Pheochromocytoma in multiple endocrine neoplasia type 2: European study. The Euromen Study Group

Rare and aggressive metastatic pheochromocytoma recurrence in a patient with MEN 2A syndrome

An adult male in his early 30s diagnosed with multiple endocrine neoplasia type 2A syndrome, confirmed through genetic testing, presented as bilateral pheochromocytoma in a metachronous fashion, primary hyperparathyroidism and medullary thyroid carcinoma. Left and right adrenalectomy was done 9 years and 3 years ago, respectively. He was also subjected to total thyroidectomy with neck dissection and left inferior parathyroidectomy. During surveillance monitoring, 24-hour total urine metanephrines were elevated 13.977 mg (Normal value 0-1 mg) 1 year after right adrenalectomy. Adrenal CT scan demonstrated a 2.1 cm ovoid focus in the right suprarenal region, and functional imaging (131I meta-iodobenzylguanidine (MIBG scan) showed an avid uptake on the right frontal bone. Excision of the right adrenal bed and the right frontal bone tumour was performed, and metastatic pheochromocytoma was confirmed histologically. The patient achieved clinical and biochemical remission postoperatively and is currently receiving steroid and thyroxine replacement.

Primary Hyperparathyroidism in Multiple Endocrine Neoplasia Type 2A in Denmark 1930–2021: A Nationwide Population-Based Retrospective Study

Studies of primary hyperparathyroidism (PHPT) in multiple endocrine neoplasia type 2A (MEN 2A) shows divergence in frequency, disease definition, reporting of clinical characteristics and traces of selection bias. This is a nationwide population-based retrospective study of PHPT in MEN 2A, suggesting a representative frequency, with complete reporting and a strict PHPT definition. The Danish MEN 2A cohort 1930-2021 was used. Of 204 MEN 2A cases, 16 had PHPT, resulting in a frequency of 8% (CI, 5-12). Age-related penetrance at 50 years was 8% (CI, 4-15). PHPT was seen in the American Thyroid Association moderate (ATA-MOD) and high (ATA-H) risk groups in 62% and 38% of carriers, respectively. Median age at PHPT diagnosis was 45 years (range, 21-79). A total of 75% were asymptomatic and 25% were symptomatic. Thirteen underwent parathyroid surgery, resulting in a cure of 69%, persistence in 8% and recurrence in 23%. In this first study with a clear PHPT definition and no selection bias, we found a lower frequency of PHPT and age-related penetrance, but a higher age at PHPT diagnosis than often cited. This might be affected by the Danish RET p.Cys611Tyr founder effect. Our study corroborates that PHPT in MEN 2A is often mild, asymptomatic and is associated with both ATA-MOD and ATA-H variants. Likelihood of cure is high, but recurrence is not infrequent and can occur decades after surgery.

Clinical presentation and diagnostic evaluation of pheochromocytoma: case series and literature review

BACKGROUND

Pheochromocytoma is a rare tumor frequently overlooked mainly due to the wide range of its clinical presentation, which may vary from entirely untypical signs and symptoms to life-threatening complications.

METHODS

The present study aims to present a case series recently treated in our center, with emphasis placed on patients' specific characteristics, clinical presentation and diagnostic evaluation. Relevant literature and current guidelines are being briefly reviewed to summarize screening for pheochromocytoma and appropriate diagnostic procedures.

RESULTS

While the classic symptoms include headache, palpitations and sweating with permanent or paroxysmal hypertension, a wide range of clinical manifestations may be attributed to pheochromocytoma. The initial screening test is measurement of plasma or 24-hour urine metanephrine levels. Abdominal computerized tomography with intravenous contrast infusion is suggested as the imaging examination of choice, whereas magnetic resonance imaging should be preferred over CT in exceptional cases. 123I-metaiodobenzylguanidine scintigraphy is particularly useful for establishing the diagnosis of pheochromocytoma and should be further applied to detect or exclude possible metastatic lesions.

CONCLUSION

Early diagnosis of pheochromocytoma is of great significance not only because it represents a curable form of secondary hypertension, but also because it is often related to familial syndromes, malignancy or metastatic disease. Physicians need to be familiar with relevant clinical manifestations and diagnostic steps to raise clinical suspiction of pheochromocytoma and establish a timely diagnosis.

A Case Study of Multiple Endocrine Neoplasia Type 2A

Multiple endocrine neoplasia type 2 is an autosomal dominant neoplastic syndrome with subtypes multiple endocrine neoplasia type 2A, multiple endocrine neoplasia type 2B, and familial medullary thyroid carcinoma. Medullary thyroid carcinoma universally coincides with multiple endocrine neoplasia type 2. Multiple endocrine neoplasia type 2A is a rare disease and the affected patients are generally asymptomatic. The morbidity and mortality are mainly due to medullary thyroid carcinoma and often proper clinical workup is warranted for expedited surgical intervention. Total thyroidectomy along with neck dissection may be required for disease control. This report will cover a patient who presented with medullary thyroid carcinoma and was worked up to have multiple endocrine neoplasia type 2A. She underwent total thyroidectomy with central neck dissection.

Metastatic cluster 2-related pheochromocytoma/paraganglioma: a single-center experience and systematic review

Risk of metastatic disease in the cluster 2-related pheochromocytoma/paraganglioma (PPGL) is low. In MEN2 patients, identification of origin of metastases from pheochromocytoma (PCC) or medullary thyroid carcinoma (MTC) is challenging as both are of neuroendocrine origin. We aim to describe our experience and perform a systematic review to assess prevalence, demographics, biochemistry, diagnostic evaluation, management, and predictors of cluster 2-related metastatic PPGL. Retrospective analysis of 3 cases from our cohort and 43 cases from world literature was done. For calculation of prevalence, all reported patients (n = 3063) of cluster 2 were included. We found that the risk of metastasis in cluster 2-related PPGL was 2.6% (2% in RET, 5% in NF1, 4.8% in TMEM127 and 16.7% in MAX variation). In metastatic PCC in MEN2, median age was 39 years, bilateral tumors were present in 71% and median tumor size was 9.7 cm (range 4-19) with 43.5% mortality. All patients had a primary tumor size ≥4 cm. Origin of primary tumor was diagnosed by histopathology of metastatic lesion in 11 (57.9%), 131I-MIBG scan in 6 (31.6%), and selective venous sampling and CT in 1 (5.3%) patient each. In subgroup of neurofibromatosis 1 (NF1), median age was 46 years (range 14-59) with median tumor size 6 cm and 57% mortality. To conclude, the risk of metastatic disease in cluster 2-related PPGL is low, being especially high in tumors with size ≥4 cm and associated with high mortality. One-third patients of NF1 with metastatic PPGL had presented in second decade of life. Long-term studies are needed to formulate management recommendations.

Laparoscopic resection of aortocaval paraganglioma diagnosed by serial increase in urinary metanephrines after bilateral adrenalectomy in a patient with multiple endocrine neoplasia type 2A

INTRODUCTION

Although bilateral pheochromocytoma is prevalent in patients with multiple endocrine neoplasia type 2, extra-adrenal tumors rarely occur in the aortocaval area.

