The North American Neuroendocrine Tumor Society consensus guideline for the diagnosis and management of neuroendocrine tumors: pheochromocytoma, paraganglioma, and medullary thyroid cancer

Genotypic characteristics and their association with phenotypic characteristics of hereditary medullary thyroid carcinoma in Korea

BACKGROUND

Hereditary medullary thyroid carcinoma can present as a part of multiple endocrine neoplasia syndrome by rearranged during transfection gene mutation. We evaluated the prevalence of rearranged during transfection gene mutation in patients who have medullary thyroid carcinoma and the correlations of genotype with medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism according to the revised American Thyroid Association risk level.

METHODS

A total of 331 patients were diagnosed with medullary thyroid carcinoma, 172 of whom were tested for the rearranged during transfection germline mutation by sequencing of exon 8, 10, 11, and 13-16. These patients were diagnosed during the years 1982-2012 at 2 Korean tertiary hospitals. Patients were analyzed according to the route of diagnosis (screened versus index cases) or the mutational site of rearranged during transfection gene (the American Thyroid Association risk group).

RESULTS

Rearranged during transfection mutation was found in 23.8% of patients tested, showing a decreasing trend with time. The most commonly mutated codon was codon 634 (37.1%), followed by codon 918 (14.3%). rearranged during transfection-positive patients were younger than rearranged during transfection-negative patients, although no other clinicopathologic characteristics differed. Screened cases were younger and had smaller tumors than index cases. Among rearranged during transfection-positive patients, pheochromocytoma manifested in 35.1% and hyperparathyroidism in 7.0%. Notably, pheochromocytoma and hyperparathyroidism emerged at any time after the diagnosis of medullary thyroid carcinoma. The American Thyroid Association risk-group analysis demonstrated that medullary thyroid carcinoma patients in the highest risk group were younger, had larger tumors, and higher disease-specific mortality. Similar results for pheochromocytoma were found, according to the American Thyroid Association risk group, although the results were not significant.

CONCLUSIONS

Korean patients who have medullary thyroid carcinoma showed a similar distribution of rearranged during transfection gene mutation with those in Western countries. The American Thyroid Association risk classification was shown to be useful for pheochromocytoma, as well as for medullary thyroid carcinoma. Familial screening for rearranged during transfection mutation and lifelong monitoring for associated pheochromocytoma should be emphasized in hereditary medullary thyroid carcinoma.

Bilaterally enlarged adrenal glands without obvious cause: need for a multidisciplinary diagnostic work-up

Bilateral enlarged adrenal glands are rare, and as diagnostic delay may have serious consequences for the patient, we recommend a multidisciplinary approach of specialists in the field of endocrinology, oncology, radiology, and clinical chemistry prior to the start of the diagnostic work‐up.

Efficacy and safety of metyrosine in pheochromocytoma/paraganglioma: a multi-center trial in Japan

To assess the efficacy, safety, and pharmacokinetics of metyrosine (an inhibitor of catecholamine synthesis) in patients with pheochromocytoma/paraganglioma (PPGL), we conducted a prospective, multi-center, open-label study at 11 sites in Japan. We recruited PPGL patients aged ≥12 years requiring preoperative or chronic treatment, receiving α-blocker treatment, having baseline urinary metanephrine (uMN) or normetanephrine (uNMN) levels ≥3 times the upper limit of normal values, and having symptoms associated with excess catecholamine. Metyrosine treatment was started at 500 mg/day and modified according to dose-adjustment criteria up to 4,000 mg/day. The main outcome measure was the proportion of patients who achieved at least 50% reduction in uMN or uNMN levels from baseline. Sixteen patients (11 males/5 females) aged 12-86 years participated. After 12 weeks of treatment and at the last evaluation of efficacy, the primary endpoint was achieved in 31.3% of all patients, including 66.7% of those under preoperative treatment and 23.1% of those under chronic treatment. Sedation, anemia, and death were reported in 1 patient each as serious adverse drug reactions during the 24-week treatment. Metyrosine was shown to be tolerated and to relieve symptoms by reducing excess catecholamine in PPGL patients under both preoperative and chronic treatment.

Metastatic Pheochromocytoma in an Asymptomatic 12-Year-Old With von Hippel-Lindau Disease

Pheochromocytoma is a rare chromaffin cell tumor that may be associated with a genetic predisposition, such as von Hippel-Lindau (VHL) disease. VHL is an autosomal dominant disorder that is characterized by a predisposition to multiple tumors, including retinal and central nervous system hemangioblastomas, renal cell carcinoma, and pheochromocytomas. The classic presentation of pheochromocytoma is episodic hypertension, headaches, palpitations, and diaphoresis. In the pediatric population, 40% of pheochromocytomas have a hereditary basis. We present a case of metastatic pheochromocytoma in a child with VHL and discuss the relevant current medical literature.

Prevention of serious skeletal-related events by interventional radiology techniques in patients with malignant paraganglioma and pheochromocytoma

PURPOSE

Bone metastases (BM) and skeletal-related events (SRE) are frequent in patients with malignant pheochromocytoma and paraganglioma (PPM) and the best modality of prevention unknown. The role of interventional radiology (IR) techniques for the prevention of SRE in the multidisciplinary management of malignant PPM has not been evaluated in that setting.

METHODS

Single referral center retrospective review of all patients with malignant PPM with BM from 2000 to 2016. The primary endpoint was the time to first serious SRE (TTSRE). At time of inclusion, patients with high bone tumor burden disease were defined as those having more than five BM with the biggest exceeding 2 cm (Group A) and patients with moderate bone tumor burden disease were defined as those having five or less BM or no BM exceeding 2 cm (Group B).

RESULTS

A total of 28 patients were included in this study. Thirteen were treated by IR techniques for prevention of first serious SRE. After a median follow-up of 48.2 months, the median TTSRE was not reached in patients treated by IR techniques and was 26.0 months in patients without IR procedures (p = .058). When comparing patients in group B, TTSRE was significantly higher in patients treated by IR (10 patients) when compared to patients without IR procedures (12 patients) (p = .021).

CONCLUSIONS

IR techniques may help to delay the occurrence of first serious SRE in patients with malignant PPM with moderate bone tumor burden disease. Prospective studies are expected to confirm these results.

Combined epidural-general anesthesia was associated with lower risk of postoperative complications in patients undergoing open abdominal surgery for pheochromocytoma: A retrospective cohort study

Background

Current evidences show that regional anesthesia is associated with decreased risk of complications after major surgery. However, the effects of combined regional-general anesthesia remain controversial. The purpose of our study was to analyze the impact of anesthesia (combined epidural-general anesthesia vs. general anesthesia) on the risk of postoperative complications in patients undergoing open surgery for pheochromocytoma.

