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Objectives: Phaeochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumours with malignant potential and a hereditary basis in almost 40% of patients. Germline genetic testing has transformed the management of PPGL enabling stratification of surveillance approaches, earlier diagnosis and predictive testing of at-risk family members. Recent studies have identified somatic mutations in a further subset of patients, indicating that molecular drivers at either a germline or tumour level can be identified in up to 80% of PPGL cases. The aim of this study was to investigate the clinical utility of somatic sequencing in a large cohort of patients with PPGL in the United Kingdom., Design and Patients: Prospectively collected matched germline and tumour samples (development cohort) and retrospectively collected tumour samples (validation cohort) of patients with PPGL were investigated., Measurements: Clinical characteristics of patients were assessed and tumour and germline DNA was analysed using a next-generation sequencing strategy. A screen for variants within 'mutation hotspots' in 68 human cancer genes was performed., Results: Of 141 included patients, 45 (32%) had a germline mutation. In 37 (26%) patients one or more driver somatic variants were identified including 26 likely pathogenic or pathogenic variants and 19 variants of uncertain significance. Pathogenic somatic variants, observed in 25 (18%) patients, were most commonly identified in the VHL, NF1, HRAS and RET genes. Pathogenic somatic variants were almost exclusively identified in patients without a germline mutation (all but one), suggesting that somatic sequencing is likely to be most informative for those patients with negative germline genetic test results., Conclusions: Somatic sequencing may further stratify surveillance approaches for patients without a germline genetic driver and may also inform targeted therapeutic strategies for patients with metastatic disease., (© 2021 The Authors. Clinical Endocrinology published by John Wiley & Sons Ltd.)

Objectives: Pheochromocytomas are rare tumors which can present with heterogeneous secretion profiles, clinical manifestations, and radiologic appearance. Under a histopathological point of view, they can be characterized as more or less aggressive with the Pheochromocytoma of the Adrenal gland Scaled Score (PASS) and the Grading system for Adrenal Pheochromocytoma and Paraganglioma (GAPP) score. The aim of this study is to analyze the texture analysis characteristics of pheochromocytoma and identify whether the texture analysis can yield information aiding in the diagnosis and the characterization of those tumors., Methods: Radiological, biochemical, and histopathological data regarding 30 consecutive patients with histologically confirmed pheochromocytoma were analyzed. Images obtained in the unenhanced, late arterial, venous, and delayed phases were used for the texture analysis., Results: Urinary epinephrine and metanephrine levels showed a significant correlation (R 2  = 0.946; R 2  = 699) in the multivariate linear model with texture features, as well as Ki-67 (R 2  = 0.397), PASS score (R 2  = 0.182), GAPP score (R 2  = 0.705), and cellularity showed a significant correlation (R 2  = 0.389). The cluster analysis based on radiomic features resulted in 2 clusters, with significative differences in terms of systolic and diastolic blood pressure values at the time of diagnosis (p = 0.025), GAPP score (4 vs 6, p = 0.05), histological pattern (1-2, p = 0.039), and comedonecrosis (0% vs 50%, p = 0.013)., Conclusion: In conclusion, our study provides the proof of concept for the use of texture analysis on contrast-enhanced CT images as a noninvasive, quantitative tool for helping in the characterization of the clinical, biochemical, and histopathological features of pheochromocytoma., (© 2022. The Author(s).)

The neuroendocrine tumours paraganglioma and pheochromocytoma (PPGLs) are commonly associated with succinate dehydrogenase (SDH) gene variants, but no human SDH-related PPGL-derived cell line has been developed to date. The aim of this study was to systematically explore practical issues related to the classical 2D-culture of SDH-related human paragangliomas and pheochromocytomas, with the ultimate goal of identifying a viable tumour-derived cell line. PPGL tumour tissue/cells (chromaffin cells) were cultured in a variety of media formulations and supplements. Tumour explants and dissociated primary tumour cells were cultured and stained with a range of antibodies to identify markers suitable for use in human PPGL culture. We cultured 62 PPGLs, including tumours with confirmed SDHB, SDHC and SDHD variants, as well as several metastatic tumours. Testing a wide range of basic cell culture media and supplements, we noted a marked decline in chromaffin cell numbers over a 4-8 week period but the persistence of small numbers of synaptophysin/tyrosine hydroxylase-positive chromaffin cells for up to 99 weeks. In cell culture, immunohistochemical staining for chromogranin A and neuron-specific enolase was generally negative in chromaffin cells, while staining for synaptophysin and tyrosine hydroxylase was generally positive. GFAP showed the most consistent staining of type II sustentacular cells. Of the media tested, low serum or serum-free media best sustained relative chromaffin cell numbers, while lactate enhanced the survival of synaptophysin-positive cells. Synaptophysin-positive PPGL tumour cells persist in culture for long periods but show little evidence of proliferation. Synaptophysin was the most consistent cell marker for chromaffin cells and GFAP the best marker for sustentacular cells in human PPGL cultures., Competing Interests: The authors have declared that no competing interests exist.

Von Hippel-Lindau (VHL) disease is an autosomal dominant disease related to germline mutations in VHL. In VHL disease, pheochromocytoma develops in 10%-20% of patients because of germline mutations and loss of heterozygosity of VHL. However, the rate of paraganglioma associated with VHL is low compared with that of pheochromocytoma, and the reason is unknown. In this study, we performed germline and somatic mutation analyses of retroperitoneal paraganglioma that developed in a patient with clinically diagnosed VHL disease and investigated the tumorigenic mechanism of paraganglioma. The patient was a 25-year-old woman who was considered to have VHL disease on the basis of her family history. She was referred to our clinic to investigate a tumor at the bifurcation of the common iliac artery. The tumor was diagnosed as retroperitoneal paraganglioma by clinical evaluations. A left renal cell carcinoma was also suspected. Polymerase chain reaction direct sequencing analysis and polymorphic microsatellite analysis within the VHL locus suggested that loss of heterozygosity of VHL was associated with paraganglioma and renal cell carcinoma. Multiplex ligation-dependent probe amplification analysis showed a loss of the copy number of VHL exons in paraganglioma. These results suggest that VHL disease contributes to the development of paraganglioma. A literature review showed no reported common missense variants involved in the progression of paraganglioma. The loss of heterozygosity of VHL can be a tumorigenic mechanism of retroperitoneal paraganglioma in VHL disease. However, the low rate of paraganglioma compared with pheochromocytoma is not explained by their genetic background alone.

Context: Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors that are frequently associated with succinate dehydrogenase (SDH) germline mutations. When mutated, SDH losses its function, thus leading to succinate accumulation., Objective: In this study, we evaluated serum succinate levels as a new metabolic biomarker in SDHx-related carriers., Methods: Retrospective monocentric study of 88 PPGL patients (43 sporadic, 35 SDHB, 10 SDHA/C/D), 17 tumor-free familial asymptomatic carriers (13 SDHB, 4 SDHC/D), and 60 healthy controls. Clinical, biological, and imaging data were reviewed. Serum succinate levels (n = 280) were quantified by an ultra-performance liquid chromatography coupled to a tandem mass spectrometry method and correlated to SDHx mutational status, disease extension, and other biological biomarkers., Results: Serum succinate levels > 7 μM allowed identification of tumor-free asymptomatic SDHB-mutated cases compared to a healthy control group (100% specificity; 85% sensitivity). At PPGL diagnosis, SDHB-mutated patients had a significantly increased median succinate level (14 μM) compared to sporadic patients (8 μM) (P < 0.01). Metastatic disease extension was correlated to serum succinate levels (r = 0.81). In the SDHB group, patients displaying highest tumor burdens showed significant increased succinate levels compared to the sporadic group (P < 0.0001)., Conclusions: In this pilot study, we showed that serum succinate level is an oncometabolic biomarker that should be useful to identify SDHB-related carriers. Succinate levels are also a marker of metabolic tumor burden in patients with a metastatic PPGL and a potential marker of treatment response and follow-up., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Emerging evidence suggests the composition of the tumour microenvironment (TME) correlates with clinical outcome and that each tumour type has a unique TME including a variable population of inflammatory cells. We performed immunohistochemistry on 65 phaeochromocytoma and paraganglioma (PPGL) tumour samples with 20 normal adrenal medulla samples for comparison. The immune cells assessed were macrophages, lymphocytes and neutrophils, and we compared the proportion of infiltration of these immune cells with clinical and histopathological factors. There was a higher proportion of immune cells in tumour tissue compared to non-neoplastic adrenal medulla tissue, with a predominance of macrophages. There was a higher proportion of M2:M1 macrophages and T-helper lymphocytes in aggressive tumours compared to indolent ones. For SDHB-associated tumours, there was a higher proportion of M2 macrophage infiltration, with higher M2:M1 in aggressive SDHB PPGLs compared to indolent tumours. These data demonstrate that immune cells do infiltrate the TME of PPGLs, confirming that PPGLs are immunologically active tumours. Differences in the TME of PPGLs were observed between aggressive and indolent tumours. These differences could potentially be exploited as an aid in predicting tumour behaviour.

