Multiple endocrine neoplasia type 2

Incidental detection of multiple endocrine neoplasia and medullary thyroid carcinoma before starting GLP-1 agonist: A case report

A man, in his 30s, with a history of obesity and hypothyroidism planned to begin taking a new Glucagon-like peptide-1 (GLP-1) agonist for weight loss. As these medications have been associated with C-cell hyperplasia, a calcitonin level was checked as evaluation prior to starting the drug. This returned at 131 pg/mL (upper limit of normal<10 pg/mL), and a subsequent carcinoembryonic antigen was 5.2 ng/mL (ref<3 ng/mL). Thyroid ultrasound was performed and demonstrated bilateral subcentimeter nodules. After total thyroidectomy, final pathology demonstrated bilateral 0.8 cm medullary thyroid carcinoma. Genetic testing revealed a NM_020975.6: c.1826G > A; p.Cys609Tyr. germline RET mutation, confirming the diagnosis of multiple endocrine neoplasia 2 syndrome. The patient recovered well from treatment. His first-degree relatives also underwent genetic testing. This case represents a surprising diagnosis of familial multiple endocrine neoplasia 2A prior to starting a Glucagon-like peptide-1 agonist.

Primary Hyperparathyroidism in Young Adult Patients

BACKGROUND

Primary hyperparathyroidism (PHPT) affects 2% of Americans over 55 years of age, and is less common in younger patients. Pediatric PHPT patients have higher rates of multigland disease (MGD). We studied young adult patients to determine whether they have similarly elevated rates of MGD and would benefit from routine bilateral neck exploration.

METHODS

Retrospective chart review was performed on patients who underwent parathyroidectomy for PHPT (2000-2019). Cohorts were defined by age: Group A (18-40 years) and Group B (> 40 years). Univariate and multivariate logistic regression analyses were performed.

RESULTS

Of 3889 patients with PHPT, 9.1% (n = 352) were included in Group A. On multivariate analysis, multiple endocrine neoplasia (odds ratio [OR] 6.3, 95% confidence interval [CI] 3.1-12.7), male sex (OR 1.3, 95% CI 1.0-1.5), family history of PHPT (OR 2.7, 95% CI 1.6-4.8), prior parathyroidectomy (OR 2.2, 95% CI 1.6-3.0), and non-localizing imaging (OR 1.8, 95% CI 1.5-2.1) were associated with MGD; younger age was not an independent risk factor. In patients with sporadic PHPT (n = 3833), family history was most strongly associated with MGD (OR 4.0, 95% CI 2.2-7.3).

CONCLUSIONS

In our population of patients with sporadic PHPT, a positive family history of PHPT was strongly associated with MGD; additional associations were found with prior parathyroidectomy, non-localizing imaging, and male sex. Younger age was not an independent risk factor. Age alone in the absence of a family history should not raise suspicion for MGD nor determine the need for bilateral neck exploration.

Thyroid Carcinoma, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

Differentiated thyroid carcinomas is associated with an excellent prognosis. The treatment of choice for differentiated thyroid carcinoma is surgery, followed by radioactive iodine ablation (iodine-131) in select patients and thyroxine therapy in most patients. Surgery is also the main treatment for medullary thyroid carcinoma, and kinase inhibitors may be appropriate for select patients with recurrent or persistent disease that is not resectable. Anaplastic thyroid carcinoma is almost uniformly lethal, and iodine-131 imaging and radioactive iodine cannot be used. When systemic therapy is indicated, targeted therapy options are preferred. This article describes NCCN recommendations regarding management of medullary thyroid carcinoma and anaplastic thyroid carcinoma, and surgical management of differentiated thyroid carcinoma (papillary, follicular, Hürthle cell carcinoma).

MEN 2A syndrome - Multiple endocrine neoplasia with autosomal dominant transmission

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Every case essential, because MEN 2A is reported in 500–1000 families worldwide.

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This case reflects correct clinical steps in avoidance of possible complications.

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It contributes to the existing limited literature reports.

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MTC can be confirmed before macroscopic changes through evaluation of calcitonin.

Introduction

Multiple endocrine neoplasias (MEN) are rare inherited syndromes. MEN type 2 syndromes occur in 1:30000 individuals, and are reported in approximately 500–1000 families worldwide, the most frequent being MEN 2A (80%), followed by familial medullary thyroid carcinoma (15%) and MEN 2B (5%) (Marx and Wells, 2011; Dumitrache, 2012).