Methods

This was a retrospective cohort study. 146 patients who underwent open surgery for pheochromocytoma (100 received combined epidural-general anesthesia and 46 received general anesthesia) in Peking University First Hospital from January 1, 2002 to December 31, 2015 were enrolled. The primary outcome was the occurrence of postoperative complications during hospital stay after surgery. Multivariate Logistic regression models were used to analyze the association between the choice of anesthetic method and the risk of postoperative complications.

Results

17 (11.6%) patients developed complications during postoperative hospital stay. The incidence of postoperative complications was lower in patients with combined epidural-general anesthesia than in those with general anesthesia (6% [6/100] vs. 23.9% [11/46], P = 0.006). Multivariate Logistic regression analysis showed that use of combined epidural-general anesthesia (OR 0.219, 95% CI 0.065–0.741; P = 0.015) was associated with lower risk, whereas male gender (OR 5.213, 95% CI 1.283–21.177; P = 0.021) and perioperative blood transfusion (OR 25.879; 95% CI 3.130–213.961; P = 0.003) were associated with higher risk of postoperative complications.

Conclusions

For patients undergoing open surgery for pheochromocytoma, use of combined epidural-general anesthesia may decrease the occurrence of postoperative complications.

Current diagnostic imaging of pheochromocytomas and implications for therapeutic strategy

The topic of pheochromocytomas is becoming increasingly popular as a result of major advances in different medical fields, including laboratory diagnosis, genetics, therapy, and particularly in novel advances in imaging techniques. The present review article discusses current clinical, biochemical, genetic and histopathological aspects of the diagnosis of pheochromocytomas and planning of pre-surgical preparation and subsequent surgical treatment options. The main part of the paper is focused on the role of morphological imaging methods (primarily computed tomography and magnetic resonance imaging) and functional imaging (scintigraphy and positron emission tomography) in the diagnosis and staging of pheochromocytomas.

High specificity of spot urinary free metanephrines in diagnosis and prognosis of pheochromocytomas and paragangliomas by HPLC with electrochemical detection

BACKGROUND

The metanephrines (MNs) in plasma and urine were proposed as biomarkers for the diagnosis of pheochromocytomas and paragangliomas (PPGLs). However, plasma free MNs and 24h urinary fractionated MNs were not satisfactory enough in specificity for the diagnosis of PPGLs. Moreover, the collection of 24h urine was inconvenient. This work examined the diagnostic and prognostic efficiency of free MNs in spot urine for PPGLs.

METHODS

We measured free MNs concentration in spot urine and plasma of 28 PPGLs patients and 155 control subjects by HPLC with electrochemical detection. Postoperative free MNs levels in spot urine and plasma of 14 PPGLs patients were also determined. Creatinine (Cr) concentration was used for the correction of urine volume.

RESULTS

The specificity of spot urinary free MNs/Cr in the diagnosis of PPGLs was significantly higher than that of plasma free MNs [normetanephrine (NMN), 98.7% (95.4%-99.8%) vs 93.0% (87.4%-96.6%); metanephrine (MN), 93.6% (88.5%-96.9%) vs 84.5% (77.5%-90.0%)]. Meanwhile, the positive likelihood ratios for spot urinary free NMN/Cr and MN/Cr were 69.21 and 13.29, compared with 12.68 and 5.30 for plasma free NMN and MN, respectively. For the PPGLs patients underwent surgery, the plasma free MNs level appeared an abnormal elevation and yielded false-positive results for some patients. Our findings were validated in an independent cohort, resulting in the specificity of 100% for both urinary free NMN/Cr and MN/Cr, and 97.3% and 83.8% for plasma free NMN and MN, respectively.

CONCLUSIONS

Spot urinary free MNs/Cr, superior to plasma free MNs, presented a promising biomarker for the diagnosis and prognosis of PPGLs.

Survival in patients with medullary thyroid cancer after less than the recommended initial operation

BACKGROUND AND OBJECTIVES

We aimed to evaluate the disease specific-survival (DSS) of patients with Medullary Thyroid Cancer (MTC) confined to the central neck based on the extent of the initial operation.

METHODS

This retrospective review of patients with MTC from the SEER registry from 2004 to 2012 excluded patients with lateral neck involvement or distant metastases.

RESULTS

The cohort (n = 766) included 85(11%) less than total thyroidectomies (TT), 212(28%) TT alone, and 469(61%) TT with lymph node excision. Mean tumor size was similar (2.2cm for <TT, 1.9 for TT alone, and 2.2 for TT with nodes, p=0.13). Patients receiving a TT with nodal excision were more likely to have multifocal tumors (8% <TT, 22% TT alone, and 27% TT with nodes, P < 0.001), and extrathyroidal extension (1% <TT, 4% TT alone, and 9% TT with nodes, P = 0.005). Even after controlling for significant predictors of DSS, extent of the initial operation did not predict survival (HR 0.28 for <TT, 95% CI 0.26-3.11 and HR 0.62 for TT alone, 95% CI 0.17-2.22 compared to TT with nodes, P = NS for all).

CONCLUSION

According to population-based SEER registry data, the extent of initial resection may not significantly change DSS in patients with MTC confined to the central neck.

Somatostatin receptor subtype 1 might be a predictor of better response to therapy in medullary thyroid carcinoma

PURPOSE

Medullary thyroid carcinoma (MTC) is a malignant neoplasm of parafollicular cells. Because it is a neuroendocrine tumor, it has known somatostatin receptors (SSTRs). The actual frequencies of the SSTR subtypes and their potential influences (by binding with endogenous somatostatin) on MTC cell proliferation have not been fully elucidated to date. The present study evaluated the occurrence of SSTR subtypes 1, 2, 3 and 5 as well as the possible role that each subtype plays in the clinical evolution of patients with MTC.

METHODS

This retrospective, longitudinal study analyzed thyroid surgical material from 42 patients with MTC. Immunohistochemical staining was performed with monoclonal antibodies against subtypes 1, 2, 3 and 5 of SSTR. The histological material was classified as negative, focal positive or diffuse positive, in relation to each of the SSTR subtypes. The initial response to treatment, clinical course and patient mortality rate were assessed and related to the presence of SSTR subtypes.