Pituitary neuroendocrine tumours (PitNETs) associated with paragangliomas or phaeochromocytomas are rare. SDHx variants are estimated to be associated with 0.3-1.8% of PitNETs. Only a few case reports have documented the association with MAX variants. Prolactinomas are the most common PitNETs occurring in patients with SDHx variants, followed by somatotrophinomas, clinically non-functioning tumours and corticotrophinomas. One pituitary carcinoma has been described. SDHC, SDHB and SDHA mutations are inherited in an autosomal dominant fashion and tumorigenesis seems to adhere to Knudson's two-hit hypothesis. SDHD and SDHAF2 mutations most commonly have paternal inheritance. Immunohistochemistry for SDHB or MAX and loss of heterozygosity analysis can support the assessment of pathogenicity of the variants. Metabolomics is promising in the diagnosis of SDHx-related disease. Future research should aim to further clarify the role of SDHx and MAX variants or other genes in the molecular pathogenesis of PitNETs, including pseudohypoxic and kinase signalling pathways along with elucidating epigenetic mechanisms to predict tumour behaviour.

Abstract: A 37-year-old man has palpable bilateral carotid body paragangliomas, larger on the right. The right-sided tumor is avid on both 123 I-MIBG and 68 Ga-DOTATATE PET/CT images. The left-sided tumor is only avid on 68 Ga-DOTATATE PET/CT, but not 123 I-MIBG scan. This case illustrates the heterogeneous features of carotid body paragangliomas., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Surgical resection of pheochromocytoma and paraganglioma (PPGL) may be associated with excessive hemodynamic variability. Whether hemodynamic variability occurs in patients with undiagnosed PPGL undergoing unrelated, non-neuroendocrine, operations is unknown., Methods: We identified patients who underwent non-neuroendocrine surgical procedures up to 5 y before pathologic diagnosis of PPGL. For each PPGL, two non-PPGL patients were matched based on sex, age, type, and year of operation. Electronic medical records were reviewed for intraoperative blood pressures, heart rates, and hemodynamic variability was assessed with range (maximum-minimum), standard deviation, coefficient of variation, and average real variability., Results: Thirty-seven PPGL patients underwent operations preceding the diagnosis of PPGL: 25 pheochromocytomas, 11 paragangliomas, and one metastatic pheochromocytoma. Median interquartile range tumor size at diagnosis was 35 mm (23 to 60). The time from index operation to PPGL diagnosis was ≤12 mo in 21 (56.8%) patients. In 23 (62.2%) patients, the subsequently diagnosed PPGL was functional. Fifteen (40.5%) PPGL and 20 (27.0%) control patients were preoperatively treated for hypertension (P = 0.149). Maximum intraoperative systolic BP was >180 mmHg for 4 (10.8%) PPGL patients and 3 (4.1%) controls (P = 0.219). Two PPGL patients had intraoperative systolic BP >230 mmHg. No significant differences were found with all other measures of intraoperative hemodynamic variability. Similarly, in secondary analysis there was no significant difference in intraoperative hemodynamic variability between biochemically active PPGL and their respective controls., Conclusions: Patients with undiagnosed PPGL undergoing a wide variety of non-neuroendocrine operations had intraoperative hemodynamic variability comparable to non-PPGL patients undergoing the same type of procedures., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Context: Pheochromocytoma and paraganglioma (PPGL) may appear as a complication of cyanotic congenital heart disease (CCHD-PPGL) with frequent EPAS1 mutations, suggesting a close link between EPAS1 mutations and tissue hypoxia in CCHD-PPGL pathogenesis., Objective: Our aim is to further investigate the role of EPAS1 mutations in the hypoxia-driven mechanism of CCHD-PPGL pathogenesis, particularly focusing on metachronous and/or multifocal CCHD-PPGL tumors., Methods: We performed whole-exome sequencing (WES) for somatic and germline mutations in 15 PPGL samples from 7 CCHD patients, including 3 patients with metachronous and/or multifocal tumors, together with an adrenal medullary hyperplasia (AMH) sample., Results: We detected EPAS1 mutations in 15 out of 16 PPGL/AMH samples from 7 cases. Conspicuously, all EPAS1 mutations in each of 3 cases with multifocal or metachronous tumors were mutually independent and typical examples of parallel evolution, which is suggestive of strong positive selection of EPAS1-mutated clones. Compared to 165 The Cancer Genome Atlas non-CCHD-PPGL samples, CCHD-PPGL/AMH samples were enriched for 11p deletions (13/16) and 2p amplifications (4/16). Of particular note, the multiple metachronous PPGL tumors with additional copy number abnormalities developed 18 to 23 years after the resolution of hypoxemia, suggesting that CCHD-induced hypoxic environments are critical for positive selection of EPAS1 mutants in early life, but may no longer be required for development of PPGL in later life., Conclusion: Our results highlight a key role of activated hypoxia-inducible factor 2α due to mutated EPAS1 in positive selection under hypoxic environments, although hypoxemia itself may not necessarily be required for the EPAS1-mutated clones to progress to PPGL., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Context: Sampling of blood in the supine position for diagnosis of pheochromocytoma and paraganglioma (PPGL) results in lower rates of false positives for plasma normetanephrine than seated sampling. It is unclear how inpatient vs outpatient testing and other preanalytical factors impact false positives., Objective: We aimed to identify preanalytical precautions to minimize false-positive results for plasma metanephrines., Methods: Impacts of different blood sampling conditions on plasma metanephrines were evaluated, including outpatient vs inpatient testing, sampling of blood in semi- vs fully recumbent positions, use of cannulae vs direct venipuncture, and differences in outside temperature. A total of 3147 patients at 10 tertiary referral centers were tested for PPGL, including 278 with and 2869 without tumors. Rates of false-positive results were analyzed., Results: Outpatient rather than inpatient sampling resulted in 44% higher plasma concentrations and a 3.4-fold increase in false-positive results for normetanephrine. Low temperature, a semi-recumbent position, and direct venipuncture also resulted in significantly higher plasma concentrations and rates of false-positive results for plasma normetanephrine than alternative sampling conditions, although with less impact than outpatient sampling. Higher concentrations and rates of false-positive results for plasma normetanephrine with low compared with warm temperatures were only apparent for outpatient sampling. Preanalytical factors were without impact on plasma metanephrines in patients with PPGL., Conclusion: Although inpatient blood sampling is largely impractical for screening patients with suspected PPGL, other preanalytical precautions (eg, cannulae, warm testing conditions) may be useful. Inpatient sampling may be reserved for follow-up of patients with difficult to distinguish true- from false-positive results., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors in childhood. Up to 40% of PPGL are currently thought to be associated with a hereditary predisposition. Nuclear medicine imaging modalities such as fluorodeoxyglucose positron emission tomography ( 18 F-FDG PET), 68 Ga-DOTATATE PET, and 123 I-metaiodobenzylguanidine ( 123 I-MIBG) scintigraphy play an essential role in the staging, response assessment, and determination of suitability for targeted radiotherapy in patients with PPGL. Each of these functional imaging modalities targets a different cellular characteristic and as such can be complementary to anatomic imaging and to each other. With the recent US Food and Drug Administration approval and increasing use of 68 Ga-DOTATATE for imaging in children, the purpose of this article is to use a case-based approach to highlight both the advantages and limitations of DOTATATE imaging as it is compared to current radiologic imaging techniques in the staging and response assessment of pediatric PPGL, as well as other neuroendocrine malignancies., (© 2022 Wiley Periodicals LLC.)

Background: SDHB is one of the major genes predisposing to paraganglioma/pheochromocytoma (PPGL). Identifying pathogenic SDHB variants in patients with PPGL is essential to the management of patients and relatives due to the increased risk of recurrences, metastases and the emergence of non-PPGL tumours. In this context, the 'NGS and PPGL (NGSnPPGL) Study Group' initiated an international effort to collect, annotate and classify SDHB variants and to provide an accurate, expert-curated and freely available SDHB variant database., Methods: A total of 223 distinct SDHB variants from 737 patients were collected worldwide. Using multiple criteria, each variant was first classified according to a 5-tier grouping based on American College of Medical Genetics and NGSnPPGL standardised recommendations and was then manually reviewed by a panel of experts in the field., Results: This multistep process resulted in 23 benign/likely benign, 149 pathogenic/likely pathogenic variants and 51 variants of unknown significance (VUS). Expert curation reduced by half the number of variants initially classified as VUS. Variant classifications are publicly accessible via the Leiden Open Variation Database system (https://databases.lovd.nl/shared/genes/SDHB)., Conclusion: This international initiative by a panel of experts allowed us to establish a consensus classification for 223 SDHB variants that should be used as a routine tool by geneticists in charge of PPGL laboratory diagnosis. This accurate classification of SDHB genetic variants will help to clarify the diagnosis of hereditary PPGL and to improve the clinical care of patients and relatives with PPGL., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ.)