Case

The patient, a 20-years old with MEN 2A syndrome, which has been manifested by bilateral pheochromocytoma and medullary thyroid carcinoma. It was a familial form, having first degree relatives (mother) with pheochromocytoma. The patient underwent laparoscopic adrenalectomy on her left in 2015, laparoscopic adrenalectomy on the right in 2019 and total thyroidectomy in 2020 year. The postoperative evolution of this patient is favorable. She is satisfied with the received treatment and is being supervised by an endocrinologist, undergoing hormone replacement therapy.

Conclusions

The case demonstrates the importance of the radical approach to MEN 2A syndrome from both a therapeutic and surgical point of view.

If a pheochromocytoma is detected, adrenalectomy should be performed before thyroidectomy or other surgery to avoid intraoperative catecholamine release.

Laparoscopy is the choice of approach in surgical treatment. Limitations only arise because of technical difficulties or tumor size.

The overall risk of malignancies is not increased in patients with Hirschsprung disease

PURPOSE

Hirschsprung disease (HSCR) has previously been associated with increased risk of medullary thyroid cancer. The aim of this study was to assess the overall risk of malignancies in patients with Hirschsprung disease in a population-based cohort.

METHODS

This was a nationwide, population-based cohort study. The study exposure was HSCR and the study outcome was malignancy. The cohort included all individuals with HSCR registered in the Swedish National Patient Register between 1964 and 2013 and ten age- and sex-matched controls per patient, randomly selected from the Population Register. Data were linked with the Swedish National Cancer Register to identify individuals with malignancy diagnosis.

RESULTS

The cohort comprised 739 individuals with HSCR (565 male) and 7390 controls (5650 male). Median age of the cohort was 19 years (range 2-49). In total nine (1.2%) individuals in the exposed cohort were diagnosed with malignancies compared to 57 (0.8%) in the non-exposed cohort (p = 0.195). Median age at malignancy diagnosis was 3 years (range 0-46) in the exposed group, compared to 23 (range 0-42), p = 0.132. No cases with medullary carcinoma of the thyroid were found in this cohort.

CONCLUSIONS

There was no significant difference in risk of malignancies in the exposed group compared to the unexposed group.

Familial isolated primary hyperparathyroidism associated with germline GCM2 mutations is more aggressive and has a lesser rate of biochemical cure

BACKGROUND

Hereditary primary hyperparathyroidism may be syndromic or nonsyndromic (familial isolated hyperparathyroidism). Recently, germline activating mutations in the GCM2 gene were identified in a subset of familial isolated hyperparathyroidism. This study examined the clinical and biochemical characteristics and the treatment outcomes of GCM2 mutation-positive familial isolated hyperparathyroidism as compared to sporadic primary hyperparathyroidism.

METHODS

We performed a retrospective analysis of clinical features, parathyroid pathology, and operative outcomes in 18 patients with GCM2 germline mutations and 457 patients with sporadic primary hyperparathyroidism.

RESULTS

Age at diagnosis, sex distribution, race/ethnicity, and preoperative serum calcium concentrations were similar between the 2 groups. The preoperative serum levels of intact parathyroid hormone was greater in patients with GCM2-associated primary hyperparathyroidism (239 ± 394 vs 136 ± 113, P = .005) as were rates of multigland disease and parathyroid carcinoma in the GCM2 group (78% vs 14.3%, P < .001 and 5% vs 0%, P = .04, respectively), but the biochemical cure rate was less in the GCM2 group (86% vs 99%, P < .001).

CONCLUSION

GCM2-associated primary hyperparathyroidism patients have greater preoperative parathyroid hormone levels, a greater rate of multigland disease, a lesser rate of biochemical cure, and a substantial risk of parathyroid carcinoma. Knowledge of these clinical characteristics could optimize the surgical management of GCM2-associated familial isolated hyperparathyroidism.

Evidence-based evaluation of the thyroid nodule

This article reviews the most current literature on thyroid nodule evaluation, with particular attention to the problem of the incidentally identified thyroid nodule. Although traditional risk factors for thyroid cancer, such as age, gender, and familial syndromes, are still important, the manner in which a thyroid nodule comes to attention is of great importance these days when considering how to proceed in a workup. Most thyroid nodules today are discovered through radiologic imaging tests performed for other reasons. This article covers the key considerations that are vital in balancing the risks and benefits of thyroid nodule workup and treatment.