RESULTS

The most prevalent SSTR subtype was SSTR 3, which was found in 81% of the patients, when considering any pattern of positivity. However, subtype 2 had the lowest number of positive patients, with 28.6% demonstrating any positive pattern. Subtypes 1 and 5 had an intermediate prevalence of positivity, with subtype 1 present in 45.2% of the patients and subtype 5 positive in 54.8% of the patients, when considering any pattern of positivity. The presence of STR 1, in the form of diffuse positivity, independently predicted a better response to the initial therapy, with a hazard ratio (HR) of 4.80 (p = 0.03).

CONCLUSION

This is the first study to show the correlation of the presence of SSTR1, detected by monoclonal immunohistochemical techniques, and better response to initial treatment and possibly better long-term clinical response in patients with MTC. In addition, these patients had low positivity rates for SSTR2, which might explain the low sensitivity of diagnostic and limited therapeutic response to octrotide based radioisotopes.

Anatomic Location is the Primary Determinant of Survival for Paragangliomas

Paragangliomas (PGL) are rare neuroendocrine tumors. This study describes the largest collection of PGLs and evaluates factors that impact survival. Patients with PGL from 1998 to 2013 in the NCDB were reviewed. Independent predictors of overall survival (OS) were identified for patients with non-central nervous system (CNS) tumors. Of 867 PGLs, the primary site was CNS (39.9%), abdomen/pelvis (A&P) (21.0%), head and neck (H&N) (17.5%), thoracic (15.1%), bladder (3%), or unspecified (3.5%). Of 521 non-central nervous system (CNS) PGLs, there were differences in sex, comorbidities, treatment facility, tumor size, treatment modality (P < 0.001). Five-year OS for this cohort was 66 per cent and 10-year OS was 51 per cent. Median OS differed significantly between primary sites (H&N 106.0 months, thoracic 89.0 months, A&P 81.7 months, bladder 69.7 months, and unspecified 27.2, P < 0.001). After controlling for multiple factors, age greater than 50 (HR 1.97; CI 1.38–2.81), primary site A&P (HR 2.01; CI) 1.17–3.48) or bladder (HR 4.03; CI 1.64–9.89) as compared with H&N, distant metastasis (HR 2.25; CI 1.44–3.53) and those who did not receive surgery (HR 2.85; CI 1.89–4.31) all exhibited decreased OS. This is the largest series of PGLs and the first to demonstrate significant survival differences based on PGL site. Abdominal/pelvic and bladder PGLs had the lowest survival in addition to patients that did not have a surgical resection, those with distant metastases, and >50 years of age.

Parotid metastases from thyroid carcinomas

Parotid metastases (PMs) that originate from thyroid carcinomas (TCs) are extremely rare, and many questions about their diagnosis and management remain unanswered. Of the 15,780 patients with TC that we had prospectively recorded in our institutional databases between 1996 and 2015, we retrospectively retrieved only three patients (0.019%) with PM. Patient characteristics, histological findings on initial thyroidectomy and parotidectomy specimens, treatments, and times of recurrence and death were reviewed. In addition, we searched PubMed, Embase, and ISI Web of Science databases (1996-2015) for articles published in the English language using the key words "parotid" and "thyroid", and reviewed almost all reports that described PM that were derived from TC. These rare cases of thyroid carcinoma presenting as metastasis in the parotid gland highlight the importance of maintaining close communication between clinicians, radiologists, and histopathologists to ensure that such rare cases are not missed.

All in the family? Analyzing the impact of family history in addition to genotype on medullary thyroid carcinoma aggressiveness in MEN2A patients

Several guidelines for patients with multiple endocrine neoplasia 2A (MEN2A) take into account genotype and family history of medullary thyroid carcinoma (MTC) disease aggressiveness. We sought to determine if an association exists independent of genotype, which could provide important information for counseling MEN2A patients in management of their MTC. Pedigrees of patients with ≥5 family members with MEN2A were retrospectively reviewed. Analysis was performed among kindreds with the most frequently observed codon mutation (RET 634). Familial MTC disease aggressiveness was evaluated using: (1) mean age at diagnosis of MTC, (2) current mean age of carriers without MTC, (3) proportion of kindred with MTC with metastatic disease at diagnosis, (4) proportion of kindred with MTC with metastasis/death from MTC as worst outcome, and (5) proportion of kindred with disease progression. 170 affected patients from 12 different MEN2A kindreds met inclusion criteria. The number of affected family members available for study per kindred ranged from 8 to 43 individuals. A difference in mean age of MTC diagnosis was found in screened patients (p = 0.01); mean age of MTC-free patients did not differ (p = 0.93). No differences were noted among kindreds in disease stage at presentation, worst outcome, or progression; marked variation in these measures was noted within families. In conclusion, a difference in age of MTC diagnosis among different RET 634 kindreds was identified. In contrast, notable intra-familial variability in disease aggressiveness was observed. Based on these findings, we recommend counseling patients with codon 634 mutations that their MTC disease course cannot be predicted by that of their relatives.

Genetic mechanisms of human hypertension and their implications for blood pressure physiology

Hypertension, or elevated blood pressure, constitutes a major public health burden that affects more than 1 billion people worldwide and contributes to ~9 million deaths annually. Hereditary factors are thought to contribute to up to 50% of interindividual blood pressure variability. Blood pressure in the general population approximately shows a normal distribution and is thought to be a polygenic trait. In rare cases, early-onset hypertension or hypotension are inherited as Mendelian traits. The identification of the underlying Mendelian genes and variants has contributed to our understanding of the physiology of blood pressure regulation, emphasizing renal salt handling and the renin angiotensin aldosterone system as players in the determination of blood pressure. Genome-wide association studies (GWAS) have revealed more than 100 variants that are associated with blood pressure, typically with small effect sizes, which cumulatively explain ~3.5% of blood pressure trait variability. Several GWAS associations point to a role of the vasculature in the pathogenesis of hypertension. Despite these advances, the majority of the genetic contributors to blood pressure regulation are currently unknown; whether large-scale exome or genome sequencing studies will unravel these factors remains to be determined.

Clinical Predictors of Malignancy in Patients with Pheochromocytoma and Paraganglioma

BACKGROUND AND PURPOSE

Factors associated with malignancy in patients with pheochromocytoma (adrenal tumors, Pheo) and paraganglioma (extra-adrenal, PGL) are not well-defined and all patients require lifelong surveillance. The primary aim of our study was to determine genetic and clinical variables associated with malignancy in patients with Pheo/PGL.

METHODS

Single institution retrospective review was performed of all patients who underwent surgery (1/95-1/15) for Pheo/PGL. Malignancy was defined as histology-confirmed distant metastasis, lymph nodal involvement, or tumor bed recurrence.

