Surgical management of MEN-1 and -2: state of the art

Evaluation and Surgical Management of Multiple Endocrine Neoplasias

Multiple endocrine neoplasia (MEN) syndromes are rare autosomal dominant diseases that are associated with a mixture of both endocrine and non-endocrine tumors. Traditionally, there are 2 types of MEN that have unique clinical associations: MEN 1 (parathyroid hyperplasia, pancreatic neuroendocrine tumors, and pituitary tumors) and MEN 2 (medullary thyroid carcinoma and pheochromocytoma), which is further classified into MEN 2A (adds parathyroid adenomas) and 2B (adds ganglioneuromas and marfanoid habitus). Many of the endocrine tumors are resected surgically, and the pre, intra, and postoperative management strategies used must take into account the high recurrence rates asscioated with MEN tumors.

Challenges in genetic screening for inherited endocrinopathy affecting the thyroid, parathyroid and adrenal glands in Singapore

Significant progress has been made in the understand-ing of many human diseases, especially cancers, which has contributed to improved and increased survival. The Human Genome Project and The Cancer Genome Atlas project brought about a new era, with an understanding of inherited diseases at a molecular level, which subsequently facilitated the option of precision medicine. Precision medicine has helped tailor treatment decisions at an individual level, for instance in terms of surgical treatments or targeted therapies in advanced diseases. Despite the increasing advances in genetic-lead precision medicine, this has not translated into increasing uptake among patients. Reasons for this may be potential knowledge gaps among clinicians; on reasons for poor uptake of genetic testing such as for cultural, religious or personal beliefs; and on financial implications such as lack of support from insurance companies. In this review, we look at the current scenario of genetic screening for common inherited endocrine conditions affecting the thyroid, parathyroid and adrenal glands in Singapore, and the implications associated with it.

The role of prophylactic parathyroidectomy during thyroidectomy for MTC in patients with MEN2A syndrome

AIM

To define the role of prophylactic parathyroidectomy in the surgical treatment of medullary thyroid carcinoma (MTC) in multiple endocrine neoplasia type IIa (MEN2A) syndrome through a literature review.

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.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

Nonfunctional pancreatic endocrine tumor in the peripancreatic region in a Chinese patient with multiple endocrine neoplasia type 1

Nonfunctional pancreatic neuroendocrine tumors (NF-pNETs) in patients with multiple endocrine neoplasia type 1 (MEN1), which results from a mutation in the MEN1 gene, are commonly small, multiple tumors located in the pancreatic head and inside the pancreatic parenchyma. We herein describe a 35-year-old woman with bone pain and a 7-year history of a prolactinoma. She was clinically diagnosed with MEN1 based on the presence of the prolactinoma and parathyroid hyperplasia. Abdominal computed tomography revealed a 5-cm mass close to the splenic hilum. This soft tissue tumor, which was located outside the pancreatic parenchyma and the tissue origin of which could not be identified preoperatively, was found to be connected to the pancreatic tail. After resection, histological examination revealed a well-differentiated neuroendocrine tumor of pancreatic origin. Genetic testing revealed a heterozygous transition mutation of guanine to adenine at the coding nucleotide 133 in exon 2 (c.133G>A), resulting in an amino acid substitution of glutamic acid with lysine (E45K) in the MEN1 gene. This patient with MEN1 presented with a clinical condition involving a single non-metastatic NF-pNET located outside the pancreatic parenchyma with a missense mutation in the MEN1 gene, which could easily have been misdiagnosed as an accessory spleen.

Utility of intraoperative parathyroid hormone monitoring in patients with multiple endocrine neoplasia type 1-associated primary hyperparathyroidism undergoing initial parathyroidectomy

BACKGROUND

Intraoperative parathyroid hormone monitoring (IOPTH) is a widely used adjunct for primary hyperparathyroidism (pHPT). However, the benefit of IOPTH in familial pHPT, such as in multiple endocrine neoplasia type I (MEN1), remains unclear.