Clinical Presentation and Diagnosis of Neuroendocrine Tumors

Neuroendocrine tumors (NETs) are slow-growing neoplasms capable of storing and secreting different peptides and neuroamines. Some of these substances cause specific symptom complexes, whereas others are silent. They usually have episodic expression, and the diagnosis is often made at a late stage. Although considered rare, the incidence of NETs is increasing. For these reasons, a high index of suspicion is needed. In this article, the different clinical syndromes and the pathophysiology of each tumor as well as the new and emerging biochemical markers and imaging techniques that should be used to facilitate an early diagnosis, follow-up, and prognosis are reviewed.

What Can We Learn from Intraoperative Parathyroid Hormone Levels that Do Not Drop Appropriately?

BACKGROUND

Parathyroidectomy remains the only definitive treatment for primary hyperparathyroidism. We studied our large series of parathyroidectomies to identify factors predictive of failure to meet intraoperative parathyroid hormone (IOPTH) monitoring criteria.

METHODS

We performed a retrospective cohort review of patients who underwent initial parathyroidectomy for primary hyperparathyroidism with IOPTH monitoring. Primary outcome was intraoperative failure, defined as failure to decrease IOPTH by ≥50 % and into normal range. Univariate and multivariate analyses were performed to determine factors associated with intraoperative failure. A subset analysis evaluated 6-month outcomes.

RESULTS

Of 2,185 subjects, 5.0 % (n = 110) experienced intraoperative failure. The intraoperative failure group had more multigland disease (35.2 vs. 16.6 %, p < 0.001) and smaller glands (1.3 vs. 1.5 cm, p = 0.048) compared to patients who experienced intraoperative success. On multivariate analysis, PTH level was statistically, but not clinically, significantly associated with intraoperative failure (odds ratio 1.0, 95 % confidence interval 1.000-1.003). Persistent hyperparathyroidism was identified in 2.5 % (n = 15) of 592 patients with ≥6 month follow-up. Median IOPTH decrease was lower in patients with persistent hyperparathyroidism (67.1 vs. 85.8 %, p < 0.001). IOPTH criteria were 93.7 % sensitive and 40.0 % specific for eucalcemia 6 months postoperatively. Of 15 patients with persistent hyperparathyroidism, 7 underwent reoperation with a 100 % cure rate. Reoperative diagnoses included ectopic mediastinal glands (n = 3), hyperplasia (n = 3), and missed second adenoma (n = 1).

CONCLUSIONS

Intraoperative failure is associated with higher rates of multigland disease and smaller parathyroid glands. Patients with persistent disease had significantly lower decreases in IOPTH, but half of patients who experienced failure by IOPTH criteria were eucalcemic 6 months postoperatively. All patients undergoing reoperation experienced successful cure.

Adrenal medullary hyperplasia is a precursor lesion for pheochromocytoma in MEN2 syndrome

Adrenal medullary hyperplasias (AMHs) are adrenal medullary proliferations with a size < 1 cm, while larger lesions are considered as pheochromocytoma (PCC). This arbitrary distinction has been proposed decades ago, although the biological relationship between AMH and PCC has never been investigated. Both lesions are frequently diagnosed in multiple endocrine neoplasia type 2 (MEN2) patients in whom they are considered as two unrelated clinical entities. In this study, we investigated the molecular relationship between AMH and PCC in MEN2 patients. Molecular aberrations of 19 AMHs and 13 PCCs from 18 MEN2 patients were determined by rearranged during transfection (RET) proto-oncogene mutation analysis and loss of heterozygosity (LOH) analysis for chromosomal regions 1p13, 1p36, 3p, and 3q, genomic areas covering commonly altered regions in RET-related PCC. Identical molecular aberrations were found in all AMHs and PCCs, at similar frequencies. LOH was seen for chromosomes 1p13 in 8 of 18 (44%), 1p36 in 9 of 15 (60%), 3p12-13 in 12 of 18 (67%), and 3q23-24 in 10 of 16 (63%) of AMHs, and for chromosome 1p13 in 13 of 13 (100%), 1p36 in 7 of 11 (64%), 3p12-13 in 4 of 11 (36%), and 3q23-24 in 11 of 12 (92%) of PCCs. Our results indicate that AMHs are not hyperplasias and, in clinical practice, should be regarded as PCCs, which has an impact on diagnosis and treatment of MEN2 patients. We therefore propose to replace the term AMH by micro-PCC to indicate adrenal medullary proliferations of less than 1 cm.

A ten-year clinical update of a large RET p.Gly533Cys kindred with medullary thyroid carcinoma emphasizes the need for an individualized assessment of affected relatives

OBJECTIVE

Reviewing the clinical outcomes of a large kindred with a RET p.Gly533Cys mutation, 10 years after the first description of this kindred, has provided an important set of clinical data for healthcare decision-making.

