN-1-associated primary hyperparathyroidism is bone demineralisation and recurrent kidney stones rarely followed by chronic kidney disease. The aim of this paper is to present the pathomechanism, screening procedures, diagnosis, and management of primary hyperparathyroidism in the MEN-1 syndrome. It also summarises the recent advances in the pharmacological therapy with a new group of drugs-calcimimetics.

Application of genetic testing to define the surgical approach in a sporadic case of multiple endocrine neoplasia type 1

We report the use of a genetic test for therapeutic decision making in a case of primary hyperparathyroidism associated with Cushing's disease (CD). A 20-year-old woman was evaluated for gradual weight gain, asthenia, muscle pain, and hypertension. Biochemical and radiologic tests confirmed CD and she underwent transsphenoidal surgery. Immunohistochemistry of the microadenoma was positive for adrenocorticotropic hormone (ACTH). On follow-up, hypercalcemia with high parathyroid hormone (PTH) levels was detected, associated with nephrolithiasis and low bone mineral density in the spine and hip. Parathyroid scintigraphy showed tracer uptake in the inferior region of the left thyroid lobe, and cervical ultrasound showed a heterogeneous nodule in the same area, suggestive of a parathyroid adenoma (PA). Genetic testing detected mutation in the MEN 1 gene and total parathyroidectomy with the implantation of a fragment of one gland in the forearm was performed. Pathology showed a PA and 3 normal parathyroid glands, without hyperplasia, despite the diagnosis of MEN 1. This case illustrates the role of genetic testing in defining the therapeutic approach for sporadic MEN 1.