Pheochromocytoma and Paraganglioma

Anaesthetic management of a dopamine-secreting phaeochromocytoma

Pheochromocytomas are rare neuroendocrine tumors that arise from chromaffin cells of the adrenal medulla. Most adrenal pheochromocytomas secrete norepinephrine and epinephrine. Dopamine secreting pheochromocytomas are extremely rare and differs from classic pheochromocytomas in clinical features, posing a significant diagnostic challenge. A 41-year-old women presented to our emergency department because of acute flank colic pain and normotension. The screening abdominal computed tomography scan revealed a left adrenal mass. The laboratory test showed significantly increase in plasma dopamine and 24-hour urine dopamine. During surgical removal the patient remained hypotensive requiring doses of norepinephrine. The patient presented significant hypertensive responde during direct laryngoscopy and intubation.

[Molecular genetics of human hypertension]

A genetic influence on blood pressure was demonstrated more than 100 years ago and a simple Mendelian inheritance was initially presumed. Platt and Pickering conducted a lively debate on this topic. Platt favored the idea that a single gene or only a few genes were responsible for high blood pressure. Pickering presented research results, which supported the assumption that many genes exerted an influence on blood pressure. This was all in a period when it was not even known what genes were. Genome-wide association studies (GWAS) according to the Pickering model have identified > 500 blood pressure relevant gene loci, which are distributed over the whole genome. Each individual gene exerts only a small effect on blood pressure. The dark horses of hypertension research are the secondary causes. In pheochromocytoma, primary aldosteronism, Cushing's syndrome and even fibromuscular dysplasia (renovascular hypertension) the results indicate that a genetic cause regularly underlies secondary hypertension. This would therefore also partially confirm Platt's theory. In the meantime, a multitude of forms of hypertension have been described with a genetic inheritance according to Mendel. Each of these genetic variants exerts a considerable influence on blood pressure. A multitude of novel physiological mechanisms were explained by this. These findings will become therapeutically important. Therefore, it is incumbent upon clinicians to be optimally informed about these research results.

Consensus on molecular imaging and theranostics in neuroendocrine neoplasms

Nuclear medicine plays an increasingly important role in the management neuroendocrine neoplasms (NEN). Somatostatin analogue (SSA)-based positron emission tomography/computed tomography (PET/CT) and peptide receptor radionuclide therapy (PRRT) have been used in clinical trials and approved by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA). European Association of Nuclear Medicine (EANM) Focus 3 performed a multidisciplinary Delphi process to deliver a balanced perspective on molecular imaging and radionuclide therapy in well-differentiated neuroendocrine tumours (NETs). NETs form in cells that interact with the nervous system or in glands that produce hormones. These cells, called neuroendocrine cells, can be found throughout the body, but NETs are most often found in the abdomen, especially in the gastrointestinal tract. These tumours may also be found in the lungs, pancreas and adrenal glands. In addition to being rare, NETs are also complex and may be difficult to diagnose. Most NETs are non-functioning; however, a minority present with symptoms related to hypersecretion of bioactive compounds. NETs often do not cause symptoms early in the disease process. When diagnosed, substantial number of patients are already found to have metastatic disease. Several societies' guidelines address Neuroendocrine neoplasms (NENs) management; however, many issues are still debated, due to both the difficulty in acquiring strong clinical evidence in a rare and heterogeneous disease and the different availability of diagnostic and therapeutic options across countries. EANM Focus 3 reached consensus on employing ⁶⁸gallium-labelled somatostatin analogue ([⁶⁸Ga]Ga-DOTA-SSA)-based PET/CT with diagnostic CT or magnetic resonance imaging (MRI) for unknown primary NET detection, metastatic NET, NET staging/restaging, suspected extra-adrenal pheochromocytoma/paraganglioma and suspected paraganglioma. Consensus was reached on employing ¹⁸fluorine-fluoro-2-deoxyglucose ([¹⁸F]FDG) PET/CT in neuroendocrine carcinoma, G3 NET and in G1-2 NET with mismatched lesions (CT-positive/[⁶⁸Ga]Ga-DOTA-SSA-negative). Peptide receptor radionuclide therapy (PRRT) was recommended for second line treatment for gastrointestinal NET with [⁶⁸Ga]Ga-DOTA-SSA uptake in all lesions, in G1/G2 NET at disease progression, and in a subset of G3 NET provided all lesions are positive at [¹⁸F]FDG and [⁶⁸Ga]Ga-DOTA-SSA. PRRT rechallenge may be used for in patients with stable disease for at least 1 year after therapy completion. An international consensus is not only a prelude to a more standardised management across countries but also serves as a guide for the direction to follow when designing new research studies.