Purpose: Pheochromocytoma/paraganglioma (PCC/PGL; collectively known as PPGL) can be driven by germline and somatic mutations in susceptibility genes. We aimed to investigate the mutation profile and clinical features of pathogenic genes in highly genetically heterogeneous PPGL and to preliminary explore molecular therapeutic targets in PPGL., Methods: We established a panel of 260 genes, including susceptibility genes of PPGL and other important tumorigenic genes to sequence 107 PPGL tissues., Results: Overall, 608 genomic mutations were identified in 107 PPGL tissues. Almost 57% of PPGL tissue samples exhibited pathogenic mutations, and the most frequently mutated gene was SDHB (15/107, 14%). SDHB and HRAS were the most commonly mutated genes in germline-mutated PPGL (25/107, 23%) and nongermline-mutated PPGL (36/107, 34%), respectively. In addition, novel pathogenic mutations were detected in sporadic PPGL. PPGL with mutations in the hypoxia pathway had an earlier onset and higher norepinephrine level than those in the kinase pathway. Receptor tyrosine kinase (RTK; 22%, 24/107), mitogen-activated protein kinase (MAPK; 14%, 15/107), and tyrosine kinase (TK; 2%, 2/107) pathways were the most frequently mutated pathways in PPGL., Conclusion: Our results provided the genetic mutation profile in PPGL tissues. Genetic mutations in PPGL were mainly concentrated in the RTK, TK, and MAPK pathways, suggesting potential molecular therapeutic targets for PPGL., Competing Interests: Authors MZ and CZ were employed by the company Novogene Bioinformatics Technology Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ma, Ling, Zhao, Wang, Cui, Wen, Ji, Zhang, Chen, Tong and Li.)

Malignant pheochromocytomas (PHEOs)/paragangliomas (PGLs) are rare tumors for which clinical outcomes remain poorly defined and therapeutic options are limited. Approximately 27% carry pathogenic germline succinate dehydrogenase (SDHx) mutations; the presence of such mutations has been correlated with response to temozolomide (TMZ). We aimed to investigate the association between germline mutations in SDHx and response to TMZ. We retrospectively identified patients with metastatic malignant PHEO/PGLs treated with TMZ- based chemotherapy at Dana-Farber Cancer Institute between 2003 and 2020. The correlation between response by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and PET Response Criteria in Solid Tumors (PERCIST) and the presence of SDHx mutations in the germline and tumor was evaluated. Nineteen patients received TMZ. Seventeen underwent germline assessment: 9 (53%) carried a pathogenic SDHx germline mutation. Fifteen patients were evaluable for response by RECIST 1.1: 6 (40%) partial response, 4 (27%) stable disease, and 5 (33%) progressive disease. Overall median progression-free survival was 2.2 years. Three-year overall survival (OS) was 58%. Median PFS was 1.3 years and 5.5 years for carriers and non-carriers, respectively and OS was 1.5 years and not estimable for carriers and non-carriers, respectively. The response by PERCIST criteria in nine patients correlated with the RECIST 1.1 assessment. Our series represents one of the largest analyses of patients with malignant PHEOs/PGLs treated with TMZ who have available germline data. The incidence of pathogenic germline SDHx mutations was similar to what has been previously published, though our analysis suggests that there may be a limited association between response to TMZ and pathogenic germline SDHx mutations.

Objective: To explore the clinical characteristics and diagnosis and treatment in the patients presenting with granulation tissue of the external auditory canal. Methods: The data of 71 postoperative patients presenting with granulation tissue of the external auditory canal in the Department of Otolaryngology, the First Affiliated Hospital of the Air Force Military Medical University from January 2015 to June 2020 were analyzed retrospectively, including the chief complaint, physical examination, auxiliary examination and preoperative imaging, biopsy was performed when necessary to confirm the diagnosis. Among the 71 patients, 30 cases were diagnosed as chronic otitis media, 19 cases were external auditory canal cholesteatoma, 5 cases were external auditory canal carcinoma, 6 cases were paraganglioma, 1 case was granulomatous hemangioma, 1 case was first branchial cleft fistula, 4 cases were granuloma of the external auditory canal, 4 cases were hemangioma of the external auditory canal, and 1 case was foreign body of the external auditory canal. Individualized treatment plans are made according to the characteristics and extent of the lesions. Results: Postoperative follow-up was 12 to 74 months, with an average of （44±18.1） months. Seventy patients（98.6%） had no complications such as sensorineural deafness, external auditory stenosis or peripheral facial paralysis after surgery, and one patient with paraganglioma had postoperative neurological function grade Ⅱ, and was treated with nutritional nerves, and the postoperative neural function recovered to grade Ⅰ after 3 months. Conclusion: The patients presenting with granulation tissue of the external auditory canal can be diagnosed as various diseases. It is necessary to analyze the patient's medical history in detail, confirm the diagnosis in combination with imaging examination, and formulate an individualized treatment plan to reduce misdiagnosis and missed diagnosis., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Background: Pheochromocytomas and paragangliomas (PPGLs) have a heterogeneous prognosis, the basis of which remains unclear. We, therefore, assessed disease-specific survival (DSS) and potential predictors of progressive disease in patients with PPGLs and head/neck paragangliomas (HNPGLs) according to the presence or absence of metastases., Methods: This retrospective study included 582 patients with PPGLs and 57 with HNPGLs. DSS was assessed according to age, location and size of tumours, recurrent/metastatic disease, genetics, plasma metanephrines and methoxytyramine., Results: Among all patients with PPGLs, multivariable analysis indicated that apart from older age (HR = 5.4, CI = 2.93-10.29, P < 0.0001) and presence of metastases (HR = 4.8, CI = 2.41-9.94, P < 0.0001), shorter DSS was also associated with extra-adrenal tumour location (HR = 2.6, CI = 1.32-5.23, P = 0.0007) and higher plasma methoxytyramine (HR = 1.8, CI = 1.11-2.85, P = 0.0170) and normetanephrine (HR = 1.8, CI = 1.12-2.91, P = 0.0160). Among patients with HNPGLs, those with metastases presented with longer DSS compared to patients with metastatic PPGLs (33.4 versus 20.2 years, P < 0.0001) and only plasma methoxytyramine (HR = 13, CI = 1.35-148, P = 0.0380) was an independent predictor of DSS. For patients with metastatic PPGLs, multivariable analysis revealed that apart from older age (HR = 6.2, CI = 3.20-12.20, P < 0.0001), shorter DSS was associated with the presence of synchronous metastases (HR = 4.9, CI = 2.78-8.80, P < 0.0001), higher plasma methoxytyramine (HR = 2.4, CI = 1.44-4.14, P = 0.0010) and extensive metastatic burden (HR = 2.1, CI = 1.07-3.79, P = 0.0290)., Conclusions: DSS among patients with PPGLs/HNPGLs relates to several presentations of the disease that may provide prognostic markers. In particular, the independent associations of higher methoxytyramine with shorter DSS in patients with HNPGLs and metastatic PPGLs suggest the utility of this biomarker to guide individualized management and follow-up strategies in affected patients., Competing Interests: Conflict of Interest statement The authors declare that they have no financial relationships that could be broadly relevant to the work., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background and Objectives: Paragangliomas are rare neuroendocrine tumors that may localize to the spine causing progressive low back pain variably accompanied by radiculopathy. Recurrence, follow-up duration, and role of adjuvant therapy remain unestablished., Methods: We interrogated our institution's histopathology database for all confirmed cases of spinal paraganglioma between 2000 and 2021. Patient records were retrospectively reviewed to extract diagnostic features, operative treatment, and follow-up outcomes., Results: 6 cases of spinal paraganglioma were surgically treated (67% female vs. 33% male, mean age = 51.3 years). Preoperative symptom duration did not correlate with tumor size (Spearman r = 0.154, P = 0.80). The mean postoperative follow-up duration lasted 3.3 years (range = 2-96 months). There were an equal number of primary and metastatic lesions. 1 tumor exhibited secretory features and was consequently embolized preoperatively. No residual or recurrent disease was evident in the primary cases; however, 2 metastatic cases recurred within 2 years of surgery and 1 patient died., Conclusions: Given nonspecific clinical and radiologic features, spinal paragangliomas are diagnosed via biopsy or after surgery. Complete surgical resection is often necessary to alleviate symptoms and prevent tumor recurrence. In cases with benign metastases, long-term surveillance is important and adjuvant medical and radiotherapeutic treatment may be beneficial., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: Cardiac paraganglioma is a rare tumor that most surgeons have limited experience treating. The objective of this study is to examine the management and outcomes for cardiac paraganglioma treatment when cared for by a multidisciplinary cardiac tumor team., Methods: We reviewed our institutionally approved cardiac tumor database from March 2004 to June 2020 for cardiac paraganglioma. These prospectively collected data were retrospectively reviewed. Patient characteristics were presented for individual patients and as summary statistics. Demographic and clinical data were also reported as median and interquartile range for continuous variables and frequencies and proportions for categoric variables. Kaplan-Meier curves were used to depict the patient survival from surgery., Results: There were 21 cases of primary cardiac paraganglioma, 19 of whom had surgical resection with 3 refusing offered surgery. Of 19 resected tumors, 13 originated from the left atrium and 6 originated from the roots of the pulmonary artery and the aorta. Complex procedures were required, including aortic and pulmonary root replacement and 8 autotransplants. All tumors had complete gross resection with no identifiable disease left behind, but 4 of these had microscopically positive margins. None of the patients had local recurrence of disease. There was 1 case of metastatic paraganglioma with death at 4 years postsurgery. Operative mortality was 10.6%. Survival from surgery was 88.2%, 71.8%, and 71.8% and 1, 5, and 10 years, respectively., Conclusions: Cardiac paraganglioma presents a surgical challenge. Mortality and long-term survival after surgical resection are acceptable but may require complex resection and reconstruction., (Copyright © 2020 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