RESULTS

A total of 157 Pheo/PGL patients (44 malignant, 113 benign) with mean follow-up of 87 months were included. Compared with patients with benign Pheo/PGL, patients with malignant Pheo/PGL were younger (median 42 vs 50 years, p = 0.014), had larger tumors (median 6.5 vs 4 cm, p < 0.001) and had PGL (63.6 vs 4.4%, p < 0.001). Genetic testing was performed in 60 patients and was positive in 38 (63%). Although positive genetic results were equally likely in malignant vs benign Pheo/PGL (76 vs 54%, p = 0.1), all 11 patients with germline SDHB mutations had malignant disease. In multivariable analysis, younger age, larger tumor size, and PGL were associated with malignancy (p < 0.05). Pheo patients with negative genetic testing and negative family history who developed metachronous metastases all had primary tumors ≥4 cm in size.

CONCLUSIONS

Patients who are young, have larger tumors, positive genetic testing (especially SDHB) or have PGL require long-term follow-up. Patients with negative genetic testing or family history and Pheo <4 cm have a lower risk of malignancy, and de-escalated long-term surveillance may be appropriate follow-up.

Malignant Pheochromocytoma and Paraganglioma: 272 Patients Over 55 Years

CONTEXT

Malignant pheochromocytoma (PHEO) and paraganglioma (PGL) are rare and knowledge of the natural history is limited.

OBJECTIVE

We aimed to describe baseline characteristics and outcomes of patients with malignant PHEO and PGL (PPGL) and to identify predictors of shorter survival.

DESIGN

Retrospective review of patients with malignant PPGL evaluated from 1960 to 2016.

SETTING

Referral center.

PATIENTS

The group comprised 272 patients.

MAIN OUTCOME MEASURES

Baseline description, survival outcomes, and predictors of shorter survival were evaluated in patients with rapidly progressive (n = 29) and indolent disease (n = 188).

RESULTS

Malignant PPGL was diagnosed at a median age of 39 years (range, 7 to 83 years), with synchronous metastases in 96 (35%) patients. In 176 (65%) patients, metastases developed at a median of 5.5 years (range, 0.3 to 53.4 years) from the initial diagnosis. Median follow-up was 8.2 years (range, 0.01 to 54.1 years). Median overall and disease-specific survivals were 24.6 and 33.7 years, respectively. Shorter survival correlated with male sex (P = 0.014), older age at the time of primary tumor (P = 0.0011), synchronous metastases (P < 0.0001), larger primary tumor size (P = 0.0039), elevated dopamine (P = 0.0195), and not undergoing primary tumor resection (P < 0.0001). There was no difference in the type of primary tumor or presence of SDHB mutation.

CONCLUSIONS

The clinical course of patients with malignant PPGL is remarkably variable. Rapid disease progression is associated with male sex, older age at diagnosis, synchronous metastases, larger tumor size, elevated dopamine, and not undergoing resection of primary tumor. An individualized approach to patients with metastatic PPGL is warranted.

A Giant Adrenal Mass in a Super Obese Patient

Giant pheochromocytomas (Pheo) are rare entities requiring clinical suspicion coupled with strategic diagnostic evaluation to confirm the diagnosis. The majority of cases are discovered incidentally. The diagnosis consists of biochemical evaluation and imaging study to localize the mass. Pathological examination confirms the diagnosis. The female patient in this case report presented with chest pain, palpitation of three weeks duration and was found on evaluation to have an abdominal mass concerning for pheochromocytoma. She was treated with surgical resection. The pheo measured 20.5 x 18 x 10 cm and weighed 2,582 grams. Pathological examination confirmed the diagnosis of pheochromocytoma.

Large Unilateral Adrenal Mass with Surrounding Brown Fat: A Case Report

Pheochromocytomas are rare tumors derived from chromaffin cells located in the adrenal and extra adrenal tissues. Pheochromocytomas are diagnosed biochemically and localized using different imaging modalities. The definitive management is surgical resection. Brown adipose tissues are normally present during fetal development, with regression over time. Brown adipose tissues are thermogenic and usually located in the neck, mediastinum, and retroperitoneum. Here, we report a case of a unilateral pheochromocytoma surrounded by brown fat. The abnormal stimulation of brown fat noted on positive emission tomography scan (PET) resolved after the pheochromocytoma was resected.

Pheochromocytoma Crisis in the ICU: A French Multicenter Cohort Study With Emphasis on Rescue Extracorporeal Membrane Oxygenation

OBJECTIVES

To describe the characteristics, management, and outcome of patients admitted to ICUs for pheochromocytoma crisis.

DESIGN

A 16-year multicenter retrospective study.

SETTING

Fifteen university and nonuniversity ICUs in France.

PATIENTS

Patients admitted in ICU for pheochromocytoma crisis.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

We included 34 patients with a median age of 46 years (40-54 yr); 65% were males. At admission, the median Sequential Organ Failure Assessment score was 8 (4-12) and median Simplified Acute Physiology Score II 49.5 (27-70). The left ventricular ejection fraction was consistently decreased with a median value of 30% (15-40%). Mechanical ventilation was required in 23 patients, mainly because of congestive heart failure. Vasoactive drugs were used in 23 patients (68%) and renal replacement therapy in eight patients (24%). Extracorporeal membrane oxygenation was used as a rescue therapy in 14 patients (41%). Pheochromocytoma was diagnosed by CT in 33 of 34 patients. When assayed, urinary metanephrine and catecholamine levels were consistently elevated. Five patients underwent urgent surgery, including two during extracorporeal membrane oxygenation. Overall ICU mortality was 24% (8/34), and overall 90-day mortality was 27% (9/34). Crude 90-day mortality was not significantly different between patients managed with versus without extracorporeal membrane oxygenation (22% vs 30%) (p = 0.7) despite higher severity scores at admission in the extracorporeal membrane oxygenation group.

CONCLUSIONS

Mortality is high in pheochromocytoma crisis. Routinely considering this diagnosis and performing abdominal CT in patients with unexplained cardiogenic shock may allow an earlier diagnosis. Extracorporeal membrane oxygenation and adrenalectomy should be considered as a therapeutic in most severe cases.

Retroperitoneal paraganglioma-Is pre operative embolization useful?

INTRODUCTION

Paragangliomas (PG) are rare tumors derived from chromaffin cells that are located outside the adrenal gland and are capable of producing catecholamines. The treatment is based on a surgical resection, and there is controversy regarding the usefulness of previously carrying out an embolization and what is the most adequate surgical approach.

CLINICAL CASE

We will present a 17-year-old woman with a retroperitoneal tumour in contact with the aorta and the inferior vena cava, treated with embolization prior to the surgical resection via laparotomy.