CASE PRESENTATION

A 35-year-old man with multiple endocrine neoplasia type 2A (RET codon Cys634Arg mutation) underwent bilateral adrenalectomy for metachronous pheochromocytoma. After bilateral adrenalectomy, urinary metanephrines decreased below the measurement sensitivity. The levels of urinary metanephrines were serially elevating to a peak of 187 ng/mgCr during the 11-year follow-up period; however, urinary normetanephrine levels remained almost stable. 123I-metaiodobenzylguanidine single-photon emission computed tomography revealed abnormal accumulation with a mass of 25 × 18 mm in diameter in the aortocaval space cranially to the renal vessels. The extra-adrenal paraganglioma was successfully resected using transperitoneal laparoscopic surgery.

CONCLUSION

The serial increase in urinary metanephrine levels was useful for the detection of the recurrent tumor in a patient who had undergone bilateral adrenalectomy.

Mutation Profile of Aggressive Pheochromocytoma and Paraganglioma with Comparison of TCGA Data

Simple Summary

Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors arising from chromaffin cells of the adrenal medulla, or extra-adrenal paraganglia, respectively. In PPGLs, germline or somatic mutations in one of the known susceptibility genes are identified in up to 60% patients. Recent WHO classification defines that all PPGLs can have metastatic potential. The term, ‘malignant’ is replaced with ‘metastatic’ in this group of tumors. However, the peculiar genetic events that drive the aggressive behavior, including metastasis in PPGLs are yet poorly understood. We performed targeted next-generation sequencing analysis to characterize the mutation profile in fifteen aggressive PPGL patients and compared accessible data of aggressive PPGLs from The Cancer Genome Atlas (TCGA) with findings of our cohort. This targeted mutational analysis might expand the mutation profile of aggressive PPGLs, and may also be useful in detecting the possible experimental therapeutic options or predicting poor prognosis.

Abstract

In pheochromocytoma and paraganglioma (PPGL), germline or somatic mutations in one of the known susceptibility genes are identified in up to 60% patients. However, the peculiar genetic events that drive the aggressive behavior including metastasis in PPGL are poorly understood. We performed targeted next-generation sequencing analysis to characterize the mutation profile in fifteen aggressive PPGL patients and compared accessible data of aggressive PPGLs from The Cancer Genome Atlas (TCGA) with findings of our cohort. A total of 115 germline and 34 somatic variants were identified with a median 0.58 per megabase tumor mutation burden in our cohort. The most frequent mutation was SDHB germline mutation (27%) and the second frequent mutations were somatic mutations for SETD2, NF1, and HRAS (13%, respectively). Patients were subtyped into three categories based on the kind of mutated genes: pseudohypoxia (n = 5), kinase (n = 5), and unknown (n = 5) group. In copy number variation analysis, deletion of chromosome arm 1p harboring SDHB gene was the most frequently observed. In our cohort, SDHB mutation and pseudohypoxia subtype were significantly associated with poor overall survival. In conclusion, subtyping of mutation profile can be helpful in aggressive PPGL patients with heterogeneous prognosis to make relevant follow-up plan and achieve proper treatment.

Multiple endocrine neoplasia type 2: A reveiw

Multiple endocrine neoplasias are rare hereditary syndromes some of them with malignant potential. Multiple endocrine neoplasia type 2 (MEN 2) is an autosomal dominant hereditary cancer syndrome due to germline variants in the REarranged during Transfection (RET) proto-oncogene. There are two distinct clinical entities: MEN 2A and MEN 2B. MEN 2A is associated with medullary thyroid carcinoma (MTC), phaeochromocytoma, primary hyperparathyroidism, cutaneous lichen amyloidosis and Hirschprung's disease and MEN 2B with MTC, phaeochromocytoma, ganglioneuromatosis of the aerodigestive tract, musculoskeletal and ophthalmologic abnormalities. Germline RET variants causing MEN 2 result in gain-of-function; since the discovery of the genetic variants a thorough search for genotype-phenotype associations began in order to understand the high variability both between families and within family members. These studies have successfully led to improved risk classification of prognosis in relation to the genotype, thus improving the management of the patients by thorough genetic counseling. The present review summarizes the recent developments in the knowledge of these hereditary syndromes as well as the impact on clinical management, including genetic counseling, of both individual patients and families. It furthermore points to future directions of research for better clarification of timing of treatments of the various manifestations of the syndromes in order to improve survival and morbidity in these patients.

First Experience Using 18F-Flubrobenguane PET Imaging in Patients with Suspected Pheochromocytoma or Paraganglioma

Pheochromocytomas and paragangliomas are a rare tumor entity originating from adrenomedullary chromaffin cells in the adrenal medulla or in sympathetic, paravertebral ganglia outside the medulla. Small lesions are especially difficult to detect by conventional CT or MRI and even by SPECT with the currently available radiotracers (e.g., metaiodobenzylguanidine [MIBG]). The novel PET radiotracer ¹⁸F-flubrobenguane could change the diagnostic paradigm in suspected pheochromocytomas and paragangliomas because of its homology with MIBG and the general advantages of PET imaging. The aim of this retrospective analysis was to evaluate ¹⁸F-flubrobenguane in pheochromocytomas and paragangliomas and to investigate the biodistribution in patients. Methods: Twenty-three patients with suspected pheochromocytoma or paraganglioma underwent PET/CT or PET/MRI at 63 ± 24 min after injection of 256 ± 33 MBq of ¹⁸F-flubrobenguane. The SUV_mean and SUV_max of organs were measured with spheric volumes of interest. Threshold-segmented volumes of interest were used to measure the SUV_mean or SUV_max of the tumor lesions. One reader evaluated all cross-sectional imaging datasets (CT or MRI) separately, as well as the PET hybrid datasets, and reported the lesion number and size. The diagnostic certainty for a positive lesion was scored on a 3-point scale. Results: ¹⁸F-flubrobenguane showed a reproducible, stable biodistribution, with the highest SUV_max and SUV_mean being in the thyroid gland (30.3 ± 2.2 and 22.5 ± 1.6, respectively), pancreas (12.2 ± 0.8 and 9.5 ± 0.7, respectively), and tumor lesions (16.8 ± 1.7 and 10.1 ± 1.1, respectively) and the lowest SUV_max and SUV_mean being in muscle (1.1 ± 0.06 and 0.7 ± 0.04, respectively) and the lung (2.5 ± 0.17 and 1.85 ± 0.13, respectively). In a subgroup analysis, a significantly higher average SUV_mean was seen for both pheochromocytoma and paraganglioma than for healthy adrenal glands (11.9 ± 2.0 vs. 9.9 ± 1.5 vs. 3.7 ± 0.2, respectively). In total, 47 lesions were detected. The reader reported more and smaller lesions with higher certainty in PET hybrid imaging than in conventional imaging; however, statistical significance was not reached. Of the 23 (23/47, 49%) lesions smaller than 1 cm, 61% (14/23) were found on hybrid imaging only. Conclusion: Our preliminary data suggest ¹⁸F-flubrobenguane PET to be a new, effective staging tool for patients with suspected pheochromocytoma or paraganglioma. Major advantages are the fast acquisition and high spatial resolution of PET imaging and the intense uptake in tumor lesions, facilitating detection. Further studies are warranted to define the role of ¹⁸F-flubrobenguane PET, particularly in comparison to standard diagnostic procedures such as MRI or ¹²³I-MIBG SPECT/CT.