A 3-year-old male Bichon Frise developed lethargy, anorexia and haematuria. B-scan ultrasonography examination revealed a small, irregular, soft-textured mass in the bladder. Histopathologically, there was an incomplete fibrous pseudocapsule around the tumour tissue and although there was clear demarcation from the surrounding tissue, there was invasion of the capsule. Tumour cells proliferated in nests or cords of variable size, separated by fibrovascular tissue. The neoplastic cells were immunopositive for chromogranin A, synaptophysin and neuron-specific enolase, and electron microscopy revealed that they contained cytoplasmic secretory granules. On the basis of these findings, the tumour was diagnosed as a primary paraganglioma of the urinary bladder., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In children and adolescents, neuroblastoma (NBL), pheochromocytoma (PCC), and adrenocortical tumors (ACT) can arise from the adrenal gland. It may be difficult to distinguish between these three entities including associated extra-adrenal tumors (paraganglioma, PGL). Precise discrimination, however, is of crucial importance for management. Biopsy in ACT or PCC is potentially harmful and should be avoided whenever possible. We herein report data on 10 children and adolescents with ACT and five with PCC/PGL, previously mistaken as NBL. Two patients with adrenocortical carcinoma died due to disease progression. Two (2/9, missing data in one patient) patients with a final diagnosis of ACT clearly presented with obvious clinical signs and symptoms of steroid hormone excess, while seven patients did not. Blood analyses indicated increased levels of steroid hormones in one additional patient; however, urinary steroid metabolome analysis was not performed in any patient. Two (2/10) patients underwent tumor biopsy, and in two others tumor rupture occurred intraoperatively. In 6/10 patients, ACT diagnosis was only established by a reference pediatric pathology laboratory. Four (4/5) patients with a final diagnosis of PCC/PGL presented with clinical signs and symptoms of catecholamine excess. Urine tests indicated possible catecholamine excess in two patients, while no testing was carried out in three patients. Measurements of plasma metanephrines were not performed in any patient. None of the five patients with PCC/PGL received adrenergic blockers before surgery. In four patients, PCC/PGL diagnosis was established by a local pathologist, and in one patient diagnosis was revised to PGL by a pediatric reference pathologist. Genetic testing, performed in three out of five patients with PCC/PGL, indicated pathogenic variants of PCC/PGL susceptibility genes. The differential diagnosis of adrenal neoplasias and associated extra-adrenal tumors in children and adolescents may be challenging, necessitating interdisciplinary and multidisciplinary efforts. In ambiguous and/or hormonally inactive cases through comprehensive biochemical testing, microscopical complete tumor resection by an experienced surgeon is vital to preventing poor outcome in children and adolescents with ACT and/or PCC/PGL. Finally, specimens need to be assessed by an experienced pediatric pathologist to establish diagnosis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kuhlen, Pamporaki, Kunstreich, Wudy, Hartmann, Peitzsch, Vokuhl, Seitz, Kreissl, Simon, Hero, Frühwald, Vorwerk and Redlich.)

Background: Paraganglioma of the urinary bladder (Pub) is rare and presents with clinical symptoms caused by catecholamine production and release. The typical symptoms of Pub are hypertension, macroscopic hematuria, and a hypertensive crisis during micturition. The average size of detected Pubs is approximately 3 cm. Herein, we report a case of a large Pub in which the symptoms were masked by oral medication, precise preoperative diagnosis was difficult, and intraoperative confirmation of tumoral adhesion to the rectum resulted in hypertensive attacks during surgery., Case Presentation: A 64-year-old Japanese male with a history of hypertension and arrhythmia controlled with oral medication presented with a large tumor in the pelvic region, detected on examination for weight loss, with no clinical symptoms. Computed tomography and magnetic resonance imaging revealed a tumor measuring 77 mm in diameter in the posterior wall of the urinary bladder. The border with the rectum was unclear, and the tumor showed heterogeneous enhancement in the solid part with an enhancing hypodense lesion. Cystoscopy revealed compression of the bladder trigone by external masses; however, no tumor was visible in the lumen. Endoscopic ultrasonography-guided fine-needle aspiration revealed CD34-positive spindle-shaped cells in the fibrous tissue, suggestive of a mesenchymal neoplasm. The tumor was suspected to be a gastrointestinal stromal tumor, and surgery was performed. After laparotomy, we suspected that the tumor had invaded the rectum, and total cystectomy and anterior resection of the rectum were performed. Histologically, the tumor cells had granular or clear amphophilic cytoplasm with an oval nucleus and nests of cells delimited by connective tissue and vascular septations. Immunohistochemically, the tumor was positive for chromogranin A, CD56, and synaptophysin, and a diagnosis of paraganglioma of the urinary bladder was confirmed. There was no tumor recurrence at the 7-month follow-up., Conclusion: This case highlights the importance of careful examination of pelvic tumors, including endocrine testing, for detecting paraganglioma of the urinary bladder in patients with a history of hypertension or arrhythmia., (© 2022. The Author(s).)

Objective: Pheochromocytomas (PHEOs) and paragangliomas (PGLs), collectively known as PPGLs, are tumours with high heritability. The prevalence of germline mutations in apparently sporadic PPGLs varies depending on the study population. The objective of this study was to determine the spectrum of germline mutations in a cohort of patients with apparently sporadic PPGLs over time., Design: We performed a retrospective review of patients with apparently sporadic PPGLs who underwent genetic testing at our referral centre from 2005 to 2020., Patients: We included patients with apparently sporadic PPGLs who underwent genetic testing at our referral center., Measurements: Genetic analysis included sequential gene sequencing by Sanger method or next generation sequencing (NGS) with a multigene panel., Results: The prevalence of germline mutations was 26.2% (43/164); 40.0% (30/75) in PGLs and 14.6% (13/89) in PHEOs. We identified four novel pathogenic variants (two SDHB and two SDHD). Patients carrying germline mutations were younger (38.7 vs. 49.7 years old) than patients with no identified germline mutations. From 2015 to 2020, we performed NGS with a multigene panel on 12 patients for whom the initial genetic analysis was negative. Germline mutations in previously untested genes were found in four (33.3%) of these patients (two MAX and two SDHA), representing 9.3% (4/43) of the mutation carriers., Conclusion: The prevalence of germline mutations in our cohort of patients with apparently sporadic PPGLs was 26.2%. Genetic re-evaluation over time using multigene sequencing by NGS assay in a subgroup of patients leads to an increase in the detection of mutations., (© 2021 John Wiley & Sons Ltd.)