DESIGN AND PATIENTS

We identified 728 RET533 Brazilian relatives, spread out over 7 generations. We performed clinical examination, biochemical and imaging analyses in the proband and in 103 carriers.

MEASUREMENT AND RESULTS

The proband has been followed without evidence of structural disease in the last 10 years but with elevated calcitonin. The clinical and surgical features of 60 thyroidectomized RET533 relatives were also described. Forty-six patients had MTC (21-72 years), and 11 patients had C-cell hyperplasia (CCH) (5-42 years). Twelve MTC patients with lymph node metastases had a tumour size of 0·7-2·8 cm. Calcitonin level and CEA were correlated with disease stage, and none of the patients presented with an altered PTH or metanephrine. A 63-year-old woman developed pheochromocytoma and breast cancer. Two other RET533 relatives developed lung squamous cell carcinoma and melanoma.

CONCLUSIONS

A vast clinical variability in RET533 presentation was observed, ranging from only an elevated calcitonin level (3%) to local metastatic disease (25%). Many individuals were cured (42%) and the majority had controlled chronic disease (56%), reinforcing the need for individualized ongoing risk stratification assessment. The importance of this update relies on the fact that it allows us to delineate the natural history of RET 533 MEN2A 10 years after its first description.

Cabozantinib (XL184) for the treatment of locally advanced or metastatic progressive medullary thyroid cancer

Cabozantinib (XL184) is an oral multiple receptor tyrosine kinase inhibitor manufactured by Exelixis Inc., CA, USA. It mainly inhibits three tyrosine kinase receptors: MET, VEGFR2 and RET. In both preclinical and clinical studies it has been shown to inhibit tumor angiogenesis, invasiveness and metastases. The most frequent side effects are fatigue, diarrhea, decreased appetite, nausea, weight loss and palmar-plantar erythrodysesthesia. A Phase III clinical trial (EXAM study) of XL184 versus placebo in advanced and progressive medullary thyroid cancer showed a 28 versus 0% overall response rate and a progression-free survival of 11.2 versus 4.0 months (hazard ratio: 0.28; 95% CI: 0.19-0.40; p < 0.0001) in patients treated with cabozantinib and placebo, respectively. The drug has been approved by the US FDA for the treatment of advanced/progressive metastatic medullary thyroid cancer in the USA. The EMA is now evaluating its approval in Europe.

An unusual presentation of MEN2A

A 35-year-old woman presented with non-specific symptoms of fatigue and weight loss. Radiological investigations diagnosed a metastatic process and large bilateral adrenal masses. Histology from a liver biopsy and skin biopsy confirmed a diagnosis of metastatic medullary thyroid cancer. Further biochemical investigations revealed a positive 24-h urinary metanephrine collection and evidence of primary hyperparathyroidism. Genetic testing confirmed a mutant RET oncogene, confirming our clinical suspicion of multiple endocrine neoplasia type 2 (MEN2A) syndrome. The patient had no family history of endocrine disease and presented with widespread metastatic disease, making this an unusual presentation of MEN2A syndrome. Furthermore cutaneous metastases are rarely encountered in conjunction with metastatic medullary thyroid cancer. This case draws attention to the importance of genetic counselling in first-degree relatives of patients with confirmed MEN2A. This allows for timely diagnosis and reduced morbidity and mortality.

2012 European thyroid association guidelines for genetic testing and its clinical consequences in medullary thyroid cancer

Twenty-five percent of medullary thyroid cancers (MTC) are familial and inherited as an autosomal dominant trait. Three different phenotypes can be distinguished: multiple endocrine neoplasia (MEN) types 2A and 2B, in which the MTC is associated with other endocrine neoplasias, and familial MTC (FMTC), which occurs in isolation. The discovery that germline RET oncogene activating mutations are associated with 95-98% of MEN 2/FMTC syndromes and the availability of genotyping to identify mutations in affected patients and their relatives has revolutionized the diagnostic and therapeutic strategies available for the management of these patients. All patients with MTC, both those with a positive familial history and those apparently sporadic, should be submitted to RET genetic screening. Once an RET mutation has been confirmed in an index patient, first-degree relatives should be screened rapidly to identify the 50% who inherited the mutation and are therefore at risk for development of MTC. Relatives in whom no RET mutation is identified can be reassured and discharged from further follow-up, whereas RET-positive subjects (i.e. gene carriers) must be investigated and a therapeutic strategy initiated. These guideline recommendations are derived from the most recent studies identifying phenotype-genotype correlations following the discovery of causative RET gene mutations in MEN 2 eighteen years ago. Three major points will be discussed: (a) identification of patients and relatives who should have genetic screening for RET mutations, (b) management of asymptomatic gene carriers, and (c) ethics.