Primary hyperparathyroidism as first manifestation in multiple endocrine neoplasia type 2A: an international multicenter study

OBJECTIVE

Multiple endocrine neoplasia type 2A (MEN 2A) is a rare syndrome caused by RET germline mutations and has been associated with primary hyperparathyroidism (PHPT) in up to 30% of cases. Recommendations on RET screening in patients with apparently sporadic PHPT are unclear. We aimed to estimate the prevalence of cases presenting with PHPT as first manifestation among MEN 2A index cases and to characterize the former cases.

DESIGN AND METHODS

An international retrospective multicenter study of 1085 MEN 2A index cases. Experts from MEN 2 centers all over the world were invited to participate. A total of 19 centers in 17 different countries provided registry data of index cases followed from 1974 to 2017.

RESULTS

Ten cases presented with PHPT as their first manifestation of MEN 2A, yielding a prevalence of 0.9% (95% CI: 0.4-1.6). 9/10 cases were diagnosed with medullary thyroid carcinoma (MTC) in relation to parathyroid surgery and 1/10 was diagnosed 15 years after parathyroid surgery. 7/9 cases with full TNM data were node-positive at MTC diagnosis.

CONCLUSIONS

Our data suggest that the prevalence of MEN 2A index cases that present with PHPT as their first manifestation is very low. The majority of index cases presenting with PHPT as first manifestation have synchronous MTC and are often node-positive. Thus, our observations suggest that not performing RET mutation analysis in patients with apparently sporadic PHPT would result in an extremely low false-negative rate, if no other MEN 2A component, specifically MTC, are found during work-up or resection of PHPT.

Clinical Characteristics and Outcome of Patients With Pheochromocytoma: A Single Center Tertiary Care Experience

Objective

The aim of this study was to evaluate the demographic and clinical characteristics of patients with pheochromocytoma and determine the treatment outcome with overall survival rates of patients with pheochromocytoma.

Methods

A retrospective, cross-sectional study was performed on all the patients with histologically proven pheochromocytoma presenting to Shaukat Khanum Memorial Cancer Hospital and Research Center (SKMCH & RC) Lahore, between August 2006 and July 2018. Clinical, biochemical and radiological data were collected at presentation, post-surgery, at discharge and till the last follow-up; data was retrieved from hospital records. Cure was defined as no evidence of disease biochemically, clinically, and structurally.

Results

This study included 29 patients, 69% were female. The three most common symptoms were abdominal pain (51.7%), hypertension (44.8%) and headache (41.4%). Most pheochromocytomas were sporadic (82.8%), all were adrenal gland tumors, and 89.7% were unilateral. All patients underwent adrenalectomy. Open adrenalectomy was performed in 25 patients whereas four underwent laparoscopic adrenalectomy. Fifteen patients experienced postoperative complications. The most frequently documented intraoperative complication was hypotension. Death occurred in two patients, one patient died of metastatic disease secondary to malignant pheochromocytoma and the other patient died from perioperative complications. Cure was documented biochemically and/or radiologically in 96.5% patients.

Conclusions

Abdominal pain was predominant presenting feature most likely due to large tumor size. Most patients presenting to SKMCH & RC, had large intra-abdominal tumors with high cure rate. Mortality was low despite high rate of perioperative complications.

A Guide to Pheochromocytomas and Paragangliomas

Pheochromocytomas and extra-adrenal paragangliomas are rare neuroendocrine neoplasms with characteristic histologic and immunohistochemical features. These tumors can arise in several anatomic locations, necessitating that their diagnostic recognition extends beyond the realm of endocrine disorders. A practical and reproducible risk stratification system for these tumors is still in development. In this rapidly evolving era of molecular medicine, it is essential for pathologists to equip themselves with a framework for understanding the classification of paragangliomas and pheochromocytomas and be informed of how they might advise their colleagues with regard to prognostication and appropriate follow-up.

An Update on the Histology of Pheochromocytomas: How Does it Relate to Genetics?

Pheochromocytomas are rare neuroendocrine tumors of the adrenal gland, whereas any extra-adrenal tumor with similar histology is designated as paraganglioma. These tumors have a very high rate of germline mutations in a large number of genes, up to 35% to 40%, frequently predisposing for other tumors as well. Therefore, they represent a phenomenal challenge for treating physicians. This review focuses on pheochromocytomas only, with special attention to gross and microscopic clues to the diagnosis of genetic syndromes, including the role of succinate dehydrogenase subunit A and subunit B immunohistochemistry as surrogate markers for genetic analysis in the field of succinate dehydrogenase subunit gene mutations.

[Pheochromocytoma in multiple endocrine neoplasia 2A associated with pulmonary tuberculosis presenting as abdominal pain: a case report and literature review]

Pheochromocytoma is a catecholamine-producing neoplasm that may occur sporadically or associated with hereditary diseases, such as multiple endocrine neoplasia. The classic symptoms are headache, sweating, and palpitations and are attributed to the sympathetic nervous system activity, usually presenting as paroxysms. On the other hand, pulmonary tuberculosis is an infectious disease considered a public health problem in many countries, whose incidence depends on risk factors such as immunosuppression. It is well known that endocrine-tumor diseases such as multiple endocrine neoplasia can predispose to chronic inflammation and immunosuppression. We report the case of a 38-year-old male patient who had an episode of arterial hypertension and abdominal pain as the first symptoms of a pheochromocytoma associated with multiple endocrine neoplasia type 2A. The patient developed pulmonary tuberculosis simultaneously, but we managed to treat both entities and achieve a favorable clinical course.

Multiple Endocrine Neoplasia Syndromes from Genetic and Epigenetic Perspectives

Multiple endocrine neoplasia (MEN) syndromes are infrequent inherited disorders in which more than one endocrine glands develop noncancerous (benign) or cancerous (malignant) tumors or grow excessively without forming tumors. There are 3 famous and well-known forms of MEN syndromes (MEN 1, MEN 2A, and MEN 2B) and a newly documented one (MEN4). These syndromes are infrequent and occurred in all ages and both men and women. Usually, germ line mutations that can be resulted in neoplastic transformation of anterior pituitary, parathyroid glands, and pancreatic islets in addition to gastrointestinal tract can be an indicator for MEN1. The medullary thyroid cancer (MTC) in association with pheochromocytoma and/or multiple lesions of parathyroid glands with hyperparathyroidism can be pointer of MEN2 which can be subgrouped into the MEN 2A, MEN 2B, and familial MTC syndromes. There are no distinct biochemical markers that allow identification of familial versus nonfamilial forms of the tumors, but familial MTC usually happens at a younger age than sporadic MTC. The MEN1 gene (menin protein) is in charge of MEN 1 disease, CDNK1B for MEN 4, and RET proto-oncogene for MEN 2. The focus over the molecular targets can bring some hope for both diagnosis and management of MEN syndromes. In the current review, we look at this disease and responsible genes and their cell signaling pathway involved.