DISCUSSION

The PG tumors are very infrequent and originate in the extra-adrenal chromaffin cells that exist in the vicinity of the components of the autonomic nervous system. Most of them (86%) produce catecholamines, are unique, sporadic, benign and more frequent in middle-aged women. Since they are radioresistant tumors, the only possibility for a cure is by a complete surgical excision. The preoperative embolization has been described mainly as the treatment of cervical PG, although its use in abdominal PG is more controversial and is not done in a systematic manner.

CONCLUSION

We can conclude that the embolization of abdominal PG is not free of risks and that it has not been demonstrated that it significantly reduces the peri-operative bleeding or the surgical time. Probably, the embolization should be reserved for intensively hypervascularized and larger PGs.

Palpitations, headache and night sweats caused by a retroperitoneal mass: case report and short review

A 31-year-old West-African female attended our emergency department presenting with palpitations, headache, fatigue and night sweats during the last 2 weeks. Clinical examination revealed tachycardia and a painful, palpable infraumbilical mass. Ultrasound examination of the abdomen showed a smoothly rounded soft-tissue mass with a diameter of 5 cm. On contrast-enhanced CT, a prevertebral mass with intense contrast enhancement was seen, located caudal to the aortic bifurcation. On PET-CT, there were no distant ¹⁸F-FDG-avid locoregional nodes or masses. A tumourectomy was successfully performed, during which manipulation of the retroperitoneal tumour triggered a sharp rise in blood pressure. Histological analysis confirmed the diagnosis of a paraganglioma. The clinical complaints of headache, paroxysmal palpitations and night sweats disappeared postoperatively. This case is a classic presentation of a paraganglioma occurring in the organs of Zuckerkandl, a collection of paraganglia. The diagnosis should be suspected in the presence of a heterogeneous, hypervascular mass in the retroperitoneum and typical clinical symptoms of hypertension, headache and palpitations. Treatment involves surgical resection, after accurate preoperative management. Genetic counselling is required, allowing a personal and genotype-based follow-up.

Medullary Thyroid Carcinoma in MEN2A: ATA Moderate- or High-Risk RET Mutations Do Not Predict Disease Aggressiveness

CONTEXT

High-risk RET mutations (codon 634) are associated with earlier development of medullary thyroid carcinoma (MTC) and presumed increased aggressiveness compared with moderate-risk RET mutations.

OBJECTIVE

To determine whether high-risk RET mutations are more aggressive.

DESIGN

Retrospective cohort study using institutional multiple endocrine neoplasia type 2 registry.

SETTING

Tertiary cancer care center.

PATIENTS

Patients with MTC and moderate- or high-risk germline RET mutation.

INTERVENTION

None (observational study).

MAIN OUTCOME MEASURES

Proxies for aggressiveness were overall survival (OS) and time to distant metastatic disease (DMD).

RESULTS

A total of 127 moderate-risk and 135 high-risk patients were included (n = 262). Median age at diagnosis was 42.3 years (range, 6.4 to 86.4 years; mean, 41.6 years) for moderate-risk mutations and 23.0 years (range, 3.7 to 66.8 years; mean, 25.6 years) for high-risk mutations (P < 0.0001). Moderate-risk patients had more T3/T4 tumors at diagnosis (P = 0.03), but there was no significant difference for N or M stage and no significant difference in OS (P = 0.40). From multivariable analysis for OS, increasing age [hazard ratio (HR), 1.05/y; 95% confidence interval (CI), 1.03 to 1.08], T3/T4 tumor (HR, 2.73; 95% CI, 1.22 to 6.11), and M1 status at diagnosis (HR, 3.93; 95% CI, 1.61 to 9.59) were significantly associated with worse OS but high-risk mutation was not (P = 0.40). No significant difference was observed for development of DMD (P = 0.33). From multivariable analysis for DMD, only N1 status at diagnosis was significant (HR, 2.10; 95% CI, 1.03 to 4.27).

CONCLUSIONS

Patients with high- and moderate-risk RET mutations had similar OS and development of DMD after MTC diagnosis and therefore similarly aggressive clinical courses. High-risk connotes increased disease aggressiveness; thus, future guidelines should consider RET mutation classification by disease onset (early vs late) rather than by risk (high vs moderate).

Endometrial cancer gene panels: clinical diagnostic vs research germline DNA testing

Endometrial cancer is the most common gynecological cancer, but is nevertheless uncommon enough to have value as a signature cancer for some hereditary cancer syndromes. Commercial multigene testing panels include up to 13 different genes annotated for germline DNA testing of patients with endometrial cancer. Many other genes have been reported as relevant to familial endometrial cancer from directed genome-wide sequencing studies or multigene panel testing, or research. This review assesses the evidence supporting association with endometrial cancer risk for 32 genes implicated in hereditary endometrial cancer, and presents a summary of rare germline variants in these 32 genes detected by analysis of quasi-population-based endometrial cancer patients from The Cancer Genome Atlas project. This comprehensive investigation has led to the conclusion that convincing evidence currently exists to support clinical testing of only six of these genes for diagnosis of hereditary endometrial cancer. Testing of endometrial cancer patients for the remaining genes should be considered in the context of research studies, as a means to better establish the level of endometrial cancer risk, if any, associated with genetic variants that are deleterious to gene or protein function. It is acknowledged that clinical testing of endometrial cancer patients for several genes included on commercial panels may provide actionable findings in relation to risk of other cancers, but these should be considered secondary or incidental findings and not conclusive evidence for diagnosis of inherited endometrial cancer. In summary, this review and analysis provides a comprehensive report of current evidence to guide the selection of genes for clinical and research gene testing of germline DNA from endometrial cancer patients.

Pheochromocytoma, diagnosis and treatment: Review of the literature

OBJECTIVE

We conducted an extensive review of the literature and tried to cite the most recent recommendations concerning the pheochromocytoma (PHEO).

METHODS

Pub Med and Google Scholar databases were searched systematically for studies concerning pheochromocytomas (intra-adrenal paragangliomas) from 1980 until 2016. Bibliographies were searched to find additional articles.

RESULTS

More than four times elevation of plasma fractionated metanephrines or elevated 24-h urinary fractionated metanephrines are keys to diagnosing pheochromocytoma. If the results are equivocal then we perform the clonidine test. If we have not done it already, we preferably do a CT scan and/or an MRI scan. The patient needs pre-treatment with α1-blockers at least 10-14 days before operation. Alternatives or sometimes adjuncts are Calcium Channels Blockers and/or β-Blockers. Several familial syndromes are associated with PHEO and genetic testing should be considered.