METHODS

We performed a retrospective analysis of 52 patients with MEN1-associated pHPT undergoing initial parathyroidectomy with IOPTH monitoring at our institution. Parathyroid hormone (PTH) levels were measured before skin incision and 10 min after resection of the last parathyroid gland. Variables analyzed included percent drop of PTH from baseline and the final PTH level compared to the normal reference range (RR).

RESULTS

A total of 52 patients underwent initial subtotal parathyroidectomy with IOPTH. An IOPTH decrease cutoff of ≥75 % from baseline had the highest biochemical cure rate (87 %). In the remaining 13 % who met this cutoff, all had persistent pHPT, with ≥90 % drop of PTH from baseline. The remaining patients, who did not meet the ≥75 % cutoff, were cured. Follow-up was available for three of four patients with final IOPTH levels above the RR: one had persistent pHPT, two had hypoparathyroidism (50 %). When a postresection PTH level was within the RR, 88 % of patients were cured. While considered cured from pHPT, 7 % of patients in this group developed permanent hypoparathyroidism. When the final PTH level dropped below the RR, 28 % developed permanent hypoparathyroidism.

CONCLUSIONS

A cutoff in IOPTH decrease of ≥75 % from baseline has the highest biochemically cure rate in patients with pHPT associated with MEN1. However, a 75 % cutoff in IOPTH decrease does not exclude persistent pHPT. The absolute IOPTH value does not accurately predict postoperative hypoparathyroidism.

Diagnosis and surgical treatment of multiple endocrine neoplasia type 2A

BACKGROUND

This study aims to introduce the diagnosis and surgical treatment of the rare disease multiple endocrine neoplasia type 2A (MEN 2A).

METHODS

Thirteen cases of MEN 2A were diagnosed as medullary thyroid carcinoma (MTC) and pheochromocytoma by biochemical tests and imaging examination. They were treated by bilateral adrenal tumor excision or laparoscopic surgery.

RESULTS

Nine patients were treated by bilateral adrenal tumor excision and the remaining four were treated by laparoscopic surgery for pheochromocytoma. Ten patients were treated by total thyroidectomy and bilateral lymph nodes dissection and the remaining three were treated by unilateral thyroidectomy for MTC. Up to now, three patients have died of MTC distant metastasis.

CONCLUSIONS

We confirmed that MEN 2A can be diagnosed by biochemical tests and imaging examination when genetic testing is not available. Surgical excision is the predominant way to treat MEN 2A; pheochromocytoma should be excised at first when pheochromocytoma and MTC occur simultaneously.

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.

Multiple Endocrine Neoplasia

Multiple endocrine neoplasia (MEN) is an array of tumors found in various endocrine glands throughout the human body. A wide spectrum of clinical manifestations accompanies this syndrome. The complexities of the glandular function and subtle development of symptoms can cause the diagnosis to be missed, and individuals with MEN can be an enigma to the care team. Appropriate differential diagnosis and assessment are critical for these individuals to receive optimal care. An interprofessional team of health care providers, including an endocrinologist and an advanced practice endocrine nurse, must work in concert to orchestrate a plan of care across the continuum. Those specialized nurses who encounter individuals with MEN in a critical care setting are positioned to support the patient, the family, and the care team through this maze of multiple endocrinopathies and tumors.

A differential diagnosis of inherited endocrine tumors and their tumor counterparts

Inherited endocrine tumors have been increasingly recognized in clinical practice, although some difficulties still exist in differentiating these conditions from their sporadic endocrine tumor counterparts. Here, we list the 12 main topics that could add helpful information and clues for performing an early differential diagnosis to distinguish between these conditions. The early diagnosis of patients with inherited endocrine tumors may be performed either clinically or by mutation analysis in at-risk individuals. Early detection usually has a large impact in tumor management, allowing preventive clinical or surgical therapy in most cases. Advice for the clinical and surgical management of inherited endocrine tumors is also discussed. In addition, recent clinical and genetic advances for 17 different forms of inherited endocrine tumors are briefly reviewed.