Malignant Pheochromocytoma in Multiple Endocrine Neoplasia Type 2B Syndrome. Case Report and Review of the Literature

A malignant behavior (i.e., distant metastatic spread) has been recorded in 3-4% of pheochromocytomas occurring in the context of multiple endocrine neoplasia type 2A syndrome, but has never been documented in patients with the type 2B form. In this report we describe a case of malignant pheochromocytoma arising in the latter syndrome setting. The patient, a white young male, had the full-blown syndrome, including multicentric, bilateral medullary thyroid carcinoma metastatic to regional lymph nodes, mucosal neuromas, digestive ganglioneuromatosis, marfanoid habitus, and bumpy lips. Three and a half years after surgical resection of an apparently benign adrenal pheochromocytoma he developed widespread osseous metastases. The presence of hypertensive crises and high urinary catecholamine excretion rates, coupled to moderate hypercalcitoninemia, normal circulating carcinoembryonic antigen levels, negative whole-body 99mTc-(V) dimercaptosuccinic acid scan, and absence of neck or mediastinal disease by magnetic resonance imaging, proved that the metastases were from his previous adrenal and not thyroid tumor. Furthermore, since the bone metastases strongly accumulated 131I-metaiodobenzylguanidine, several courses of the radiocompound were given, which resulted in an objective, though partial, tumor regression.

Metastatic pheochromocytoma in MEN 2A: A rare association

A 45-year-old woman was diagnosed as having multiple endocrine neoplasia type 2A in 2014. She had bilateral pheochromocytoma, medullary thyroid carcinoma and biopsy-proven cutaneous lichen amyloidosis in the interscapular area. She underwent bilateral adrenalectomy; following which, she achieved clinical and biochemical remission. She was planned for total thyroidectomy at a later date; however, she was lost to follow-up. She presented to us again in December 2016 with abdominal pain. Examination revealed hypertension with postural drop. Positron emission tomography scan showed Ga⁶⁸ and fluorodeoxyglucose (FDG)-avid suprarenal, hepatic, peritoneal and mesenteric masses with abdominal lymph nodes. Twenty-four-hour urinary metanephrines/normetanephrines were elevated. Serum calcitonin was as high as it was 2-1/2 years ago. Ultrasonography-guided fine-needle aspiration cytology (FNAC) from the liver mass revealed neuroendocrine cells that did not stain for calcitonin. Hence, a diagnosis of metastatic pheochromocytoma was made. She underwent total thyroidectomy and was started on cyclophosphamide, vincristine, dacarbazine-based chemotherapy regimen.

Advances in the management of MEN2: from improved surgical and medical treatment to novel kinase inhibitors

Medullary thyroid carcinoma (MTC), a tumor derived from the neural crest, occurs either sporadically or as the dominant component of the type 2 multiple endocrine neoplasia (MEN) syndromes, MEN2A and MEN2B. The discovery that mutations in the RET protooncogene cause hereditary MTC was of great importance, since it led to the development of novel methods of diagnosis and treatment. For example, the detection of a mutated RET allele in family members at risk for inheriting MEN2A or MEN2B signaled that they would develop MTC, and possibly other components of the syndromes. Furthermore, the detection of a mutated allele created the opportunity, especially in young children, to remove the thyroid before MTC developed, or while it was confined to the gland. The discovery also led to the development of molecular targeted therapeutics (MTTs), mainly tyrosine kinase inhibitors, which were effective in the treatment of patients with locally advanced or metastatic MTC. While responses to MTTs are often dramatic, they are highly variable, and almost always transient, because the tumor cells become resistant to the drugs. Clinical investigators and the pharmaceutical industry are focusing on the development of the next generation of MTTs, which have minimal toxicity and greater specificity for mutated RET.

Phaeochromocytoma in multiple endocrine neoplasia type 2: RET codon-specific penetrance and changes in management during the last four decades

OBJECTIVES

We describe phaeochromocytoma (phaeo) penetrance in multiple endocrine neoplasia type 2 (MEN2) according to RET protooncogene-specific mutations and report changes in phaeo diagnosis and management from 1968 to 2015.

DESIGN

This retrospective chart review included 309 MEN2 patients from one specialized ambulatory care centre. Phaeo patients were categorized by diagnosis date: early, 1968-1996, n=40, and recent, 1997-2015, n=45.

RESULTS

Phaeochromocytoma was diagnosed in 85/309 patients with RET mutations in the following exons (phaeos/all carriers, %): exon 11 (56/120, 46.6%); exon 16 (7/17, 41.2%), exon 10 (14/47, 29.8%), and exon 13-15 (2/116, 1.7%). Age at phaeo diagnosis differed according to affected exon: 21.9±1.5 years, exon 16; 34.1±11.6 years, exon 11; and 41.8±8.8 years, exon 10. Age-related phaeo penetrance differed among five amino acid substitutions at codon 634 and was highest for Cys634Arg and Cys634Tyr. Age at diagnosis was 34.4±11.6 years in the early and recent groups. Phaeochromocytoma and medullary thyroid carcinoma (MTC) were diagnosed synchronously in 21/40 (early) vs 8/45 (recent) and metachronously in 19/40 vs 37/45 cases. Diagnostic methods significantly changed from clinical (22/40 vs 4/45) to biochemical and/or imaging based (14/40 vs 35/45). Phaeochromocytoma diameter at diagnosis was 4.6 vs 2.6 cm.

CONCLUSION

Phaeochromocytoma penetrance and age of diagnosis are highly correlated with MTC aggressiveness based on RET mutation status, with higher penetrance and younger age of diagnosis associated with more aggressive MTC. Penetrance steadily increases with age. At-risk patients require lifelong follow-up.

A Comprehensive Review of Pediatric Tumors and Associated Cancer Predisposition Syndromes

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

Precision medicine in pheochromocytoma and paraganglioma: current and future concepts

Pheochromocytoma and paraganglioma (PPGL) are rare diseases but are also amongst the most characterized tumour types. Hence, patients with PPGL have greatly benefited from precision medicine for more than two decades. According to current molecular biology and genetics-based taxonomy, PPGL can be divided into three different clusters characterized by: Krebs cycle reprogramming with oncometabolite accumulation or depletion (group 1a); activation of the (pseudo)hypoxia signalling pathway with increased tumour cell proliferation, invasiveness and migration (group 1b); and aberrant kinase signalling causing a pro-mitogenic and anti-apoptotic state (group 2). Categorization into these clusters is highly dependent on mutation subtypes. At least 12 different syndromes with distinct genetic causes, phenotypes and outcomes have been described. Genetic screening tests have a documented benefit, as different PPGL syndromes require specific approaches for optimal diagnosis and localization of various syndrome-related tumours. Genotype-tailored treatment options, follow-up and preventive care are being investigated. Future new developments in precision medicine for PPGL will mainly focus on further identification of driver mechanisms behind both disease initiation and malignant progression. Identification of novel druggable targets and prospective validation of treatment options are eagerly awaited. To achieve these goals, we predict that collaborative large-scale studies will be needed: Pheochromocytoma may provide an example for developing precision medicine in orphan diseases that could ultimately aid in similar efforts for other rare conditions.