Background: Catecholamine excess arising from pheochromocytomas and paragangliomas (PPGLs) can cause a wide spectrum of cardiac manifestations. Although there are reviews of reported cases, these reviews lack detailed data, which makes it impossible to perform an accurate analysis. In this study, we conducted a comprehensive analysis of cardiovascular complications (CCs), including PPGL-related myocardial injury, cardiogenic shock, and arrhythmias requiring antiarrhythmic therapy, in a large cohort of patients with PPGL., Methods: We retrospectively analyzed the clinical data of consecutive patients with PPGL admitted between January 2018 and June 2020. The prevalence and the characteristics of patients with CCs were investigated. Moreover, comparisons were made between patients with and without CCs., Results: Compared with the non-CC group, the percentage of men was significantly lower (14/41 vs.92/175, 34.1% vs. 52.6%, p = 0.034) and the proportion of patients with paroxysmal hypertension was significantly higher (13/41 vs.29/173, 31.7% vs.16.8%, p = 0.03) in the CC group. More patients showed excessive sweating (19/41 vs 64/175, 46.3% vs. 24.0%, p = 0.004) and PPGL crisis (7/41 vs. 10/175, 17.1% vs.5.7%, p=0.035) in the CC group. In terms of laboratory findings, higher white blood cell [7.36 (6.49, 20.23) vs. 5.95 (5.1, 6.97)×10 9 /L, p<0.001] and platelet [339.28 ± 108.54 vs. 250.66 ± 70.83(×10 9 /L), p = 0.021] counts were more common in the CC group. There was also a higher prevalence of combination-producing PPGL in the CC group (13/24 vs.20/149, 54.2% vs.13.4%, p<0.001). However, the tumor size, invasive behavior on histology, and hemorrhage or necrosis on histology did not differ between the two groups. Platelet count [odds ratio (OR): 1.009; 95% confidence interval (CI) 1.001-1.016; p=0.023] and combination-secreting PPGL (OR: 5.009; 95% CI 1.365-18.38; p=0.015) are independent risk factors for CCs in patients with PPGL., Conclusions: In patients with PPGL, even in the absence of signs and symptoms of CCs, a work up of cardiology should be strongly considered. Importantly, if patients with PPGLs have higher platelet counts and the combination-secreting pattern, they are more likely to have CCs. Thus, a careful cardiac evaluation should be performed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Zhao, Meng, Mei, Fan, Liu, Zhou, Zhu and Zhang.)

Background: Moderately elevated plasma normetanephrine (NMN) levels are frequent among patients with suspected pheochromocytoma and paraganglioma (PPGL). Clonidine suppression testing (CST) is recommended to distinguish patients with from those without PPGL. We aimed at evaluating the diagnostic outcome of CST in patients with moderate NMN elevations., Methods: Data from patients participating in the PMT study (Prospective Monoamine-Producing Tumor) and the ENSAT (European Network for the Study of Adrenal Tumours) registry in 6 European reference centers were analyzed retrospectively. Eighty-nine patients with suspected PPGL and moderate NMN elevations upon screening were included. During follow-up, PPGL was confirmed in 16 and excluded in 73 cases. Plasma NMN was measured by liquid chromatography tandem mass spectrometry before and 180 minutes after oral clonidine. Receiver operating characteristic analysis was performed to identify optimal cutoffs., Results: If published diagnostic criteria for CST (ie, NMN ≥112 ng/L and NMN suppression <40%) were applied, a sensitivity of 88% (CI, 61%-98%) and a specificity of 97% (CI, 90%-100%) were observed. An improved cutoff for plasma NMN 180 minutes after clonidine was established at 80% of the age-related upper limit of normal, resulting in a sensitivity of 94% and a specificity of 97%. False-negative CST results occurred in 2 patients with small PPGL., Conclusions: This study, involving one of the largest cohorts of patients with suspected PPGL and moderately elevated NMN, confirmed the diagnostic accuracy of CST. The application of an adapted cutoff further improved sensitivity.

Abstract: Primary paraganglioma of the trachea is a rare differential among more common tracheal masses. Definitive diagnosis of tracheal masses is obtained via endoscopic biopsy. Utilization of 68Ga-DOTATATE PET/CT is valuable in the workup of these lesions as paragangliomas would have significantly higher radiotracer uptake compared with the more common squamous cell and adenoid cystic carcinomas. This is particularly important in tracheal paragangliomas, which are typically friable and hypervascular with higher risk of significant bleeding on biopsy. In addition, 68Ga-DOTATATE PET/CT can be used to evaluate for local invasion and metastatic disease as a 1-step imaging modality., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Recent progress in paraganglioma (PGL) revealed genotype-phenotype relationship, especially succinate dehydrogenase complex subunit B (SDHB) gene mutation-related to the extra-adrenal origin and metastasis. SDHB-immunohistochemistry can detect all types of SDH-subunit mutations, and is a useful tool to detect SDH-mutation tumors. PGLs usually occur along with sympathetic, and parasympathetic chains, however, colorectal paraganglioma is extremely rare. We have experienced one sigmoid colon PGL and one rectal PGL. These colorectal PGLs: a sigmoid colon PGL measuring 25 mm associated with a gastrointestinal stromal tumor (GIST) of the stomach, and a rectal PGL measuring 75 × 45 mm with elevated norepinephrine level were analyzed by immunohistochemistry for INSM1, chromogranin A, synaptophysin, tyrosine hydroxylase, dopamine-beta-hydroxylase, and SDHB and SDHA. The tumors were strongly positive for above markers, however, negative for SDHB. Both PGLs negative for SDHB immunohistochemistry were defined SDHB-deficient PGLs. Histologic grading of the PGLs by GAPP was well differentiated in sigmoid PGL versus poorly differentiated in rectal PGL. Although these PGLs were the same Stage II of TNM classification, the patient with sigmoid colon PGL had neither recurrence nor metastasis for 5 years after the operation, however, the patient with rectal PGL suffered the recurrent multiple metastases and expired 5 years after the operation. Herein, we compared these colorectal PGLs in regard to the patients' prognostic factors. Patient prognosis with these colorectal PGLs was mostly related to the tumor size and histologic grade under the same situation of SDH-deficiency.

A fascinating class of familial paraganglioma (PGL) neuroendocrine tumors is driven by the loss of the tricarboxylic acid (TCA) cycle enzyme succinate dehydrogenase (SDH) resulting in succinate accumulation as an oncometabolite and other metabolic derangements. Here, we exploit a Saccharomyces cerevisiae yeast model of SDH loss where accumulating succinate, and possibly reactive oxygen species, poison a dioxygenase enzyme required for sulfur scavenging. Using this model, we performed a chemical suppression screen for compounds that relieve dioxygenase inhibition. After testing 1280 pharmaceutically active compounds, we identified meclofenoxate HCl and its hydrolysis product, dimethylaminoethanol (DMAE), as suppressors of dioxygenase intoxication in SDH-loss yeast cells. We show that DMAE acts to alter metabolism so as to normalize the succinate:2-ketoglutarate ratio, improving dioxygenase function. This study raises the possibility that oncometabolite effects might be therapeutically suppressed by drugs that rewire metabolism to reduce the flux of carbon into pathological metabolic pathways.

Therapies for metastatic SDHB-dependent pheochromocytoma and paraganglioma (PPGL) are limited and poorly efficient. New targeted therapies and identification of early non-invasive biomarkers of response are thus urgently needed for these patients. We characterized an in vivo allograft model of spontaneously immortalized murine chromaffin cells (imCC) with inactivation of the Sdhb gene by dynamic contrast-enhanced MRI (DCE-MRI) and 18FDG-PET. We evaluated the response to several therapies: IACS-010759 (mitochondrial respiratory chain complex I inhibitor), sunitinib (tyrosine kinase inhibitor with anti-angiogenic activity), talazoparib (poly ADP ribose polymerase (PARP) inhibitor) combined or not to temozolomide (alkylating agent), pharmacological inhibitors of HIF2a (PT2385 and PT2977 (belzutifan)) and molecular inactivation of HIF2a (imCC Sdhb-/- shHIF2a). Multimodal imaging was performed, including magnetic resonance spectroscopy (1H-MRS) to monitor the level of succinate in vivo. The allografted model of Sdhb-/- imCC reflected SDHB-deficient tumors, with increased angiogenesis and a particular avidity for 18FDG. After 14 days of treatment, IACS-010759, sunitinib and talazoparib at high doses allowed a significant reduction of the tumor volumes. In contrast to the tumor growth inhibition observed in Sdhb-/- shHIF2a imCC tumors, pharmacological inhibitors of HIF2a (PT2385 and belzutifan) showed no antitumor action in this model, alone or in combination with sunitinib. 1H-MRS, but not DCE-MRI, enabled the monitoring response to sunitinib, which was the best treatment in this study, promoting a decrease in succinate levels detected in vivo. This study paves the way for new therapeutic options and reveals a potential new early biomarker of response to treatment in SDHB-dependent PPGL.