New and emerging syndromes due to neuroendocrine tumors

Neuroendocrine tumors (NETs) are rare, slow-growing neoplasms characterized by their ability to store and secrete different peptides and neuroamines. Some of these substances cause specific clinical syndromes whereas others are not associated with specific syndromes or symptom complexes. NETs usually have episodic expression that makes diagnosis difficult, erroneous, and often late. For these reasons a high index of suspicion is needed, and it is important to understand the pathophysiology of each tumor to decide which biochemical markers are more useful and when they should be used.

Familial syndromes associated with thyroid cancer in the era of personalized medicine

BACKGROUND

Well-differentiated thyroid cancer accounts for 95% of thyroid malignancies, and 5% of these patients will have familial disease. This compares to 25% of patients with medullary thyroid cancer (MTC) having a familial form; however, this accounts for only 1% of all patients with thyroid cancer. Most cases of familial thyroid cancer are nonmedullary (NMFTC), and have been shown to be present in familial cancer syndromes such as familial adenomatous polyposis, Cowden syndrome, Carney complex, Pendred syndrome, and Werner syndrome. This review discusses the contemporary management of the patients with familial-syndrome-associated thyroid cancer based on their individual risks for developing thyroid cancer.

SUMMARY

Most of the progress in the genetics of familial thyroid cancer has been in patients with MTC. The mutations in patients with isolated NMFTC have not been as well defined as in MTC. They are likely autosomal dominant with reduced penetrance. The patients with these familial syndromes most likely have a susceptibility gene that increases the risk of thyroid cancer. Most of the patients with a familial syndrome and NMFTC will have papillary thyroid carcinoma, suggesting that a specific gene for papillary thyroid carcinoma may also be present. In many cases, patients have a known familial syndrome that has defined risk for thyroid cancer.

CONCLUSIONS

Patients with familial syndromes that are associated with thyroid cancer can be individually categorized based on syndrome risks for developing thyroid cancer. The clinician must also be knowledgeable in recognizing the possibility of an underlying familial syndrome when a patient presents with thyroid cancer.

Biochemical testing for neuroendocrine tumors

In this review, we focus on the use of biochemical markers for the diagnosis of neuroendocrine tumors and exclusion of conditions that masquerade as neuroendocrine tumors. In addition, we outline the use of biochemical markers for follow-up, response to intervention, and determination of prognosis. Previous publications have focused only on markers specific to certain tumor types, but the uniqueness of this chapter is that it presents a new approach ranging from biochemical markers that relate to symptoms to the use of markers that facilitate decision making with regard to optimizing the choices of therapy from the complex arrays of intervention, The sequence of presentation in this chapter is first to provide the usual view, that is, biochemical markers of each tumor type and thereafter the diagnosis of the underlying condition or exclusion thereof and finally the algorithm for their use from the clinical presentation to the suspected diagnosis and the biochemical markers to monitor progression and therapeutic choice. There is also a specific description of the properties of the most important biochemical markers and 2 complications, bone metastasis and carcinoid heart disease, from the biochemical point of view.

Orolabial signs are important clues for diagnosis of the rare endocrine syndrome MEN 2B. Presentation of two unrelated cases

Multiple endocrine neoplasia syndromes (MEN) are genetic disorders with glandular hyperplasia and consecutive malignant neoplasia. MEN type 2B is the least common form of these tumor syndromes. It presents with typical dysmorphic features, mucosal neuromas, ganglioneuromatosis, medullary thyroid carcinoma (MTC) and phaeochromocytoma. The prognosis depends on the presence of MTC. We have surprisingly found two unrelated patients with this syndrome at our department within two weeks. In the medical history of a 17-year-old boy, Crohn's disease had been considered because of abdominal pain and distention. He had marfanoid appearance and previously undergone minor surgeries for a large tongue with neuromas and hypertrophic gums. Two weeks later, a 10-year-old girl presented with a hard palpable mass on her neck. She had thickened lips, neuromas on the tongue and a solitary thyroid nodule. Genetic analysis was carried out in both patients and a heterozygous M918T mutation of the RET proto-oncogene was found. Laboratory tests and imaging studies were consistent with MTC. Phaeochromocytoma was not present. Both patients underwent total thyroidectomy and lymph node dissection. Histological examination confirmed the diagnosis of MTC. In conclusion, the initial diagnosis of MEN 2B should be suspected on the presence of typical facial/oral signs and gastrointestinal symptoms. Hormonal tests and imaging techniques of the thyroid and the adrenals can confirm the clinical diagnosis of MEN 2B and genetic analysis can prove its germline origin.