Acute hypertensive crisis due to newly diagnosed pheochromocytoma in the ninth decade of life: an unusual presentation

The patient is an 85-year-old man with multiple comorbidities, including hypertension and coronary artery disease with recent myocardial infarction who underwent cardiac catheterisation. During the procedure, the patient developed profound hypertensive crisis with flash pulmonary oedema, requiring significant intervention for blood pressure (BP) control. His crisis was also marked by wide excursions in his BP. The patient was found to have a large left adrenal mass measuring 9.4×8.7×8.1 cm, with biochemical testing confirming the suspicion of pheochromocytoma. Alpha-blockade was started prior to availability of lab results due to high index of suspicion. Surgical removal, the mainstay of treatment, has yet to transpire as he has no family, and due to his underlying dementia, he was not felt to have capacity for decision-making at the time of diagnosis. The case elucidates the vast presentations of this tumour, the means of diagnosis and the difficulties of treatment.

Pregnancy and phaeochromocytoma/paraganglioma: clinical clues affecting diagnosis and outcome - a systematic review

BACKGROUND

Phaeochromocytoma and paraganglioma (PPGL) in pregnancy, if not diagnosed antepartum, pose a high risk for mother and child.

OBJECTIVE

To examine the clinical clues of antepartum and postpartum/postmortem diagnosis of PPGL.

SEARCH STRATEGY

Case reports on PPGL in pregnancy published between 1 January 1988 and 30 June 2019 in English, German, Dutch or French.

SELECTION CRITERIA

Case reports containing a predefined minimum of clinical data on PPGL and pregnancy.

DATA COLLECTION AND ANALYSIS

Two authors independently performed data extraction and assessed data quality. We calculated odds ratios (OR) (with 95% confidence intervals) and used uni- and multivariable logistic regression analysis.

MAIN RESULTS

Maternal and fetal/neonatal mortalities were 9.0% (18/200) and 14.2% (29/204), respectively. Maternal mortality was 42-fold higher with PPGL diagnosed postpartum/postmortem (17/58; 29.3%) than antepartum (1/142; 0.7%) (adjusted OR 45.9, 95% CI 5.67-370, P = 0.0003). Offspring mortality was 2.6-fold higher with PPGL diagnosed postpartum/postmortem than antepartum (OR 3.1, 95% CI 1.38-6.91, P = 0.0044). Hypertension at admission (OR 2.29, 95% CI 1.12-4.68, P = 0.022), sweating (OR 3.14, 95% CI 1.29-7.63, P = 0.014) and a history of PPGL, a known PPGL-associated gene mutation or adrenal mass (OR 8.87, 95% CI 1.89-41.64, P = 0.0056) were independent factors of antepartum diagnosis. Acute onset of symptoms (OR 8.49, 95% CI 3.52-20.5, P < 0.0001), initial diagnosis of pre-eclampsia (OR 6.34, 95% CI 2.60-15.5, P < 0.0001), admission for obstetric care (OR 10.71, 95% CI 2.70-42.45, P = 0.0007) and maternal tachycardia (OR 2.72, 95% CI 1.26-5.85, P = 0.011) were independent factors of postpartum diagnosis.

CONCLUSION

Several clinical clues can assist clinicians in considering an antenatal diagnosis of PPGL in pregnancy, thus potentially improving outcome.

TWEETABLE ABSTRACT

Systematic review of 204 pregnant patients with phaeochromocytoma identified clinical clues for a timely antepartum diagnosis.

Germline DLST Variants Promote Epigenetic Modifications in Pheochromocytoma-Paraganglioma

CONTEXT

Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors in which altered central metabolism appears to be a major driver of tumorigenesis, and many PPGL genes encode proteins involved in the tricarboxylic acid (TCA) cycle.

OBJECTIVE/DESIGN

While about 40% of PPGL cases carry a variant in a known gene, many cases remain unexplained. In patients with unexplained PPGL showing clear evidence of a familial burden or multiple tumors, we aimed to identify causative factors using genetic analysis of patient DNA and functional analyses of identified DNA variants in patient tumor material and engineered cell lines.

PATIENTS AND SETTING

Patients with a likely familial cancer burden of pheochromocytomas and/or paragangliomas and under investigation in a clinical genetic and clinical research setting in university hospitals.