Aggressive pheochromocytomas and paragangliomas (PPGLs) are difficult to treat, and molecular targeting is being increasingly considered, but with variable results. This study investigates established and novel molecular-targeted drugs and chemotherapeutic agents for the treatment of PPGLs in human primary cultures and murine cell line spheroids. In PPGLs from 33 patients, including 7 metastatic PPGLs, we identified germline or somatic driver mutations in 79% of cases, allowing us to assess potential differences in drug responsivity between pseudohypoxia-associated cluster 1-related (n = 10) and kinase signaling-associated cluster 2-related (n = 14) PPGL primary cultures. Single anti-cancer drugs were either more effective in cluster 1 (cabozantinib, selpercatinib, and 5-FU) or similarly effective in both clusters (everolimus, sunitinib, alpelisib, trametinib, niraparib, entinostat, gemcitabine, AR-A014418, and high-dose zoledronic acid). High-dose estrogen and low-dose zoledronic acid were the only single substances more effective in cluster 2. Neither cluster 1- nor cluster 2-related patient primary cultures responded to HIF-2a inhibitors, temozolomide, dabrafenib, or octreotide. We showed particular efficacy of targeted combination treatments (cabozantinib/everolimus, alpelisib/everolimus, alpelisib/trametinib) in both clusters, with higher efficacy of some targeted combinations in cluster 2 and overall synergistic effects (cabozantinib/everolimus, alpelisib/trametinib) or synergistic effects in cluster 2 (alpelisib/everolimus). Cabozantinib/everolimus combination therapy, gemcitabine, and high-dose zoledronic acid appear to be promising treatment options with particularly high efficacy in SDHB-mutant and metastatic tumors. In conclusion, only minor differences regarding drug responsivity were found between cluster 1 and cluster 2: some single anti-cancer drugs were more effective in cluster 1 and some targeted combination treatments were more effective in cluster 2.

Germline mutations in more than 20 genes, including those encoding for the succinate dehydrogenase (SDH), predispose to rare tumours, such as pheochromocytoma/paraganglioma (PPGL). Despite encoding for the same enzymatic complex, SDHC and SDHD mutated PHEO/PGLs are generally benign, while up to 80% of SDHB mutated ones are malignant. In this study, we evaluated the different effects of tumour microenvironment on tumour cell migration/invasion, by co-culturing SDHB or SDHD silenced tumour spheroids with primary cancer-associated fibroblasts (CAFs). We observed that SDHD silenced spheroids had an intermediate migration pattern, compared to the highest migration capability of SDHB and the lowest one of the wild type (Wt) spheroids. Interestingly, we noticed that co-culturing Wt, SDHB and SDHD silenced spheroids with CAFs in low glucose (1 g/l) medium, caused a decreased migration of all the spheroids, but only for SDHB silenced ones this reduction was significant. Moreover, the collective migration, observed in high glucose (4.5 g/l) and characteristic of the SDHB silenced cells, was completely lost in low glucose. Importantly, migration could not be recovered even adding glucose (3.5 g/l) to low glucose conditioned medium. When we investigated cell metabolism, we found that low glucose concentration led to a reduction of oxygen consumption rate (OCR), basal and maximal oxidative metabolism, and ATP production only in CAFs, but not in tumour cells. These results suggest that CAFs metabolism impairment was responsible for the decreased invasion process of tumour cells, most likely preventing the release of the pro-migratory factors produced by CAFs. In conclusion, the interplay between CAFs and tumour cells is distinctive depending on the gene involved, and highlights the possibility to inhibit CAF-induced migration by impairing CAFs metabolism, indicating new potential therapeutic scenarios for medical therapy., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Abstract: Glomus tumors are rare, slow-growing extra-adrenal paragangliomas of the head and neck. Treatment and prevention of neurological deficits become more difficult as these tumors aggressively grow in size and infiltrate adjacent anatomical structures. Because glomus tumors are paragangliomas of neuroendocrine origin, 68Ga-DOTATATE PET/CT can be used as imaging method in the diagnosis and follow-up. In this case, we presented a recurrent glomus jugulare tumor that invaded to the cerebellum on 68Ga-DOTATATE PET/CT imaging., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Pheochromocytomas and paragangliomas (PCPG) are rare catecholamine-secreting endocrine tumors deriving from chromaffin cells of the embryonic neural crest. Although distinct molecular PCPG subtypes have been elucidated, certain characteristics of these tumors have yet to be fully examined, namely the tumor microenvironment (TME). To further understand tumor-stromal interactions in PCPG subtypes, the present study deconvoluted bulk tumor gene expression to examine ligand-receptor interactions., Methods: RNA-sequencing data primary solid PCPG tumors were derived from The Cancer Genome Atlas (TCGA). Tumor purity was estimated using two robust algorithms. The tumor purity estimates and bulk tumor expression values allowed for non-negative linear regression to predict the average expression of each gene in the stromal and tumor compartments for each PCPG molecular subtype. The predicted expression values were then used in conjunction with a previously curated ligand-receptor database and scoring system to evaluate top ligand-receptor interactions., Results: Across all PCPG subtypes compared to normal samples, tumor-to-tumor signaling between bone morphogenic proteins 7 (BMP7) and 15 (BMP15) and cognate receptors ACVR2B and BMPR1B was increased. In addition, tumor-to-stroma signaling was enriched for interactions between predicted tumor-originating delta-like ligand 3 (DLL3) and predicted stromal NOTCH receptors. Stroma-to-tumor signaling was enriched for interactions between ephrins A1 and A4 with ephrin receptors EphA5, EphA7, and EphA8. Pseudohypoxia subtype tumors displayed increased predicted stromal expression of genes related to immune-exhausted T-cell response, including those for inhibitory receptors HAVCR2 and CTLA4., Conclusion: The current exploratory study predicted stromal and tumor through compartmental deconvolution and yielded previously unrecognized interactions and putative biomarkers in PCPG., (© 2021. Italian Society of Endocrinology (SIE).)

Germline or somatic driver mutations linked to specific phenotypic features are identified in approximately 70% of all catecholamine-producing pheochromocytomas and paragangliomas (PPGLs). Mutations leading to stabilization of hypoxia-inducible factor 2α (HIF2α) and downstream pseudohypoxic signaling are associated with a higher risk of metastatic disease. Patients with metastatic PPGLs have a variable prognosis and treatment options are limited. In most patients with PPGLs, germline mutations lead to the stabilization of HIF2α. Mutations in HIF2α itself are associated with adrenal pheochromocytomas and/or extra-adrenal paragangliomas and about 30% of these patients develop metastatic disease; nevertheless, the frequency of these specific mutations is low (1.6-6.2%). Generally, mutations that lead to stabilization of HIF2α result in distinct catecholamine phenotype through blockade of glucocorticoid-mediated induction of phenylethanolamine N-methyltransferase, leading to the formation of tumors that lack epinephrine. HIF2α, among other factors, also contributes importantly to the initiation of a motile and invasive phenotype. Specifically, the expression of HIF2α supports a neuroendocrine-to-mesenchymal transition and the associated invasion-metastasis cascade, which includes the formation of pseudopodia to facilitate penetration into adjacent vasculature. The HIF2α-mediated expression of adhesion and extracellular matrix genes also promotes the establishment of PPGL cells in distant tissues. The involvement of HIF2α in tumorigenesis and in multiple steps of invasion-metastasis cascade underscores the therapeutic relevance of targeting HIF2α signaling pathways in PPGLs. However, due to emerging resistance to current HIF2α inhibitors that target HIF2α binding to specific partners, alternative HIF2α signaling pathways and downstream actions should also be considered for therapeutic intervention., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Objective: We aimed to retrospectively collect pathologically identified pheochromocytoma and paraganglioma (PPGL) tumor tissues from our center and investigate the expression of apelin and succinyl-CoA synthetase subunit beta (SUCLG2), human epidermal growth factor receptor-2 (HER2 or ERBB-2), contactin 4 (CNTN4), chromogranin B (CHGB), and succinate dehydrogenase B (SDHB) in metastatic and non-metastatic PPGLs, for exploring their roles in the diagnosis of metastatic PPGLs., Methods: A total of 369 patients with pathologically and surgically confirmed PPGLs at Xiangya Hospital, Central South University, between June 2010 and June 2020 were retrospectively included. Sixty patients-12 patients with metastatic PPGLs and 48 patients with non-metastatic PPGLs-were selected through propensity score matching (1:4) to reduce the effect of PPGL type, sex, and age. We observed and quantified the expression of apelin, SDHB, CHGB, ERBB-2, CNTN4, and SUCLG2 in paraffin-embedded samples using immunohistochemical staining., Results: No significant differences were observed between the metastatic group and non-metastatic group with respect to the expression of CNTN4 and SUCLG2. The expression of apelin, SDHB, CHGB, and ERBB-2 was significantly different between the two groups. The expression of apelin, SDHB, and CHGB was significantly lower in the metastatic group than that in the non-metastatic group (P < 0.001). ERBB-2 expression was significantly higher in the metastatic group than in the non-metastatic group (P = 0.042). Kaplan-Meier analysis revealed that patients with negative expression of apelin, SDHB, and CHGB showed significantly lower metastasis-free survival than those with positive expression. Multivariate Cox analysis revealed that SDHB and CHGB levels were independently associated with metastasis-free survival., Conclusion: The expression levels of apelin, CHGB, SDHB, and ERBB-2 may be predictive biomarkers for the diagnosis of metastatic PPGLs. Patients with negative expression of apelin, CHGB, and SDHB should be subjected to frequent postoperative follow-up procedures., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wang, Chen, Pang, Xu, Guan and Liu.)