CONCLUSIONS

The biggest problem for pheochromocytoma is to suspect it in the first place. Elevated metanephrines establish the diagnosis. With the proper preoperative preparation the risks during operation and the postoperative period are minimal. If there is a risk of the hereditable mutation, it is strongly suggested that all the patients with pheochromocytoma need clinical genetic testing.

Metastatic Malignant Paraganglioma: A Case Report and Review of Literature

Metastasis is a rare presentation of non-secretory paraganglioma. Consequently, there is no standard of care for the treatment of metastatic malignant paraganglioma. The most widely used chemotherapy regimen for non-resectable cases includes cyclophosphamide, vincristine, and dacarbazine (CVD). CVD has been previously studied with variable therapeutic response. However, yttrium-90 (Y90) radioembolization has not been previously studied in the treatment of hepatic metastasis in patients diagnosed with malignant paraganglioma. This case report follows the treatment of a patient with stage IV mediastinal paraganglioma with metastasis to the liver. Treatment consisted of the CVD chemotherapy regimen and Y90 radioembolization of the hepatic lesions. After 10 cycles of CVD, the tumor size has decreased from 6.0 × 8.8 to 5.5 × 3.0 × 3.4 cm on computed tomography scan. The prominent metastatic liver lesions responded after Y90 radioembolization of both the right and left hepatic arteries. The prominent right hepatic lobe lesion has decreased in size from 2.6 × 3.4 × 3.0 cm to 2.6 × 2.8 × 2.9 cm. The prominent left hepatic lobe lesion originally measuring 1.6 cm in diameter completely resolved on follow-up imaging studies. After completion of 12 cycles of chemotherapy, the most recent positron emission testing scan determined no evidence of disease regarding both the primary mass and the hepatic lesions. This study demonstrates the first case of combination chemotherapy and Y90 radioembolization with a complete response per response evaluation criteria in solid tumors criteria. The approaches toward diagnosis and treatment corresponding to this case of malignant metastatic paraganglioma are also reviewed in this study.

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.

Molecular markers of paragangliomas/pheochromocytomas

Paragangliomas/pheochromocytomas comprise rare tumors that arise from the extra-adrenal paraganglia, with an incidence of about 2 to 8 per million people each year. Approximately 40% of cases are due to genetic mutations in at least one out of more than 30 causative genes. About 25-30% of pheochromocytomas/paragangliomas develop under the conditions of a hereditary tumor syndrome a third of which are caused by mutations in the VHL gene. Together, the gene mutations in this disorder have implicated multiple processes including signaling pathways, translation initiation, hypoxia regulation, protein synthesis, differentiation, survival, proliferation, and cell growth. The present review contemplates the mutations associated with the development of pheochromocytomas/paragangliomas and their potential to serve as specific markers of these tumors and their progression. These data will improve our understanding of the pathogenesis of these tumors and likely reveal certain features that may be useful for early diagnostics, malignancy prognostics, and the determination of new targets for disease therapeutics.

The role of hepatic trans-arterial chemoembolization in metastatic medullary thyroid carcinoma: a specialist center experience and review of the literature

BACKGROUND

Liver metastases are relatively common in patients with metastatic medullary thyroid carcinoma (MTC), carrying a negative impact on disease prognosis. The options for selective therapy of liver metastases in MTC patients are limited to catheter-guided procedures such as trans-arterial chemoembolization (TACE). Data regarding the effectiveness and safety of this procedure in MTC are limited.

AIM

To explore the clinical outcome, survival and safety profile of TACE for liver metastases in a group of MTC patients.

METHODS

Retrospective case series of patients treated at a single tertiary University Medical Center from 2005 to 2015.

RESULTS

Seven consecutive patients (mean age 64.5 ± 10.9 years, 5 females) with histologically confirmed MTC with liver metastases were included. Metastatic involvement of the liver was less than 50% of the liver volume in all patients. The median size of the largest liver lesion was 40 ± 6.9 mm. The patients underwent in total 20 sessions of TACE. Clinical improvement as well as tumor response (PR) were observed in all patients. The median time to tumor progression was 38 months (range 8-126). Three patients were still alive at the end of the follow-up period (a median overall survival rate of 57 ± 44 months).

CONCLUSION

TACE in MTC patients with hepatic metastases is usually well tolerated and induces both clinical improvement and tumor response for prolonged periods of time in the majority of patients. This therapeutic option should always be considered, irrespective of the presence of extrahepatic metastasis.

En Bloc Resection with Major Blood Vessel Reconstruction for Locally Invasive Retroperitoneal Paragangliomas: A 15-Year Experience with Literature Review

BACKGROUND

Retroperitoneal paragangliomas (PGs) are a rare subgroup of neuroendocrine tumors that are commonly located alongside the abdominal aorta. Complete tumor resection is thought to be restricted in patients with major blood vessel involvement. However, no study has specifically focused on aggressive surgical treatment in such patients. We evaluated the value of en bloc resection with major blood vessel reconstruction for locally invasive retroperitoneal PGs.

METHODS

Twenty-nine patients with retroperitoneal PGs with major blood vessel involvement were included in this retrospective study. Survival was compared between patients who underwent en bloc resection with major blood vessel reconstruction and those who underwent medical treatment. Prognostic predictors were analyzed in patients who underwent en bloc resection with major blood vessel reconstruction.

RESULTS

All 11 patients who underwent medical treatment obtained a pathological diagnosis by computed tomography-guided percutaneous needle biopsy. All 18 patients who underwent en bloc resection with major blood vessel reconstruction achieved complete tumor resection. Overall survival was higher in patients who underwent complete tumor resection than in those who underwent medical treatment (p < 0.05). No perioperative mortality occurred in patients who underwent complete tumor resection. Patients with no metastasis, no organ invasion, R0 resection, a Ki-67 index of ≤3%, and a tumor diameter of ≤11.7 cm showed better tumor-free survival (p < 0.05).

CONCLUSIONS

En bloc resection with major blood vessel reconstruction can be successfully performed and provide satisfactory outcomes for patients with locally invasive retroperitoneal PGs. This technique may become a standard surgical strategy for properly selected patients.

Extra-adrenal pheochromocytoma at the organ of Zuckerkandl: a case report and literature review

Pheochromocytomas and paragangliomas are tumors that occur in characteristic locations and are commonly detected on imaging studies. A correct diagnosis is important because of differences in associated neoplasms, risk for malignancy, and need for genetic testing. In addition, associated complications, including death, can be avoided if appropriately recognized and treated. Here, we report a rare case of an extra-adrenal paraganglioma of the organ of Zuckerkandl.