Revised American Thyroid Association guidelines for the management of medullary thyroid carcinoma

INTRODUCTION

The American Thyroid Association appointed a Task Force of experts to revise the original Medullary Thyroid Carcinoma: Management Guidelines of the American Thyroid Association.

METHODS

The Task Force identified relevant articles using a systematic PubMed search, supplemented with additional published materials, and then created evidence-based recommendations, which were set in categories using criteria adapted from the United States Preventive Services Task Force Agency for Healthcare Research and Quality. The original guidelines provided abundant source material and an excellent organizational structure that served as the basis for the current revised document.

RESULTS

The revised guidelines are focused primarily on the diagnosis and treatment of patients with sporadic medullary thyroid carcinoma (MTC) and hereditary MTC.

CONCLUSIONS

The Task Force developed 67 evidence-based recommendations to assist clinicians in the care of patients with MTC. The Task Force considers the recommendations to represent current, rational, and optimal medical practice.

Pheochromocytomas in Multiple Endocrine Neoplasia Type 2

Pheochromocytoma (PC) is a neuroendocrine tumor that originates from chromaffin cells of the adrenal medulla. The production of catecholamines, including epinephrine, norepinephrine and dopamine, may lead to haemodynamic instability. Over 30% of PCs are associated with germline mutations, including re-arranged in transfection (RET) mutations seen in multiple endocrine neoplasia type 2 (MEN2) syndromes. Around 40% of individuals with MEN2 develop PC, though it is rarely the presenting feature. Compared to sporadic PC, MEN2-associated PC is more likely to be epinephine secreting and demonstrate bilateral adrenal involvement, and is less likely to be malignant. The diagnosis of PC requires clinical suspicion and biochemical testing, followed by imaging studies. Novel nuclear medicine modalities, including FDG positron emission tomography (PET) and 68Ga DOTATATE PET have added to the conventional techniques of 123I-metaiodobenzylguanindine (MIBG) scintigraphy, computer tomography and magnetic resonance imaging. Treatment of PC is surgical and requires peri-operative alpha and, frequently, beta blockade. Novel surgical techniques, such as adrenal sparing surgery and a laparoscopic approach, have decreased peri-operative morbidity. Surveillance for PC is life long, due to the risk of metastatic disease.

Genetic testing in the clinical care of patients with pheochromocytoma and paraganglioma

PURPOSE OF REVIEW

Paraganglioma and pheochromocytoma (PGL/PCC) are tumours of neural crest origin that can present along a clinical spectrum ranging from apparently sporadic, isolated tumours to a more complex phenotype of one or multiple tumours in the context of other clinical features and family history suggestive of a defined hereditary syndrome. Genetic testing for hereditary PGL/PCC can help to confirm a genetic diagnosis for sporadic and syndromic cases. Informative genetic testing serves to clarify future risks for the patient and family members.

RECENT FINDINGS

Genetic discovery in the last decade has identified new PGL/PCC susceptibility loci. We summarize a contemporary approach adopted in our programme for genetic evaluation, testing and prospective management involving biochemical monitoring and imaging for hereditary PGL/PCC. A clinical vignette is presented to illustrate our practice.

SUMMARY

Current estimates that up to 40% of PGL/PCC are associated with germline mutations have implications for genetic testing recommendations. Prospective management of patients with defined hereditary susceptibility is based on established guidelines for well characterized syndromes. Management of tumour risk for rare syndromes, newly defined genetic associations and undefined genetic susceptibility in the setting of significant family history presents a challenge. Sustained discovery of new PGL/PCC genes underscores the need for a practice of continued genetic evaluation for patients with uninformative results. All patients with PGL/PCC should undergo genetic testing to identify potential hereditary tumour susceptibility.

Paragangliomas/Pheochromocytomas: clinically oriented genetic testing

Paragangliomas are rare neuroendocrine tumors that arise in the sympathetic or parasympathetic nervous system. Sympathetic paragangliomas are mainly found in the adrenal medulla (designated pheochromocytomas) but may also have a thoracic, abdominal, or pelvic localization. Parasympathetic paragangliomas are generally located at the head or neck. Knowledge concerning the familial forms of paragangliomas has greatly improved in recent years. Additionally to the genes involved in the classical syndromic forms: VHL gene (von Hippel-Lindau), RET gene (Multiple Endocrine Neoplasia type 2), and NF1 gene (Neurofibromatosis type 1), 10 novel genes have so far been implicated in the occurrence of paragangliomas/pheochromocytomas: SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, MAX, EGLN1, HIF2A, and KIF1B. It is currently accepted that about 35% of the paragangliomas cases are due to germline mutations in one of these genes. Furthermore, somatic mutations of RET, VHL, NF1, MAX, HIF2A, and H-RAS can also be detected. The identification of the mutation responsible for the paraganglioma/pheochromocytoma phenotype in a patient may be crucial in determining the treatment and allowing specific follow-up guidelines, ultimately leading to a better prognosis. Herein, we summarize the most relevant aspects regarding the genetics and clinical aspects of the syndromic and nonsyndromic forms of pheochromocytoma/paraganglioma aiming to provide an algorithm for genetic testing.

Hypoxia-inducible factor signaling in pheochromocytoma: turning the rudder in the right direction

Many solid tumors, including pheochromocytoma (PHEO) and paraganglioma (PGL), are characterized by a (pseudo)hypoxic signature. (Pseudo)hypoxia has been shown to promote both tumor progression and resistance to therapy. The major mediators of the transcriptional hypoxic response are hypoxia-inducible factors (HIFs). High levels of HIFs lead to transcription of hypoxia-responsive genes, which are involved in tumorigenesis. PHEOs and PGLs are catecholamine-producing tumors arising from sympathetic- or parasympathetic-derived chromaffin tissue. In recent years, substantial progress has been made in understanding the metabolic disturbances present in PHEO and PGL, especially because of the identification of some disease-susceptibility genes. To date, fifteen PHEO and PGL susceptibility genes have been identified. Based on the main transcription signatures of the mutated genes, PHEOs and PGLs have been divided into two clusters, pseudohypoxic cluster 1 and cluster 2, rich in kinase receptor signaling and protein translation pathways. Although these two clusters seem to show distinct signaling pathways, recent data suggest that both clusters are interconnected by HIF signaling as the important driver in their tumorigenesis, and mutations in most PHEO and PGL susceptibility genes seem to affect HIF-α regulation and its downstream signaling pathways. HIF signaling appears to play an important role in the development and growth of PHEOs and PGLs, which could suggest new therapeutic approaches for the treatment of these tumors.