RET proto-oncogene mutations are restricted to codons 634 and 918 in mainland Chinese families with MEN2A and MEN2B

OBJECTIVE

Multiple endocrine neoplasia type 2 is caused by autosomal dominant gain-of-function mutations in the RET proto-oncogene, which includes multiple endocrine neoplasia type 2A (MEN2A), type 2B (MEN 2B), and familial medullary thyroid carcinoma (FMTC). In this paper we present the phenotype-genotype correlation of 20 unrelated Chinese families with 15 cases of MEN2A and five cases of MEN2B.

DESIGN

Cross-sectional study.

PATIENTS

A total of 147 members from the 20 families were included. Among them, 119 family members were from MEN2A pedigrees (including 15 MEN2A probands) and 28 members from MEN2B pedigrees (including five MEN2B probands).

MEASUREMENTS

Genomic DNA was isolated from peripheral blood leucocytes and was amplified using polymerase chain reaction (PCR). DNA analysis for RET mutations in exons 8, 10, 11, 13, 14, 15 and 16 was performed with specific primers.

RESULTS

Thirty-seven MEN2A and five MEN2B patients were identified as having RET mutations. The incidence of medullary thyroid carcinoma (MTC), pheochromocytoma (PCC) and hyperparathyroidism (HPT) in the 37 MEN2A patients was 91.9, 56.8 and 10.8%, respectively; the onset of MTC in MEN2A patients was earlier than that of PCC and HPT. Five germline mutations, all located at codon 634 of exon11 in the RET proto-oncogene, were detected in all of the 37 MEN2A patients. The highest frequency of the five germline mutations was C634Y (46.7%), followed by C634R (26.7%), C634W (13.3%), C634F (6.7%) and C634S (6.7%). No statistical significance was found between the incidence of PCC and different genotypes of codon 634 in MEN2A patients, whereas the incidence of HPT was closely associated with C634R and C634Y. The gene mutation (M918T) at exon16 of the RET proto-oncogene was present in five MEN2B probands.

CONCLUSIONS

RET proto-oncogene mutations were restricted to codon 634 and 918 in Chinese families with MEN2A and MEN2B. In general the genetic characteristics of these patients with MEN2A and MEN2B reflect the general pattern around the world and it remains to be determined with larger studies in China whether Chinese patients have a different genetic pattern of mutations.

Codon Y791F Mutations in a Large Kindred: Is Prophylactic Thyroidectomy Always Indicated?

BACKGROUND

RET proto-oncogene mutations are associated with medullary thyroid carcinomas usually requiring preventive thyroidectomy in gene carriers. We present a large kindred with the Y791F mutation in the RET proto-oncogene that did not have medullary thyroid carcinomas.

PATIENTS AND METHODS

Eight members of a Danish family with the Y791F mutation participated. All gene carriers underwent pentagastrin testing, and measurements of serum calcitonin. In the index person, exons 10, 11, and 13-16 of the RET proto-oncogene were screened. In the rest of the individuals only exon 13 was analysed. Mutation analysis was done by direct bidirectional sequencing of PCR products on an ABI 3100 Genetic Analyzer (Applied Biosystems, Foster City, CA, USA).

RESULTS

The index person was screened genetically due to goitre at a young age. A total of 27 members of the family underwent genetic testing. Twelve (44.4%, 95% CI: 25.5%-64.7%) had the mutation (age range 13-84 years). None of these had abnormal pentagastrin tests (0%, 95% CI: 0%-26.5%). We found no significant differences in basal serum calcitonin concentrations between gene carriers (mean +/- SD: 0.16 +/- 0.54 pmol/l, n = 11) and non-gene carriers (0.55 +/- 0.86 pmol/l, n = 6, 2 P = 0.29). None showed signs of primary hyperparathyroidism or phaeochromocytoma.

CONCLUSIONS

The Y791F RET proto-oncogene mutation may have a low penetrance. In selected cases, prophylactic thyroidectomy may be replaced by watchful waiting with repeated pentagastrin testing, provided careful evaluation of risks and benefits is performed.