Background: Practice guidelines to identify individuals with hereditary pheochromocytomas and paragangliomas (PPGLs) advocate for sequential gene testing strategy guided by specific clinical features and predate the routine use of multigene panel testing (MGPT)., Objective: To describe results of MGPT for hereditary PPGL in a clinically and ancestrally diverse cohort., Setting: Commercial laboratory based in the United States., Methods: Clinical data and test results were retrospectively reviewed in 1727 individuals who had targeted MGPT from August 2013 through December 2019 because of a suspicion of hereditary PPGL., Results: Overall, 27.5% of individuals had a pathogenic or likely pathogenic variant (PV), 9.0% had a variant of uncertain significance, and 63.1% had a negative result. Most PVs were identified in SDHB (40.4%), followed by SDHD (21.1%), SDHA (10.1%), VHL (7.8%), SDHC (6.7%), RET (3.7%), and MAX (3.6%). PVs in FH, MEN1, NF1, SDHAF2, and TMEM127 collectively accounted for 6.5% of PVs. Clinical predictors of a PV included extra-adrenal location, early age of onset, multiple tumors, and positive family history of PPGL. Individuals with extra-adrenal PGL and a positive family history were the most likely to have a PV (85.9%). Restricting genetic testing to SDHB/C/D misses one-third (32.8%) of individuals with PVs., Conclusion: Our data demonstrate a high diagnostic yield in individuals with and without established risk factors, a low inconclusive result rate, and a substantial contribution to diagnostic yield from rare genes. These findings support universal testing of all individuals with PPGL and the use of concurrent MGPT as the ideal platform., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society.)

Rationale: Gangliocytic paraganglioma (GP) is a rare tumor that mostly develops in the duodenum and is composed of the following 3 cell types: epithelioid endocrine, spindle-like, and ganglion-like cells. It manifests as symptoms such as abdominal pain, gastrointestinal bleeding, and weight loss; however, occasionally, it is incidentally detected on endoscopic or radiologic examinations. Although GP is usually benign, it can metastasize to the lymph nodes, and distant metastases have been reported in some cases., Patient Concerns: A 46-year-old woman presented with anemia on health surveillance examination. She had no other specific symptoms, and her physical examination did not reveal any abnormal finding., Diagnosis: Endoscopic ultrasound-guided fine-needle aspiration biopsy was performed, and the endoscopist obtained samples from the inner side of the ampullary mass. Pathological examination suggested GP or a neuroendocrine tumor., Interventions: Initially, we planned transduodenal ampullectomy with lymph node excision. However, there was severe fibrosis around the duodenum, and an examination of a frozen biopsy sample from the periduodenal lymph node showed atypical cells in the lymph node. Therefore, we performed pylorus-preserving pancreaticoduodenectomy with lymph node dissection., Outcomes: The final pathological diagnosis was GP located in the ampulla of Vater. The GP showed lymphovascular and perineural invasion and invaded the duodenal wall. Furthermore, 4 out of 18 harvested lymph nodes showed metastasis., Lessons: We described a case of GP confined to the ampulla with regional lymph node metastasis and reviewed published literature on ampullary GP with lymph node metastasis., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors with metastatic potential. Both 68Ga-DOTATATE and 18F-FDG PET/CT scans have been demonstrated to have important roles in imaging PPGLs, but less is known about the performance of PET/MRI for PPGLs. The study is aimed to investigate whether diffusion-weighted imaging-MRI (DWI-MRI) has an added value to PET imaging in the identification of PPGL lesions by means of integrated PET/MRI., Methods: Eleven patients who underwent both 18F-FDG and 68Ga-DOTATATE PET/MRI within 2 weeks were retrospectively included in the study. A total of 56 PPGL lesions were analyzed, and lesion-based detection rates of 68Ga-DOTATATE PET, 18F-FDG PET, DWI-MRI, and PET/MRI were calculated and compared, respectively., Results: 68Ga-DOTATATE PET was superior to 18F-FDG PET and DWI-MRI in imaging PPGLs with a lesion-based detection rate of 96.4% (54/56) (95% confidence interval [CI], 87.7%-99.6%), 85.7% (48/56) (95% CI, 76.3%-95.2%), and 89.3% (50/56) (95% CI, 80.9%-97.6%), respectively. PET/MRI with DWI could improve the detection rate of 68Ga-DOTATATE and 18F-FDG PET alone up to 100% in metastatic PPGLs. Lesions of PPGL demonstrated markedly higher tracer uptake in 68Ga-DOTATATE PET than in 18F-FDG PET (P = 0.009 for primary lesion, P = 0.033 for metastases)., Conclusions: 68Ga-DOTATATE PET showed a higher detection rate than 18F-FDG for PPGLs. In integrated PET/MRI, MRI had an added value to 18F-FDG PET but not much to 68Ga-DOTATATAE PET in identifying PPGL lesions., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Phaeochromocytomas and paragangliomas (PPGL) are rare, but strongly heritable tumours. Variants in succinate dehydrogenase (SDH) subunits are identified in approximately 25% of cases. However, clinical and genetic information of patients with SDHC variants are underreported., Design: This retrospective case series collated data from 18 UK Genetics and Endocrinology departments., Patients: Both asymptomatic and disease-affected patients with confirmed SDHC germline variants are included., Measurements: Clinical data including tumour type and location, surveillance outcomes and interventions, SDHC genetic variant assessment, interpretation, and tumour risk calculation., Results: We report 91 SDHC cases, 46 probands and 45 non-probands. Fifty-one cases were disease-affected. Median age at genetic diagnosis was 43 years (range: 11-79). Twenty-four SDHC germline variants were identified including six novel variants. Head and neck paraganglioma (HNPGL, n = 30, 65.2%), extra-adrenal paraganglioma (EAPGL, n = 13, 28.2%) and phaeochromocytomas (PCC) (n = 3, 6.5%) were present. One case had multiple PPGLs. Malignant disease was reported in 19.6% (9/46). Eight cases had non-PPGL SDHC-associated tumours, six gastrointestinal stromal tumours (GIST) and two renal cell cancers (RCC). Cumulative tumour risk (95% CI) at age 60 years was 0.94 (CI: 0.79-0.99) in probands, and 0.16 (CI: 0-0.31) in non-probands, respectively., Conclusions: This study describes the largest cohort of 91 SDHC patients worldwide. We confirm disease-affected SDHC variant cases develop isolated HNPGL disease in nearly 2/3 of patients, EAPGL and PCC in 1/3, with an increased risk of GIST and RCC. One fifth developed malignant disease, requiring comprehensive lifelong tumour screening and surveillance., (© 2021 John Wiley & Sons Ltd.)

Background: Pheochromocytomas (PCC) and paragangliomas (PGL) are catecholamine-producing neuroendocrine tumors. According to the World Health Organization Classification 2017, all PCC/PGL are considered to have malignant potential. There is growing evidence that PCC/PGL represent a metabolic disease that leads to aerobic glycolysis. Cellular energy metabolism involves both transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and succinate dehydrogenase (SDH) subtypes, but the association of these substances with PCC/PGL is largely unknown., Methods: We investigated SDHB gene mutation and protein expressions for SDHB and Nrf2 in surgical specimens from 29 PCC/PGL. We also assessed preoperative maximum standard glucose uptake (SUVmax) on [ 18 F]fluorodeoxy-glucose positron emission tomography and mRNA levels for Nrf2., Results: Among 5 PCC/PGL with a PASS Score ≥ 4 or with a moderately to poorly differentiated type in the GAPP Score, 4 were metastatic and found to be SDHB mutants with homogeneous deletion of SDHB protein. SDHB mutants showed a higher expression of Nrf2 protein and a higher preoperative SUVmax than non-SDHB mutants with a PASS < 4 or a well-differentiated GAPP type. Furthermore, protein expression of Nrf2 was positively associated with preoperative SUVmax. The Nrf2 mRNA level positively correlated with malignant phenotype, higher expression for Nrf2 protein and SDHB gene mutant, but negatively correlated with expression for SDHB protein. There was also a positive correlation between Nrf2 mRNA level and SUVmax., Conclusion: These results suggest that activation of Nrf2 and elevated metabolism play roles in PCC/PGL with malignant potential that have SDHB gene mutation and SDHB deficiency., (© 2022. The Author(s).)