Pheochromocytoma in an 8-year-old patient with multiple endocrine neoplasia type 2A: implications for screening

Childhood pheochromocytoma in the setting of multiple endocrine neoplasia type 2 (MEN2) remains rare and has not been reported under the age of 12. We present an 8-year-old female with known MEN 2A, C634Y RET mutation, diagnosed with a 6 cm pheochromocytoma requiring laparoscopic adrenalectomy. Given this patient's age at diagnosis, screening guidelines should recommend annual screening beginning at age 8 for patients with MEN 2B or MEN 2A codons 630 or 634 RET mutations.

[Medullary thyroid carcinoma in children]

Medullary thyroid carcinoma (MTC) is rare in children. MTC is almost always inherited and occurs as part of a multiple endocrine neoplasia type 2A and B, due to germline mutation in the RET proto-oncogene. MTC in the pediatric population is most often diagnosed in the course of a familial genetic investigation. But when the child is the proband, a de novo mutation is most often founded. The main aim is to treat MTC before extrathyroidal extension occurs because when distant metastases are present, it is rarely curable. Treatment is based on total thyroidectomy with cervical lymph node dissection.

High penetrance of pheochromocytoma in multiple endocrine neoplasia 2 caused by germ line RET codon 634 mutation in Japanese patients

OBJECTIVE

The precise penetrance of pheochromocytoma (PHEO) in multiple endocrine neoplasia type 2 (MEN2) has not been reported in a large cohort. In this study, we aimed to clarify the codon-specific penetrance of PHEO in MEN2.

DESIGN

We established a study group designated the 'MEN Consortium of Japan' in 2008 and asked physicians and surgeons to provide clinical and genetic information on patients they had treated up to 2011.

METHODS

Data were collected on patients identified as carriers of the RET mutation or diagnosed with medullary thyroid carcinoma (MTC) and/or PHEO with family history from 52 institutions all over Japan.

RESULTS

Of 493 registered MEN2 patients, RET mutation data were available for 390. Of these, 144 developed PHEOs, while 246 did not. The penetrance of PHEO was 25% by age 30 years, 52% by age 50 years, and 88% by age 77 years in RET mutation carriers with a codon 634 mutation. All patients with a codon 918 mutation (MEN2B) developed PHEO by age 56 years. Less than 32%penetrance of PHEO was seen in patients with mutations at codons other than 634 and 918.

CONCLUSIONS

Most patients with a codon 634 mutation develop PHEOs as well as MTC during their lifetime.

Pheochromocytoma: the range of appearances on ultrasound, CT, MRI, and functional imaging

OBJECTIVE

Pheochromocytomas are relatively rare neuroendocrine tumors of the adrenal medulla. Their variable clinical presentation and biologic behavior often make accurate diagnosis challenging. A variable spectrum of imaging appearances--some of which may also mimic other diseases--has been recognized. This article reviews the epidemiology; associations; and clinical, biochemical, pathologic, and multimodality imaging features of pheochromocytomas including diagnostic pearls and pitfalls.

CONCLUSION

Pheochromocytomas are often considered the great mimicker of other adrenal tumors. Because of their varied clinical, imaging, and pathologic appearances, accurate diagnosis can be challenging. The various imaging appearances on ultrasound, CT, MRI, and functional imaging can be complementary and have features that are useful for differentiating pheochromocytoma from other lesions of the adrenal.

Clinical experience with pheochromocytoma in a single centre over 16 years

BACKGROUND

Pheochromocytoma and paraganglioma are rare tumours of neuroectodermal origin. Pheochromocytoma occurs in 0.1-2% of people with hypertension, while the incidence rises to 4-5% in patients with incidental adrenal mass.

AIM

To analyse the presentation, diagnosis and localization, pathology, molecular genetic aspects, surgical management and long-term outcome of a large series of patients with pheochromocytoma referred to a single centre.

METHODS

From 1992 to 2008, we observed 91 patients with pheochromocytoma, 70 (77%) with the sporadic form and 21 (23%) with the hereditary form. In the group with the hereditary form, the mean age at diagnosis was significantly lower than the mean age of the group with the sporadic form (38 vs 48 years; p < 0.001).

RESULTS

Eighty (88%) patients with pheochromocytoma were symptomatic and the classical triad of palpitations, headache and diaphoresis was present in 30% of patients. In 12% of patients, the pheochromocytoma was discovered during radiological images (adrenal incidentaloma). The unilateral adrenal localization was observed in 78% of patients, bilateral in 15% and extra-adrenal in 7% of patients. All pheochromocytoma patients underwent surgical procedure and the laparotomic approach was used in 49 (53%) patients, while the laparoscopic approach was performed in 42 (47%) patients. Pheochromocytoma was benign in 86 patients (93%) [mean size was 4.3 cm] and the malignant form was found in five patients (7%) [mean size was 10 cm].

CONCLUSIONS

These data from a large cohort of patients are consistent with those reported in the literature and show that pheochromocytoma is an in important challenge for clinicians.

Diagnosis of silent pheochromocytoma and paraganglioma

Pheochromocytomas or functioning paragangliomas can present in a dramatic manner with headache, palpitations and sometimes shock, but many occur with few symptoms despite at times markedly elevated catecholamine levels. Hypertension is not invariable, and may be paroxysmal. Increased diligence in the diagnosis of presymptomatic pheochromocytoma/paraganglioma is warranted from autopsy studies, suggesting that many of these tumors may be fatal at first presentation. Fortunately, an increasing number of pheochromocytomas/paragangliomas are now diagnosed before the advent of symptoms, either as an incidental finding on abdominal imaging or by targeted surveillance in subjects with known genetic susceptibility. The challenges and pitfalls associated with diagnosis of these silent pheochromocytoma/paragangliomas are reviewed in this article.

Pheochromocytoma and paraganglioma: understanding the complexities of the genetic background

Pheochromocytomas and paragangliomas (PCC/PGL) are tumors derived from the adrenal medulla or extra-adrenal ganglia, respectively. They are rare and often benign tumors that are associated with high morbidity and mortality due to mass effect and high circulating catecholamines. Although most PCCs and PGLs are thought to be sporadic, over one third are associated with 10 known susceptibility genes. Mutations in three genes causing well characterized tumor syndromes are associated with an increased risk of developing PCCs and PGLs, including VHL (von Hippel-Lindau disease), NF1 (Neurofibromatosis Type 1), and RET (Multiple Endocrine Neoplasia Type 2). Mutations in any of the succinate dehydrogenase (SDH) complex subunit genes (SDHA, SDHB, SDHC, SDHD) can lead to PCCs and PGLs with variable penetrance, as can mutations in the subunit cofactor, SDHAF2. Recently, two additional genes have been identified, TMEM127 and MAX. Although these tumors are rare in the general population, occurring in two to eight per million people, they are more commonly associated with an inherited mutation than any other cancer type. This review summarizes the known germline and somatic mutations leading to the development of PCC and PGL, as well as biochemical profiling for PCCs/PGLs and screening of mutation carriers.

Unilateral subtotal adrenalectomy for pheochromocytoma in multiple endocrine neoplasia type 2 patients: a feasible surgical strategy

OBJECTIVE

To determine the best surgical strategy for pheochromocytoma in multiple endocrine neoplasia type 2 (MEN2) patients.