Multiple cutaneous neuromas and macular amyloidosis associated with medullary thyroid carcinoma

Multiple cutaneous neuromas are rarely seen in dermatology practice. We report a case of multiple cutaneous neuromas, macular amyloidosis (MA), and medullary thyroid carcinoma (MTC) and discuss the interrelationship of the associated conditions. Multiple endocrine neoplasia 2 (MEN 2) is a hereditary syndrome that comprises MEN 2A, MEN 2B, and familial MTC. Germline mutations in the RET proto-oncogene is the underlying cause of the syndrome. MEN 2A and MEN 2B show some common endocrine manifestations including MTC and pheochromocytoma. There are reports of families with MA and MEN 2A. Multiple mucosal neuromas occur in 100% of patients with MEN 2B syndrome. Cutaneous neuromas are infrequently reported in MEN 2B syndrome. Our patient was a heterozygote carrier of GAG-->GAC mutation (Glu 768 Asp) in exon 13, codon 768 of the RET proto-oncogene. We speculate that our patient may represent an unusual presentation of MEN 2B or an overlap of MEN 2A and MEN 2B syndromes or a sporadic MTC case with unusual associations.

[Medullar cancer of the thyroid associated with dermal mucinosis]

INTRODUCTION

Dermal mucinosis can be associated with numerous pathologies, in particular involving the thyroid, but has never been described in the case of a medullar cancer of the thyroid (MCT).

CASE-REPORT

A 69-year-old man consulted for a facial erythrosis, which had been developing for a few weeks without any identified triggering factor. The skin biopsy showed dermal mucinosis and tests revealed a sporadic medullar cancer of the thyroid with secondary bone, ganglion and medullar localizations.

DISCUSSION

The association between medullar cancer of the thyroid and dermal mucinosis has never been described. Several hypotheses may explain this: the thyroid pathology itself, whatever its nature, the capacity of the MCT to synthesize mucin and the medullar metastatic overgrowth.

Second primary cancers in thyroid cancer patients: a multinational record linkage study

CONTEXT

Increasing incidence and improved prognosis of thyroid cancer have led to concern about the development of second primary cancers, especially after radioiodine treatment. Thyroid cancer can also arise as a second primary neoplasm after other cancers.

OBJECTIVE

The objective of the study was to assess the risk of second primary cancer after thyroid cancer and vice versa.

DESIGN

This was a multinational record linkage study.

SETTING

The study was conducted at 13 population-based cancer registries in Europe, Canada, Australia, and Singapore.

PATIENTS OR OTHER PARTICIPANTS

A cohort of 39,002 people (356,035 person-yr of follow-up) with primary thyroid cancer were followed up for SPN for up to 25 yr, and 1,990 cases of thyroid cancer were diagnosed after another primary cancer.

MAIN OUTCOME MEASURES

To assess any possible excess of second primary neoplasms after thyroid cancer, the observed numbers of neoplasms were compared with expected numbers derived from age-, sex-, and calendar period-specific cancer incidence rates from each of the cancer registries, yielding standardized incidence ratios (SIRs). The SIR of second primary thyroid cancer after various types of cancer was also calculated.

RESULTS

During the observation period, there were 2821 second primary cancers (all sites combined) after initial diagnosis of thyroid cancer, SIR of 1.31 (95% confidence interval 1.26-1.36) with significantly elevated risks for many specific cancers. Significantly elevated risks of second primary thyroid cancer were also seen after many types of cancer.

CONCLUSION

Pooled data from 13 cancer registries show a 30% increased risk of second primary cancer after thyroid cancer and increased risks of thyroid cancer after various primary cancers. Although bias (detection, surveillance, misclassification) and chance may contribute to some of these observations, it seems likely that shared risk factors and treatment effects are implicated in many. When following up patients who have been treated for primary thyroid cancer, clinicians should maintain a high index of suspicion for second primary cancers.

New prognostic scales LAST-1 and LAST-2: supporting prediction and staging of thyroid cancer

INTRODUCTION

Epidemiologically, thyroid gland tumors are lesions of the highest importance among endocrine tumors in humans. Although the results of surgical treatment of the highly differentiated (follicular and papillary) tumors seem to be satisfactory, treatment of the poorly differentiated (medullary and anaplastic) tumor still demands clinical and basic investigations. In this study the authors sought to evaluate clinical and molecular factors that could contribute to preoperative detection of more advanced thyroid cancers (i.e., those that exhibit extrathyroid spread and lymph node invasion).