Objective: The purpose of this study is to investigate the incidence of recurrence or metastasis of pheochromocytoma/paraganglioma (PPGL) patients after primary tumor resection, and to compare the differences of clinical indicators between patients with or without recurrence or metastasis. Methods: This study is a retrospective study. All 157 patients were followed up after tumor resection in Peking Union Medical College Hospital from 2008 to 2016. We obtained the basic information [age of diagnosis, gender, height, weight and body mass index (BMI)], the onset status of PPGL (age of onset, course of disease, family history, tumor location, whether the tumor is bilateral or multiple, and preoperative blood pressure), clinical and pathological features of PPGL tumor (tumor size, whether it could adhere, invade or infiltrate during operation, whether the tumor capsule is smooth and complete on the postoperative pathological diagnosis, whether there is infiltration growth and cystic necrosis on tumor pathology and Ki-67 index), and laboratory examination results [24 hours urinary norepinephrine (NE), epinephrine (E), dopamine (DA) before operation]. According to the outpatient or telephone follow-up, the postoperative incidences of recurrence and metastasis were explored, and the basic information, status of onset, clinical and pathological characteristics of tumors, and laboratory test results of patients were compared. Results: A total of 157 patients, 69 males and 88 females, were with an average age of (42.4±13.4) years old. There were 103 patients with PCC and 54 with PGL. The average follow-up time was (9.5±2.0) years. Of the 103 patients with PCC, 13 (12.6%) had postoperative recurrence and 9 (8.7%) had distant metastasis. Compared with the patients without recurrence and metastasis, the onset age of the 13 patients with recurrence was younger [(27.3±15.7) years vs (39.3±12.2) years, P =0.003], the course of disease was longer [48.0 (23.0, 141.0) months vs 12.0 (4.0, 60.0) months, P =0.010]. The tumor size of 9 patients with distant metastasis was larger [8.0 (6.1, 12.8) cm vs 5.0 (4.0, 7.0) cm, P =0.027]. Of the 54 patients with PGL, 8 (14.8%) had postoperative recurrence and 5 (9.3%) had distant metastasis. Compared with the patients without recurrence and metastasis, the course of disease of the 8 patients with recurrence was longer [90.0 (36.3, 165.0) months vs 24.0 (8.0, 72.0) months, P =0.009], and the proportion of primary tumors with multiple lesions was higher (4/8 vs 4.4%, P =0.003). The preoperative diastolic blood pressure was higher in 5 patients with distant metastasis [(146.0±32.1) mmHg vs (120.6±25.3) mmHg, P =0.043] (1 mmHg=0.133 kPa), and the proportion of primary tumors with multiple lesions was higher (2/4 vs 4.4%, P =0.029). Conclusion: PPGL patients are prone to have recurrence or metastasis. PPGL patients with postoperative recurrence or distant metastasis had younger onset age, longer course of disease, larger tumor size and higher proportion of multiple lesions.

Objective: To investigate possible predictive factors of catecholamine-induced cardiomyopathy in pheochromocytoma and paraganglioma (CICMPP) patients., Methods: In all, 50 CICMPP patients and 152 pheochromocytoma and paraganglioma (PPGL) patients without CICMPP who were treated in our institution between August 2012 and April 2018 were included in this retrospective study to assess predictors of CICMPP., Results: Patients with CICMPP reported younger onset age, more clinical symptoms and signs, more family history of hypertension, and higher maximum systolic, diastolic, and mean BP and maximum HR. Medical evaluation also showed higher level of blood hematocrit, blood glucose, 24-h urine catecholamines, larger diameter of the tumor and more comorbidities, von Hippel-Lindau syndromes, and metastatic tumors in these patients. Multivariable analysis identified maximum resting HR over 115 beats/min (OR 10.05, 95% CI 3.71-27.20), maximum resting systolic BP over 180 mmHg (OR 7.17, 95% CI 2.22-23.23), blood glucose over 8.0 mmol/L (OR 6.52, 95% CI 2.25-18.86), more than 3 symptoms and signs (OR 6.05, 95% CI 1.86-19.64), and onset age under 40 years (OR 3.74, 95% CI 1.37-10.20) as independent predictors of CICMPP. Female sex (OR 5.06, 95% CI 1.19-21.54), complaint of chest pain (OR 5.84, 95% CI 1.27-26.90), and extra-adrenal tumor (OR 8.64, 95% CI 1.82-40.94) were independent predictors of Takotsubo cardiomyopathy in CICMPP., Conclusion: Maximum resting HR ≥115 beats/min, maximum resting systolic BP ≥180 mmHg, blood glucose ≥8.0 mmol/L, number of symptoms and signs ≥3, and onset age ≤40 years were found to be predictive factors for CICMPP., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wang, Yu and Huang.)

Succinate dehydrogenase (SDH) is a mitochondrial enzyme that participates in both the tricarboxylic acid cycle and the electron transport chain. Mutations in genes encoding SDH are responsible for a predisposition to pheochromocytomas and paragangliomas, and more rarely, to gastrointestinal stromal tumors or renal cell carcinomas. A decrease in SDH activity, not explained by genetics, has also been observed in more common cancers. One of the consequences of the inactivation of SDH is the excessive production of its substrate, succinate, which acts as an oncometabolite by promoting a pseudohypoxic status and an extensive epigenetic rearrangement. Understanding SDH-related oncogenesis now makes it possible to develop innovative diagnostic methods and to consider targeted therapies for the management of affected patients., (© 2022 médecine/sciences – Inserm.)

Carotid body tumors, rare neck paragangliomas arising from the common carotid artery bifurcation, can be classified as sporadic, hyperplastic, or familial. The familial type is often bilateral and associated with germline mutation of the mitochondrial enzyme succinate dehydrogenase. We report the rare case of a 42-year-old man who presented with bilateral giant familial carotid body tumors associated with a concomitant skull-base paraganglioma, left-sided facial nerve palsy, and an incomplete circle of Willis. We describe the excision of the tumors in 2 stages (the left mass and associated paraganglioma first and the right mass second), 6 months apart, with use of general anesthesia, and we discuss other operative considerations., (© 2022 by the Texas Heart® Institute, Houston.)

Paraganglioma that involves the CNS may mimic clinico-radiologically many other commoner entities. The current study presents a wide view of the clinical, radiological, and histomorphological spectrum along with rare associations that can occur concurrently with this lesion. The most common site of infliction in CNS is the spine and, in the current series, involvement of the lumbar spine was most frequent. Both clinical and radiological features point towards other more common differentials, including neurofibroma/schwannoma and ependymoma. Some studies suggest rich vascularity (cap sign) and salt pepper appearance in T2-weighted images to serve as soft pointers towards diagnosing it on magnetic resonance imaging, however, in our series we did not encounter the same.

Purpose: Paraganglioma of the urinary bladder (UBPGL) is a rare neuroendocrine tumor diagnosed in many patients only after surgery. We, therefore, assessed clinical clues relevant to presurgical diagnosis and clinical consequences in patients with a missed presurgical diagnosis of UBPGL., Materials and Methods: Case reports describing a UBPGL (published from 1-1-2001 and 31-12-2020) were identified in Pubmed. Two authors independently performed data extraction and assessed data quality according to the PRISMA guideline. Patients were divided into two groups: UBPGL diagnosis before and after surgery., Results: We included 177 articles reporting 194 cases. In 90 (46.4%) patients, the UBPGL was diagnosed before and in 104 (53.6%) after surgery. In presurgically diagnosed UBPGL, hypertension and catecholamine-associated symptoms were 2- to 3-fold (p < 0.001) more frequent than in postsurgically diagnosed patients whereas hematuria was twofold (p = 0.003) more prevalent in those with postsurgical diagnosis. Hypertension was an independent factor for presurgical biochemical testing (OR 4.45, 95% CI 1.66-11.94) while hematuria (OR 0.23, 95% CI 0.09-0.60) was an independent factor for not performing presurgical biochemical testing. Most patients diagnosed after surgery were not pretreated with alpha-adrenoceptor blockade (95.2%), underwent more frequently transurethral resection instead of cystectomy (70.2% vs. 23.1%) and had more frequent peroperative complications and residual tumor mass., Conclusions: In nearly half of all patients with a UBPGL, the diagnosis was not established before surgery. Hypertension and hematuria contributed independently to a presurgical diagnosis. Postsurgical diagnosis, which was associated with suboptimal presurgical and surgical management, resulted in more peroperative complications and incomplete tumor resections., (© 2021. The Author(s).)