Genitourinary paraganglioma: Demographic, pathologic, and clinical characteristics in the surveillance, epidemiology, and end results database (2000-2012)

BACKGROUND

Extra-adrenal paragangliomas (PGLs) are infrequent, benign, and neuroendocrine tumors arising from chromaffin cells of the autonomic nervous system. Most PGLs are sporadic, but up to 32% are associated with inherited syndromes such as neurofibromatosis type 1, von Hippel-Lindau disease, and familial PGL. Although most PGLs develop above the umbilicus, they have been reported in the genitourinary (GU) tract. Owing to the paucity of literature on the rates of GU PGL, the objective of our study is to describe the demographic, pathologic, and clinical characteristics of GU PGL, and compare them to non-GU sites of PGL using the surveillance, epidemiology, and end results (SEER) database.

METHODS

The SEER 18 database was used to identify all cases of PGL from 2000 to 2012. Demographic, pathologic, and clinical characteristics were described using chi-square and t-test for categorical and continuous variables, respectively. The Kaplan-Meier method was used to compare overall survival (OS) between GU and non-GU PGL. Statistical significance was defined as P<0.05. All analyses were performed using excel and SAS/Stat version 9.4.

RESULTS

A total of 299 cases of PGL were retrieved from SEER, and 20 (6.7%) of the total PGL arose from the GU tract. The mean age at diagnosis was higher in non-GU than GU PGL (50.4±17.2 vs. 40.8±15.6, P = 0.026). Furthermore, 75% of GU PGLs developed in the bladder, followed by the kidneys/renal pelvis, and spermatic cord (20%). Non-GU PGL developed most frequently within the endocrine system (43%). PGL, overall, was more common in men than in women, and it was more common in whites than all other races. Although 55.5% of GU PGLs were organ confined, only 22.2% of non-GU PGLs were localized at diagnosis. All cases of PGL were treated with surgery. There were 2 cause-specific deaths in the GU PGL groups between 2000 and 2012. The 5-year OS was 93.3% for GU PGL vs. 65.5% in non-GU PGL (P = 0.062).

CONCLUSIONS

GU PGL remains rare with low incidence (6.7% of all PGL cases) in the US population between 2000 and 2012. Bladder PGL represents just 5% of all PGL. Moreover, GU PGL had better OS compared to PGL developing outside of the GU tract although the P-value only approached statistical significance. The bladder represents the most common site of involvement, and surgery is the mainstay of treatment for GU PGL. Clearer prognostic factors, including tumor grade and stage, are needed to better elucidate PGL management in the future; thus, pooled studies from various institutions with detailed clinical information are needed to delineate these prognostic factors.

Perioperative Management of Pheochromocytoma

Pheochromocytomas are rare neuroendocrine tumors that produce and store catecholamines. Without adequate preparation, the release of excessive amounts of catecholamines, especially during anesthetic induction or during surgical removal, can produce life-threatening cardiovascular complications. This review focuses on the perioperative management of pheochromocytoma/paragangliomas, initially summarizing the clinical aspects of the disease and then highlighting the current evidence available for preoperative, intraoperative, and postoperative anesthetic management.

The clinical utility of circulating neuroendocrine gene transcript analysis in well-differentiated paragangliomas and pheochromocytomas

CONTEXT

Paragangliomas and pheochromocytomas (PPGLs) exhibit variable malignancy, which is difficult to determine by histopathology, amine measurements or tissue genetic analyses.

OBJECTIVE

To evaluate whether a 51-neuroendocrine gene blood analysis has clinical utility as a diagnostic and prognostic marker.

DESIGN

Prospective cohort study. Well-differentiated PPGLs (n = 32), metastatic (n = 4); SDHx mutation (n = 25); 12 biochemically active, Lanreotide treated (n = 4). Nine patients had multiple sampling. Age- and gender-matched controls and GEP-NETs (comparators).

METHODS

Circulating neuroendocrine tumor mRNA measured (qPCR) with multianalyte algorithmic analysis. Metabolic, epigenomic and proliferative genes as well as somatostatin receptor expression were assessed (averaged, normalized gene expression: mean ± s.e.m.). Amines were measured by HPLC and chromogranin A by ELISA. Analyses (2-tailed): Fisher's test, non-parametric (Mann-Whitney), receiver-operator curve (ROC) and multivariate analysis (MVA). All data are presented as mean ± s.e.m.

RESULTS

PPGL were NETest positive (100%). All exhibited higher scores than controls (55 ± 5% vs 8 ± 1%, P = 0.0001), similar to GEP-NETs (47 ± 5%). ROC analysis area under curve was 0.98 for differentiating PPGLs/controls (cut-off for normal: 26.7%). Mutation status was not directly linked to NETest. Genetic and molecular clustering was associated (P < 0.04) with NETest scores. Metastatic (80 ± 9%) and multicentric (64 ± 9%) disease had significantly (P < 0.04) higher scores than localized disease (43 ± 7%). Progressive disease (PD) had the highest scores (86 ± 2%) vs stable (SD, 41 ± 2%) (P < 0.0001). The area under the curve for PD from SD was 0.93 (cut-off for PD: 53%). Proliferation, epigenetic and somatostatin receptor gene expression was elevated (P < 0.03) in PD. Metabolic gene expression was decreased in SDHx mutations. Repeat NETest measurements defined clinical status in the 9 patients (6 SD and 3 PD). Amine measurement was non-informative. Multivariate analysis identified NETest >53% as an independent prognostic factor.

CONCLUSION

Circulating NET transcript analysis is positive (100% diagnostic) in well-differentiated PCC/PGL, scores were elevated in progressive disease irrespective of mutation or biochemical activity and elevated levels were prognostic.

Leptomeningeal dissemination of a low-grade lumbar paraganglioma: case report

Leptomeningeal dissemination of paraganglioma is rare, with only 2 prior cases in the literature. The authors present the case of a metastatic low-grade lumbar paraganglioma via leptomeningeal dissemination. This report emphasizes the utility of 3,4-dihydroxy-6-¹⁸F-fluoro-l-phenylalanine (¹⁸F-FDOPA) PET scanning for diagnosis, as well as the combination of radiation therapy and alkylating chemotherapeutic agents for the treatment of this rare phenomenon. The patient was a 61-year-old woman who presented with low-back pain and was found to have an isolated L-3 intrathecal tumor on MRI. Sixteen months after gross-total en bloc resection of the paraganglioma, the patient again became symptomatic with new neurological symptoms. MRI findings revealed enhancing leptomeningeal nodules throughout the spine. ¹⁸F-FDOPA PET/CT scanning was used to confirm the diagnosis of disseminated paraganglioma. Intrathecal thiotepa, radiation therapy, and systemic therapy with capecitabine and temozolomide have been used sequentially over a 2-year period, with each able to stabilize tumor growth for several months. The authors also summarize the 2 other reports of leptomeningeal dissemination of paragangliomas in the literature and compare the course and management of the 3 cases.