METHODS

A total of 27 patients operated on for thyroid cancer were evaluated according to age, sex, time from the onset of the disease, cytogenetic changes, and loss of heterozygosity (LOH) in 14 microsatellite markers. The output variables were defined according to postoperative findings and the TNM 2002 score. The T1-2 N0 M0 cases were defined as local malignancy (LM); and T3-4 any N any M, any T N1 any M, or any T any N M1 were considered advanced malignancy (AM). The control groups consisted of 25 patients with multinodular goiter (MNG) and 32 patients with follicular adenoma (FA). In all cases, clinical and molecular data similar to those listed above were collected, excluding staging and follow-up information.

RESULTS

There was no predominant specific type of chromosomal aberration observed and no marker lost in more than five patients (18%). The logistic regression identified three input variables as contributing significantly to the dichotomized outcome measure (LM vs. AM): LOH in any of the examined loci, age of the patient at the presentation, and the sex of the patient. Furthermore, discriminant analysis revealed four input variables differentiating among TC, FA, and MNG patients. Based on the multivariate analysis results, two numeric prognostic scales were fashioned: LAST-1, a scale applicable to differentiation of thyroid cancers at different degrees of clinical advancement; and LAST-2, a scale applicable to differentiation of any thyroid lumps.

CONCLUSIONS

It was concluded that LOH and the age and sex of the patients can provide sufficient data to predict thyroid cancer with a high degree of clinical advancement. LAST-1 scale is a reliable tool for identifying these patients. The LAST-2 scale gives supportive information about the character of thyroid lumps, distinguishing TC from MNG and FA.

Das familiäre Nebenschilddrüsenkarzinom

In contrast to primary hyperparathyroidism, parathyroid carcinoma is a rare disease. In patients with hyperparathyroidism jaw tumor (HPT-JT) syndrome, caused by germline mutations in HRPT2, the development of parathyroid carcinoma is estimated to be 10-15%. This review summarizes the clinical and molecular genetic data of about 100 patients in the literature and three of our own cases. Unfortunately, osteofibromas, which might enable timely diagnosis of HPT-JT syndrome, occur in only about 30% of patients; about 80% have uniglandular disease. Based on the current data, a general recommendation to perform prophylactic parathyroidectomy cannot be given. However, thorough screening of patients at risk is mandatory. Of note in patients thought to have sporadic parathyroid carcinoma, germline HRPT2 mutations are found in up to 20%. Hence, any patient with parathyroid carcinoma should undergo HRPT2 mutation analysis.

Analysis of inherited genetic variants in ret proto-oncogene of Brazilian patients with apparently sporadic medullary thyroid carcinoma

Mutations in different exons of ret proto-oncogene are responsible for the development of medullary thyroid carcinoma (MTC). The mutations can occur as sporadic or as part of multiple endocrine neoplasia (MEN) type 2 hereditary syndromes. Here we report the first focused study of sporadic MTC in Brazilian patients regarding clinical and molecular analysis of ret proto-oncogene. Our study seeks to estimate the risk of hereditary MTC cases among apparently sporadic cases in a Brazilian population and describe ret genetic variants in their germinative lineage. Germinative sequence variants were screened by DNA sequencing and denaturing gradient gel electrophoresis (DGGE) analysis of exons 10, 11, 13, 14, 15, and 16 of 24 Brazilian patients with apparently sporadic MTC. We identified 1 inherited case of 24 (4%) patients with apparently sporadic MTC. Polymorphisms for the ret proto-oncogene coding region were identified in codon 769 of exon 13 (LeuCTT--> LeuCTG) at a frequency of 13% (3/24) and in codon 904 of exon 15 (SerTCC--> SerTCG) at a frequency of 16.6% (4/24). The observed frequency (4%) of inherited disease among apparent sporadic MTC strengthens routine application of ret proto-oncogene germinative DNA screening in all cases of apparently sporadic MTC ascertained at Brazilian cancer hospitals.

The T1799A BRAF mutation is not a germline mutation in familial nonmedullary thyroid cancer

OBJECTIVE

Familial nonmedullary thyroid cancer (FNMTC) is relatively common but its predisposing genetic alteration is unclear. As the somatic T1799A BRAF mutation is highly prevalent in papillary thyroid cancer, the aim was to test whether this mutation was a susceptibility mutation for FNMTC.

SUBJECTS AND METHODS

The T1799A BRAF mutation as a possible germline mutation was examined in 40 subjects from 23 families with a history of FNMTC. Direct DNA sequencing was performed on white blood cell DNA samples to analyse the mutation status.

RESULTS

No T1799A BRAF mutation was found in this group of subjects as germline mutation.

CONCLUSION

The T1799A BRAF mutation is not a germline mutation or susceptibility genetic event for FNMTC.