BACKGROUND

Pheochromocytomas occur in 50% to 60% of MEN2 patients, approximately half of them eventually develop bilateral disease. Unilateral subtotal adrenalectomy as primary surgery for pheochromocytoma in these patients may avoid or postpone the need for corticosteroid replacement therapy and the risk of Addisonian crisis, but is not yet widely accepted.

METHODS

We conducted a retrospective cohort study including 61 MEN2 patients with pheochromocytoma who were treated at the University Medical Center Utrecht between 1959 and 2010. Surgery was classified into 4 adrenalectomy groups: bilateral total, unilateral total, bilateral subtotal, and unilateral subtotal.

RESULTS

Primary surgery involved 22 bilateral total, 30 unilateral total, 2 bilateral subtotal, and 7 unilateral subtotal adrenalectomies. Twenty-one patients developed ipsilateral or contralateral recurrence after a median follow-up of 13.4 ± 10.8 years (range: 0.1-41.8). Unilateral total and unilateral subtotal adrenalectomy had similar rates of recurrence (P = 0.232) and survival time (5.5 versus 8.8 years; P = 0.170). Steroid replacement after bilateral total adrenalectomy led to complications in 8 patients. Reoperations for recurrence included unilateral total adrenalectomy in 12 patients, after which 10 needed steroid replacement (with complications in 3) and unilateral subtotal adrenalectomy in 5 patients, after which none needed replacement therapy. Ipsilateral recurrence after reoperation was similar between these groups.

CONCLUSIONS

Unilateral subtotal adrenalectomy is a feasible surgical strategy for pheochromocytoma in MEN2 patients. It has comparable recurrence rates and eventually less complications of steroid replacement compared to unilateral total adrenalectomy.

Genetics and clinical characteristics of hereditary pheochromocytomas and paragangliomas

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare neuroendocrine tumors of the adrenal glands and the sympathetic and parasympathetic paraganglia. They can occur sporadically or as a part of different hereditary tumor syndromes. About 30% of PCCs and PGLs are currently believed to be caused by germline mutations and several novel susceptibility genes have recently been discovered. The clinical presentation, including localization, malignant potential, and age of onset, varies depending on the genetic background of the tumors. By reviewing more than 1700 reported cases of hereditary PCC and PGL, a thorough summary of the genetics and clinical features of these tumors is given, both as part of the classical syndromes such as multiple endocrine neoplasia type 2 (MEN2), von Hippel-Lindau disease, neurofibromatosis type 1, and succinate dehydrogenase-related PCC-PGL and within syndromes associated with a smaller fraction of PCCs/PGLs, such as Carney triad, Carney-Stratakis syndrome, and MEN1. The review also covers the most recently discovered susceptibility genes including KIF1Bβ, EGLN1/PHD2, SDHAF2, TMEM127, SDHA, and MAX, as well as a comparison with the sporadic form. Further, the latest advances in elucidating the cellular pathways involved in PCC and PGL development are discussed in detail. Finally, an algorithm for genetic testing in patients with PCC and PGL is proposed.

Malignant pheochromocytomas and paragangliomas: a diagnostic challenge

INTRODUCTION

Malignant pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare disorders arising from the adrenal gland, from the glomera along parasympathetic nerves or from paraganglia along the sympathetic trunk. According to the WHO classification, malignancy of PCCs and PGLs is defined by the presence of metastases at non-chromaffin sites distant from that of the primary tumor and not by local invasion. The overall prognosis of metastasized PCCs/PGLs is poor. Surgery offers currently the only change of cure. Preferably, the discrimination between malignant and benign PCCs/PGLs should be made preoperatively.

METHODS

This review summarizes our current knowledge on how benign and malignant tumors can be distinguished.

CONCLUSION

Due to the rarity of malignant PCCs/PGLs and the obvious difficulties in distinguishing benign and malignant PCCs/PGLs, any patient with a PCC/PGL should be treated in a specialized center where a multidisciplinary setting with specialized teams consisting of radiologists, endocrinologist, oncologists, pathologists and surgeons is available. This would also facilitate future studies to address the existing diagnostic and/or therapeutic obstacles.

Management of medullary thyroid carcinoma and MEN2 syndromes in childhood

Medullary thyroid carcinoma (MTC) and the multiple endocrine neoplasia (MEN) type 2 syndromes are rare but important endocrine diseases that are increasingly managed by pediatric providers. MTC is generally associated with a favorable prognosis when diagnosed during childhood, where it frequently occurs secondary to activating mutations in the RET proto-oncogene and arises from pre-existing C-cell hyperplasia. MEN2A accounts for 90-95% of childhood MTC cases and is most commonly due to mutations in codon 634 of RET. MEN2B is associated with the most aggressive clinical presentation of MTC and is almost always due to the Met918Thr mutation of RET. Surgery is the primary treatment and only chance of cure, although the advent of targeted therapies seems to be improving progression-free survival in advanced cases. Since the discovery of the role of RET in MEN2A, considerable advances in the management of this syndrome have occurred, and most of the children with MEN2A who have undergone early thyroidectomy will now lead full, productive lives. Strong genotype-phenotype correlations have facilitated the development of guidelines for interventions. Contemporary approaches for deciding the appropriate age at which surgery should take place incorporate data from ultrasonography and calcitonin measurements in addition to the results of genotyping. To optimize care and to facilitate ongoing research, children with MTC and the MEN2 syndromes are optimally treated at tertiary centers with multidisciplinary expertise.

Spontaneous adrenal pheochromocytoma rupture complicated by intraperitoneal hemorrhage and shock

MEN2A is a hereditary syndrome characterized by medullary thyroid carcinoma, hyperparathyroidism, and pheochromocytoma. Classically patients with a pheochromocytoma initially present with the triad of paroxysmal headaches, palpitations, and diaphoresis accompanied by marked hypertension. However, although reported as a rare presentation, spontaneous hemorrhage within a pheochromocytoma can present as an abdominal catastrophe. Unrecognized, this transformation can rapidly result in death. We report the only documented case of a thirty eight year old gentleman with MEN2A who presented to a community hospital with hemorrhagic shock and peritonitis secondary to an unrecognized hemorrhagic pheochromocytoma. The clinical course is notable for an inability to localize the source of hemorrhage during an initial damage control laparotomy that stabilized the patient sufficiently to allow emergent transfer to our facility, re-exploration for continued hemorrhage and abdominal compartment syndrome, and ultimately angiographic embolization of the left adrenal artery for control of the bleeding. Following recovery from his critical illness and appropriate medical management for pheochromocytoma, he returned for interval bilateral adrenal gland resection, from which his recovery was unremarkable. Our review of the literature highlights the high mortality associated with the undertaking of an operative intervention in the face of an unrecognized functional pheochromocytoma. This reinforces the need for maintaining a high index of suspicion for pheochromocytoma in similar cases. Our case also demonstrates the need for a mutimodal treatment approach that will often be required in these cases.