RESULTS

While investigating unexplained PPGL cases, we identified a novel variant, c.1151C>T, p.(Pro384Leu), in exon 14 of the gene encoding dihydrolipoamide S-succinyltransferase (DLST), a component of the multi-enzyme complex 2-oxoglutarate dehydrogenase. Targeted sequence analysis of further unexplained cases identified a patient carrying a tumor with compound heterozygous variants in DLST, consisting of a germline variant, c.1121G>A, p.(Gly374Glu), together with a somatic missense variant identified in tumor DNA, c.1147A>G, p.(Thr383Ala), both located in exon 14. Using a range of in silico and functional assays we show that these variants are predicted to be pathogenic, profoundly impact enzyme activity, and result in DNA hypermethylation.

CONCLUSIONS

The identification and functional analysis of these DLST variants further validates DLST as an additional PPGL gene involved in the TCA cycle.

Pseudotumoral form of schistosomiasis mimicking neuroendocrine tumor: a case report and brief review of the differential diagnosis of retroperitoneal masses

Differential diagnosis of retroperitoneal masses may become complex and requires careful anamnesis, physical examination and several complementary tests. We present the clinical case of a male patient aged 45 years who was diagnosed with a 4cm paraaortic lesion compatible with neuroendocrine tumor in the abdominal computed tomography (CT) exam. The workup performed with SPECT-CT, somatostatin receptors scintigraphy, MIBG scintigraphy, 24-hour urine total and fractionated catecholamines and 24-hour urine 5-OH indoleacetic did not confirm the first diagnostic impression. Finally, the lesion was biopsied and presence of micro-organisms was revealed. Further exams confirmed schistosomiasis as the cause of the paraaortic lesion. Histological diagnosis can be helpful with regard to the differential diagnosis of retroperitoneal masses.

From Diagnosis to Therapy-PET Imaging for Pheochromocytomas and Paragangliomas

PURPOSE OF REVIEW

Pheochromocytoma and paraganglioma (PPGLs) are neuroendocrine tumors with diverse clinical presentations. PPGLs can be sporadic but often are associated with various syndromes, which can have variable clinical presentations. A thorough workup is therefore critical for staging, treatment, and follow-up. Imaging is an essential part of the workup and diagnosis of PPGLs.

RECENT FINDINGS

Improvements in cross-sectional imaging with radionuclides have increased specificity and sensitivity for identifying and treating PPGLs. Furthermore, a variety of targets on PPGLs has allowed for optimal imaging with radionuclides that can be used for staging and treatment. Currently, radionuclides are being evaluated for staging and treatment of PPGLs. Developing novel radionuclides that can identify disease sites and target them simultaneously provides a potential for improving survival and outcomes in patients with PPGLs. Given the clinical diversity among PPGLs, expanding the therapeutic arsenal against locally advanced or metastatic PPGLs can allow clinicians to evaluate and treat PPGLs thoroughly.

Functional Malignant Retroperitoneal Paraganglioma with Liver Metastasis: a Rare Case Report

Paragangliomas are rare neoplasms. Their specific annual incidence is still unclear. These are rare neuroendocrine tumors which arise from extra-adrenal paraganglioma and they have the ability to secrete catecholamines. Most of them are diagnosed in the 3rd to 5th decades of life with mean age around 47 years. Majority of them are benign; however, malignant tumors with metastatic behavior are very rare. The incidence of malignant paraganglioma is estimated around 93/400 million people. The clinical course of metastatic malignant disease is variable and the reported 5-year survival is around 12-84%. There is no curative treatment option for malignant metastatic paraganglioma. If resectable, both, primary and metastasis should be resected. The only criteria which defines its malignancy is the presence of metastatic spread of chromaffin cells in tissues that normally do not contain such cells. Functional paraganglioma secretes excessive catecholamines which clinically manifest as paroxysmal hypertension, headache, sweating, and palpitations. We reported a case of young male who presented with huge left retroperitoneal mass and after evaluation found to have a functional malignant paraganglioma with liver metastasis. Surgical resection of the primary malignant paraganglioma with metastatectomy helps in decreasing the complications, improving the symptoms and prolonging the survival.