From Bad to Worse: Paraganglioma Diagnosis during Induction of Labor for Coexisting Preeclampsia

Pheochromocytomas and extra-adrenal paragangliomas are catecholamine-secreting tumors that rarely occur in pregnancy. The diagnosis of these tumors in pregnancy can be challenging given that many of the signs and symptoms are commonly attributed to preeclampsia or other more common diagnoses. Early diagnosis and appropriate management are essential in optimizing maternal and fetal outcomes. We report a rare case of a catecholamine-secreting tumor in which diagnosis occurring at the time labor was being induced for concomitant preeclampsia with severe features. Her initial presentation in hypertensive crisis with other symptoms led to diagnostic workup for secondary causes of hypertension and led to eventual diagnosis of paraganglioma. Obtaining this diagnosis prior to delivery was essential, as this led to prompt multidisciplinary care, changed the course of her clinical management, and ultimately enabled good maternal and fetal outcomes. This case highlights the importance of maintaining a high index of suspicion for secondary causes of hypertension and in obstetric patients and providing timely multidisciplinary care.

Detection of Molecular Alterations in Medullary Thyroid Carcinoma Using Next-Generation Sequencing: an Institutional Experience

Medullary thyroid carcinoma (MTC) harbors rearranged during transfection (RET) gene and rarely RAS gene mutations. The knowledge of the type of gene mutation in MTC is important to determine the treatment of the patients and the management of their family members. Targeted next-generation sequencing with a panel of 47 genes was performed in a total of 12 cases of sporadic (9/12) and hereditary MTC (3/12). Two of three hereditary MTCs had RET/C634R mutation, while the other one harbored two RET mutations (L790F and S649L). All the sporadic MTC had RET/M918T mutation except one case with HRAS mutation. Next-generation sequencing (NGS) can provide comprehensive analysis of molecular alterations in MTC in a routine clinical setting, which facilitate the management of the patient and the family members.

Rapid-sequence MRI for long-term surveillance for paraganglioma and phaeochromocytoma in patients with succinate dehydrogenase mutations

BACKGROUND

Patients with SDHx mutations need long-term radiological surveillance for the development of paragangliomas and phaeochromocytomas, but no longitudinal data exist. The aim of the study was to assess the performance of rapid-sequence non-contrast magnetic resonance imaging (MRI) in the long-term monitoring of patients with SDHx mutations.

METHODS

Retrospective study between 2005 and 2015 at a University Hospital and regional endocrine genetics referral centre. Clinical and imaging data of 47 patients with SDHx mutations (SDHB (36), SDHC (6) and SDHD (5)) who had surveillance for detection of paragangliomas by rapid-sequence non-contrast MRI (base of skull to pubic symphysis) were collected.

RESULTS

Twelve index cases (nine SDHB, one SDHC and two SDHD) and 35 mutation-positive relatives were monitored for a mean of 6.4 years (range 3.1-10.0 years). Mean age at the end of the study: SDHB 46.9 ± 17.6 years; SDHC 42.3 ± 24.4 years; SDHD 54.9 ± 10.6 years. On excluding imaging at initial diagnosis of index cases, 42 patients underwent 116 rapid-sequence MRI scans: 83 scans were negative and 31 scans were positive for sPGL/HNPGL in 13 patients. Most patients had multiple scans (n = number of patients (number of rapid-sequence MRI scans during screening)): n = 9 (2), n = 20 (3), n = 6 (4), n = 1 (6). Nine patients (three index) were diagnosed with new paragangliomas during surveillance and non-operated tumour size was monitored in nine patients. There were two false-positive scans (1.6%). Scans were repeated every 27 ± 9 months.

CONCLUSIONS

Biannual rapid-sequence non-contrast MRI is effective to monitor patients with SDHx mutations for detection of new tumours and monitoring of known tumours.

Bronchial Paraganglioma with SDHB Deficiency

Though most paragangliomas arise as sporadic tumors, the recent advantages in the genetic screening revealed that about 30 % of paragangliomas are linked to hereditary mutations, such as those involving SDH genes. A 22-year-old woman carrying a left main bronchus tumor underwent surgery in our institution. Her past medical history included a GIST without KIT or PDGFRA mutation. The histological examination revealed a nested proliferation of medium-sized cells expressing neuroendocrine markers (chromogranin A and synaptophysin). The neoplastic cells failed to express SDHB gene product. These findings led us to the final diagnosis of bronchial paraganglioma in the setting of Carney-Stratakis syndrome. Bronchial paragangliomas are exceedingly rare tumors with polymorphous clinical presentation, and usually benign clinical course. Though most paragangliomas are sporadic, some tumors are associated with specific hereditary disease, especially those occurring in young patients or in combination with other neoplasms.

M918V RET mutation causes familial medullary thyroid carcinoma: study of 8 affected kindreds

Germline mutations in codon 918 of exon 16 of the RET gene (M918T) are classically associated with multiple endocrine neoplasia type 2B (MEN 2B) with highly aggressive medullary thyroid cancer (MTC), pheochromocytoma and a unique phenotype. The objectives of this study are to describe the rare M918V RET mutation discovered in 8 MTC kindreds from Brazil lacking the MEN 2B phenotype classically observed in M918T patients and to investigate the presence of a founder effect for this germline mutation. Eight apparently sporadic MTC cases were diagnosed with the germline M918V RET mutation. Subsequently, their relatives underwent clinical and genetic assessment (n = 113), and M918V was found in 42 of them. Until today, 20/50 M918V carriers underwent thyroidectomy and all presented MTC/C-cell hyperplasia; the remainder carriers are on clinical follow-up. None of the M918V carriers presented clinical features of MEN 2B. Their clinical presentation was heterogeneous, and the age at tumor diagnosis ranged from 24 to 59 years. Lymph node metastases were present in 12/20 patients, and presumable distant metastases in 2/20; in contrast, we observed a carrier of up to 87 years of age without evidence of MTC. Ethnographic fieldwork and haplotype analyses suggested that the founder mutation first settled in that area fifteen generations ago and originated from Portugal. Our study is the first to demonstrate the RET M918V mutation co-segregating in 8 familial MTC kindreds with validated evidence of a founder effect. We suggest that M918V MTC should be clinically considered an American Thyroid Association (ATA) moderate-risk category.