Lymph nodes metastasis and recurrences justify an aggressive treatment of gastrinoma

In the current study, short- and long-term outcomes after aggressive surgical treatment for gastrinoma were evaluated. From August 1990 to August 2009, 20 patients diagnosed with Zollinger Ellison syndrome were reviewed. Eleven pancreaticoduodenectomies, three total pancreatectomies, four lymph node dissections, four enucleations and two palliative procedures were performed. Four (27.8 %) patients had disease associated with MEN1 syndrome, 13 (72.2 %) had sporadic gastrinomas (SG) and 3 had disease of unknown primary origin. No in-hospital mortality was observed. After radical resection, lymph node metastasis was present in 82 % of the cases. Eight percent of patients who underwent radical resection developed recurrence compared with 100 % of those who underwent enucleoresection (p = 0.03). Average time to recurrence in patients with sporadic gastrinoma was 66.7 months (confidence interval (CI) 62.9-70.5) in those treated with enucloeresection compared to 181.1 months (CI 124.3-237.8) in the radical resection group (p = 0.007). One recurrence was observed in the MEN1 group. Based on post-operative mortality, recurrence and lymph node metastasis, our data suggest that patients with gastrinoma should undergo abdominal exploration with aggressive resection of the primary tumour and regional lymph nodes in place of conservative treatment.

Non-invasive prenatal diagnosis of multiple endocrine neoplasia type 2A using COLD-PCR combined with HRM genotyping analysis from maternal serum

The multiple endocrine neoplasia type 2A (MEN2A) is a monogenic disorder characterized by an autosomal dominant pattern of inheritance which is characterized by high risk of medullary thyroid carcinoma in all mutation carriers. Although this disorder is classified as a rare disease, the patients affected have a low life quality and a very expensive and continuous treatment. At present, MEN2A is diagnosed by gene sequencing after birth, thus trying to start an early treatment and by reduction of morbidity and mortality. We first evaluated the presence of MEN2A mutation (C634Y) in serum of 25 patients, previously diagnosed by sequencing in peripheral blood leucocytes, using HRM genotyping analysis. In a second step, we used a COLD-PCR approach followed by HRM genotyping analysis for non-invasive prenatal diagnosis of a pregnant woman carrying a fetus with a C634Y mutation. HRM analysis revealed differences in melting curve shapes that correlated with patients diagnosed for MEN2A by gene sequencing analysis with 100% accuracy. Moreover, the pregnant woman carrying the fetus with the C634Y mutation revealed a melting curve shape in agreement with the positive controls in the COLD-PCR study. The mutation was confirmed by sequencing of the COLD-PCR amplification product. In conclusion, we have established a HRM analysis in serum samples as a new primary diagnosis method suitable for the detection of C634Y mutations in MEN2A patients. Simultaneously, we have applied the increase of sensitivity of COLD-PCR assay approach combined with HRM analysis for the non-invasive prenatal diagnosis of C634Y fetal mutations using pregnant women serum.

Preoperative localizing studies for initial parathyroidectomy in MEN1 syndrome: is there any benefit?

BACKGROUND

The objective of the present study was to evaluate the utility of preoperative localizing studies in patients with MEN1 undergoing initial bilateral neck exploration (BNE) and parathyroidectomy for pHPT.

METHODS

We performed a retrospective analysis of patients diagnosed with MEN1 who underwent initial parathyroidectomy between December 1993 and December 2010. Results of preoperative localizing studies were compared with intraoperative findings and outcome.

RESULTS

Sixty patients with MEN1 (32 females and 28 males) underwent initial subtotal parathyroidectomy. The median age at the time of surgery was 33 years (range: 13-78 years). Fifty-three patients had one or more positive localizing study results. Neck ultrasonography, sestamibi scan, parathyroid protocol computed tomography scan, and neck and mediastinum magnetic resonance imaging were performed in 93, 91, 32, and 19% of patients, respectively. Fifty-three patients (88%) had cervical thymectomy. Twenty patients had 24 ectopic parathyroid glands; 18 glands were in the thymus (75%). Preoperative localizing studies identified 9 of 24 ectopic parathyroid glands (38%), including 4 ectopic glands outside the thymus in 4 patients (7%); 3 were detected by ultrasonography. There were no supernumerary glands identified on preoperative localizing studies.