Case Report: An Unusual First Manifestation of a Pheochromocytoma

We present a 30-year old male presented with hemoptysis as a first manifestation and pulmonary CT scan characteristic of diffuse alveolar hemorrhage. Further abdominal examination discovered a left adrenal mass. Elevated catecholamine and metanephrine levels and subsequent adrenalectomy confirmed the diagnosis of pheochromocytoma. Symptoms of pheochromocytoma are highly variable, which could potentially delay the diagnosis. With careful investigation, emergency medicine practitioners need to be aware of the cunning and changeful manifestations in pheochromocytoma.

Case Report: Successful Control of Pulmonary Metastatic Pheochromocytoma With Iodine-125 Seed Implantation

Pheochromocytoma with lung metastases is rare in clinics, and the prognosis of metastatic pheochromocytoma is generally poor. In this case, a 57-year-old woman who presented with hypertension and palpitations was diagnosed with left adrenal pheochromocytoma with lung metastasis in 2010. The patient received left adrenalectomy for pheochromocytoma 10 years ago, but pulmonary lesions had significant progression 7 years ago. The patient was treated with iodine-125 (¹²⁵I) seed implantation for pulmonary lesions. All of the 5 pulmonary lesions achieved partial response 6 months later, further shrank 1 year later, and were successfully controlled for 7 years. This case indicated that ¹²⁵I seed implantation could be an alternative local therapy for metastatic pheochromocytoma in the lung.

Giant Paraganglioma Complicated With Catecholamine Crisis and Catecholamine Cardiomyopathy: A Case Report and Review of the Literature

BACKGROUND

Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors which overproduce catecholamines. Heart failure and myocardial infarction caused by paraganglioma complicated with catecholamine crisis are the most common causes of death in PPGL patients before surgery. When giant paraganglioma is complicated with catecholamine crisis, treatment brooks no delay.

CASE SUMMARY

A 49-year-old man had episodic sweating, tachycardia with irregular pulse, and headaches 5 days before, and then showed up with chest pain and wheezing for 1 day. Meanwhile, he developed symptoms of recurrent severe abdominal pain and loss of consciousness, and his blood pressure was severely unstable (from 70/40 to 300/200 mmHg). First, the electrocardiogram showed ventricular tachycardia, and then we noticed the waves of ST-segment elevation, but we did not find significant abnormalities in coronary angiography. Abdominal CT and MRI revealed a giant lesion with bleeding or infection in the retroperitoneal adrenal area. These imaging findings were confirmed during surgery, and there was vascular adhesion between the retroperitoneal tumor and the inferior vena cava and left and right renal vein. After the successful resection of the tumor, postoperative pathology confirmed paraganglioma, and the patient pulled through and was discharged quickly.

DISCUSSION

This is a rare case of giant paraganglioma complicated with catecholamine crisis and catecholamine cardiomyopathy. We can diagnosis this disease greatly by elevated norepinephrine, and it is a gold biochemical standard at present. Standard treatment is surgical resection, which is effective in treating this rare neuroendocrine tumor.

Recurrent Germline Mutations of CHEK2 as a New Susceptibility Gene in Patients with Pheochromocytomas and Paragangliomas

PURPOSE

Recently, pheochromocytomas and paragangliomas (PPGLs) have been strongly suspected as hereditary tumors, as approximately 40% of patients carry germline mutations. In the cancers where defects occur to corrupt DNA repair and facilitate tumorigenesis, a CHEK2 strong association has been observed. Therefore, the purpose of this study was to investigate the effect of CHEK2 mutations for its possible pathogenicity in PPGLs.

METHODS

Four patients with CHEK2 mutations were recruited, as previously detected by the whole exome sequencing. Sanger sequencing was used to verify the germline mutations as well as the loss of heterozygosities (LOHs) in their somatic DNAs. Immunohistochemistry was used to analyze the expression of CHEK2 and its downstream target p53 Ser20 (phosphorylated p53).

RESULTS

The average age of studied patients was 44.25 ± 11.18 years, at the time diagnosis. One patient had multiple tumors which recurred quickly, while two patients had distant metastasis. None of the patient had any relevant family history. Four germline CHEK2 mutations were identified (c.246_260del; c.715G > A; c.1008+3A > T; and c.1111C > T). All the patients were predicted to have either pathogenic or suspected pathogenic mutations. There was no LOH of CHEK2 gene in somatic DNAs found. Additionally, neither CHEK2 proteins nor its downstream target p53 Ser20 were expressed in the tumor tissues. The inactivation of CHEK2 leads to the decrease in the p53 phosphorylation, which might promote tumorigenesis.