Diagnosis of multiple endocrine neoplasia type 2A in patients with positive thyroid imaging by iodine-131 metaiodobenzylguanidine scintigraphy

We retrospectively analyzed iodine-131 metaiodobenzylguanidine (I-131 MIBG) scintigraphy in 320 patients (male, 108 cases; female, 211 cases; average age, 45±15 years). All patients received thyroid block before examination between 2007 and 2010 in our department. Various degrees of radioactivity were found in the thyroid glands or thyroid region after bilateral thyroid surgery, in addition to bilateral or unilateral abnormal radioactivity in the adrenal glands in 3 patients. These cases were confirmed for medullary thyroid carcinoma and adrenal pheochromocytoma by pathology after surgical removal of the glands, and the diagnosis of multiple endocrine neoplasia type 2A was established from the patients' history and genetic examination. The possibility of medullary thyroid carcinoma should be considered on the finding of abnormal radioactivity in the thyroid or thyroid region by I-131 MIBG scintigraphy after excluding normal radioactivity in the thyroid. When significant abnormal radioactivity is seen in the adrenal gland on I-131 MIBG scintigraphy, the possibility of adrenal pheochromocytoma should be considered. Adrenal pheochromocytoma cannot be excluded when adrenal uptake is increased. The possibility of multiple endocrine neoplasia type 2A should be considered taking into account the history of these patients.

Medullary thyroid carcinoma: The third most common thyroid cancer reviewed

Medullary thyroid cancer is a type of thyroid cancer of neuroendocrine origin. It occurs in hereditary and sporadic forms, and its aggressive behavior is associated with the clinical presentation and type of RET mutation. Total thyroidectomy remains the ideal choice of treatment. Early diagnosis and treatment are the fundamental for a 100% cure rate. In this study, we present our experience of 3 cases, along with a complete review of the literature derived from a Pubmed Database search.

Phaeochromocytomas and sympathetic paragangliomas

BACKGROUND

About 24 per cent of phaeochromocytomas (PCCs) and sympathetic paragangliomas (sPGLs) appear in familial cancer syndromes, including multiple endocrine neoplasia type 2, von Hippel-Lindau disease, neurofibromatosis type 1 and PCC-paraganglioma syndrome. Identification of these syndromes is of prime importance for patients and their relatives. Surgical resection is the treatment of choice for both PCC and sPGL, but controversy exists about the management of patients with bilateral or multiple tumours.

METHODS

Relevant medical literature from PubMed, Ovid and Embase websites until 2009 was reviewed for articles on PCC, sPGL, hereditary syndromes and their treatment.

DISCUSSION

Genetic testing for these syndromes should become routine clinical practice for those with PCC or sPGL. Patients should be referred to a clinical geneticist. Patients and family members with proven mutations should be entered into a standardized screening protocol. The preferred treatment of PCC and PGL is surgical resection; to avoid the lifelong consequences of bilateral adrenalectomy, cortex-sparing adrenalectomy is the treatment of choice.

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

Multiple endocrine neoplasia syndrome type 1 (MEN-1) consists of endocrine tumors of the parathyroid, the endocrine pancreas-duodenum, and the pituitary. Surveillance and screening for the endocrinopathies is recommended in gene carriers. Surgery for MEN-1-related hyperparathyroidism is generally performed as radical subtotal parathyroidectomy, because less surgery is likely to result in persistent or recurrent disease. Multiple endocrine neoplasia syndrome type 2 (MEN-2) consists of medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism. Prophylactic thyroidectomy based on DNA testing in the MEN-2 syndrome is considered one of the greater achievements in cancer treatment, because it may be performed before thyroid carcinoma development and provides cure for the patient.

Palliation of advanced thyroid malignancies

While most thyroid cancers are slow-growing and have an excellent prognosis after appropriate treatment, a subset of thyroid cancers behave aggressively, and approximately 1500 individuals in the US will die of the disease in the year 2007. Advanced thyroid malignancies can cause distressing and life-threatening symptoms by local invasion in the neck, growth of distant metastases in the lung, bone, and other organs, and tumor production of bioactive substances in the case of medullary thyroid cancer. This article will review palliative modalities, including surgery, radioactive iodine, external beam radiation, and chemotherapy, as well as novel targeted therapies, for the treatment of patients with advanced thyroid malignancies.

Clinical review: Current treatment of malignant pheochromocytoma

CONTEXT

Pheochromocytomas are rare tumors of predominantly adrenal origin that often produce and secrete catecholamines. Malignancy occurs in a variable percentage of cases depending on genetic background and tumor location. Definitive diagnosis relies on the detection of distant metastases. Treatments for malignant pheochromocytoma include surgical debulking, pharmacological control of hormone-mediated symptoms, targeted methods such as external irradiation, and systemic antineoplastic therapy. Different agents and protocols for this purpose are reviewed, and their therapeutic potential is discussed.

EVIDENCE ACQUISITION

Literature on antineoplastic therapies for malignant pheochromocytoma was identified by searching the PubMed database with restriction to articles published in English during the past 30 yr.

EVIDENCE SYNTHESIS

Because of the rarity of the condition, no randomized clinical trials concerning the treatment of malignant pheochromocytoma have been performed. The strategy established best is [131I]meta-iodobenzylguanidine (MIBG) therapy, which is well tolerated. Similar to cytotoxic chemotherapy with cyclophosphamide, vincristine, and dacarbazine, MIBG can induce remission for a limited period in a significant proportion of patients. Octreotide as a single agent seems to be largely ineffective.

CONCLUSIONS

MIBG radiotherapy and cyclophosphamide, vincristine, and dacarbazine chemotherapy are comparable with respect to response rate and toxicity. It is unclear whether combining both can improve the outcome. Future developments may include new multimodal concepts with focus on inhibition of angiogenetic factors and heat shock protein 90. Any present or new therapeutic approach must take into account the highly variable natural course of the disease.

Initial Lymph Node Dissection Increases Cure Rates in Patients with Medullary Thyroid Cancer

OBJECTIVE

Medullary thyroid carcinoma (MTC) is the third most common type of thyroid cancer. MTC spreads early to local lymph nodes, and most endocrine surgeons recommend total thyroidectomy with central lymph node dissection (CLND) as the minimum initial operation. We reviewed our experience to determine if the initial operation influences clinical outcomes.

METHODS

Twenty-two patients with sporadic or inherited MTC who received surgery at one academic centre between 1994 and 2004 were identified. Clinical, operative, and pathology findings were reviewed.

RESULTS

Ten patients had prophylactic thyroidectomy for hereditary MTC, while 12 patients underwent therapeutic operations for sporadic MTC. The average age of the prophylactic group was 11 +/- 3, and 43 +/- 6 years for the therapeutic group. All patients in the prophylactic group received thyroidectomy without neck dissection. No patient in the prophylactic group had residual disease or required re-operation. In the therapeutic surgery group, three patients were treated with thyroidectomy plus CLND, and nine patients received thyroidectomy alone. The CLND group had a significantly higher cure rate as demonstrated by a lower incidence of residual disease (0% vs. 89%, p = 0.018), and re-operations (0% vs. 78%, p = 0.045).

CONCLUSION

Initial CLND for MTC increases cure rates by reducing residual disease and re-operations.