CONCLUSIONS

In patients with MEN1, preoperative localizing studies identified a subset of ectopic glands (38%). Preoperative localizing studies may alter the operative approach in 7% of patients. Ultrasonography can detect most ectopic parathyroid glands outside thymus. This suggests that routine preoperative localizing studies to identify ectopic and supernumerary enlarged parathyroid glands is not useful in the majority of patients with MEN1 undergoing bilateral neck exploration and subtotal parathyroidectomy with cervical thymectomy.

Surgical management of pancreatico-duodenal tumors in multiple endocrine neoplasia syndrome type 1

Pancreatico-duodenal tumors are the second most common endocrinopathy in multiple endocrine neoplasia syndrome type 1, and have a pronounced effect on life expectancy as the principal cause of disease-related death. Previous discussions about surgical management have focused mainly on syndromes of hormone excess and, in particular, the management of multiple endocrine neoplasia syndrome type 1-related Zollinger-Ellison syndrome. Since hormonal syndromes tend to occur late and indicate the presence of metastases, screening with biochemical markers and endoscopic ultrasound is recommended for early detection of pancreatico-duodenal tumors, and with early surgery before metastases have developed. Surgery is recommended in patients with or without hormonal syndromes in the absence of disseminated liver metastases. The suggested operation includes distal 80% subtotal pancreatic resection together with enucleation of tumors in the head of the pancreas, and in cases with Zollinger-Ellison syndrome, excision of duodenal gastrinomas together with clearance of regional lymph node metastases. This strategy, with early and aggressive surgery before metastases have developed, is believed to reduce the risks for tumor recurrence and malignant progression.

Multiple endocrine neoplasia type 1- presenting multiple lipomas and hypoglycemia onset

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1), also called Wermer syndrome, is an autosomal dominant disorder characterized by tumors of the parathyroid glands, the anterior pituitary, and the endocrine pancreas.

CASE REPORT

Here, we report a case of MEN1. Our patient was a 44-year-old woman who manifested typical features of MEN1, including insulinoma, pituitary tumors, and parathyroidoma, and exhibited multiple lipomas and a gastrinoma with duodenal ulcers. She was admitted to our hospital because of recurrent massive bleeding of the upper gastrointestinal tract and hypoglycemia. The first operation for pituitary tumors was performed when she was 40 years old. According to these examinations and her clinical course, the patient was diagnosed with insulinoma and gastrinoma. She subsequently underwent surgery for the pancreatic tumors. The majority of these tumor cells were immunohistochemically positive for insulin and negative for glucagon.

CONCLUSIONS

This case suggests that multiple lipomas, insulinoma and gastrinoma may provide clues for a diagnosis of MEN1.

Multiple endocrine neoplasia 2a presenting with pheochromocytoma and pituitary macroadenoma

Multiple Endocrine Neoplasia type 2A (MEN-2a) is a rare disease associated with tumors of endocrine organs. Presentation most commonly is with medullary thyroid cancer and infrequently with other complaints. Pituitary adenoma has been seen coincidentally with this disease very rarely. Presented is a case of coincident MEN-2a with a symptomatic pituitary adenoma and an asymptomatic pheochromocytoma. A brief review is also provided.

Multiple endocrine neoplasia 2: providing care for the family

Multiple endocrine neoplasia 2 (MEN2) is a hereditary syndrome associated with medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism. Unfortunately, a diagnosis of MEN2 often is delayed until after the patient has developed an advanced MEN2-related tumor. Nurses should be familiar with hallmark signs of this syndrome to facilitate an early diagnosis and appropriately refer families for genetic assessment and, ultimately, develop a long-term plan for early detection and intervention for all family members at risk for developing MEN2.

Multiple endocrine neoplasia 1: providing care for the family

Multiple endocrine neoplasia 1 (MEN1) is a hereditary syndrome associated with a number of endocrine and nonendocrine tumors. Unfortunately, a diagnosis of MEN1 often is delayed until after the patient has developed an advanced or second MEN1-related tumor. Nurses need to be familiar with hallmark signs of this syndrome to facilitate an early diagnosis and appropriately refer families for genetic assessment and, ultimately, develop a long-term plan for early detection and intervention for all family members at risk for MEN1.