CONCLUSIONS

For the first time, CHEK2 was identified as a susceptibility gene for PPGLs. However, the penetrance of CHEK2 gene with genotype-phenotype correlation needs to be investigated.

Maternal and fetal outcomes in phaeochromocytoma and pregnancy: a multicentre retrospective cohort study and systematic review of literature

BACKGROUND

Phaeochromocytoma or paraganglioma (collectively known as PPGL) in pregnant women can lead to severe complications and death due to associated catecholamine excess. We aimed to identify factors associated with maternal and fetal outcomes in women with PPGL during pregnancy.

METHODS

We did a multicentre, retrospective study of patients with PPGL and pregnancy between Jan 1, 1980, and Dec 31, 2019, in the International Pheochromocytoma and Pregnancy Registry and a systematic review of studies published between Jan 1, 2005, and Dec 27, 2019 reporting on at least five cases. The inclusion criteria were pregnancy after 1980 and PPGL before or during pregnancy or within 12 months post partum. Eligible patients from the retrospective study and systematic review were included in the analysis. Outcomes of interest were maternal or fetal death and maternal severe cardiovascular complications of catecholamine excess. Potential variables associated with these outcomes were evaluated by logistic regression.

FINDINGS

The systematic review identified seven studies (reporting on 63 pregnancies in 55 patients) that met the eligibility criteria and were of adequate quality. A further 197 pregnancies in 186 patients were identified in the International Pheochromocytoma and Pregnancy Registry. After excluding 11 pregnancies due to potential overlap, the final cohort included 249 pregnancies in 232 patients with PPGL. The diagnosis of PPGL was made before pregnancy in 37 (15%) pregnancies, during pregnancy in 134 (54%), and after delivery in 78 (31%). Of 144 patients evaluated for genetic predisposition for phaeochromocytoma, 95 (66%) were positive. Unrecognised PPGL during pregnancy (odds ratio 27·0; 95% CI 3·5-3473·1), abdominal or pelvic tumour location (11·3; 1·5-1440·5), and catecholamine excess at least ten-times the upper limit of the normal range (4·7; 1·8-13·8) were associated with adverse outcomes. For patients diagnosed during pregnancy, α-adrenergic blockade therapy was associated with fewer adverse outcomes (3·6; 1·1-13·2 for no α-adrenergic blockade vs α-adrenergic blockade), whereas surgery during pregnancy was not associated with better outcomes (0·9; 0·3-3·9 for no surgery vs surgery).

INTERPRETATION

Unrecognised and untreated PPGL was associated with a substantially higher risk of either maternal or fetal complications. Appropriate case detection and counselling for premenopausal women at risk for PPGL could prevent adverse pregnancy-related outcomes.

FUNDING

US National Institutes of Health.

Role of deteriorated bone quality in the development of osteoporosis in pheochromocytoma and paraganglioma

CONTEXT

Pheochromocytoma (PHEO) and paraganglioma (PGL) (PHEO and PGL: PPGLs), catecholamine-producing tumors, represent an emerging cause of secondary osteoporosis. However, despite decreased bone mineral density (BMD), vertebral fracture (VF) is not associated with BMD in PPGLs.

OBJECTIVE

To evaluate whether deteriorated bone quality is involved in the development of osteoporosis in PPGLs.

PARTICIPANTS

Trabecular bone score (TBS), used to assess trabecular bone quality, was examined in 56 patients with PPGLs and 52 with non-functional adrenal tumors (AT). Radiograph of the spine was carried out in 35 patients with PPGLs, and TBS was analyzed in 18 patients with PPGLs at follow-up.

MAIN OUTCOME MEASURE

TBS and BMD at the lumbar spine in patients with PPGLs with and without VF.

RESULTS

PPGLs had a lower TBS (n = 56, 1.338 [1.294-1.420]) than non-functional AT (n = 52, 1.394 [1.342-1.444]; p = 0.033). Among those with PPGLs, patients with VF (n = 14, 1.314 [1.289-1.346]) had a lower TBS than those without VF (n = 21, 1.383 [1.324-1.426]; p = 0.046), despite no significant difference in BMD at the lumbar spine between the two groups (p = 0.501). An optimal cut-off level of TBS for diagnosing VF in PPGLs was 1.323, and its area under the curve was 0.702. The severity of catecholamine excess and maximal size of tumor were associated with decreased TBS in PPGLs patients (p = 0.016 and p = 0.020, respectively). Surgical resection of PPGLs improved TBS at follow-up, with 2.5% increase (p = 0.007).

CONCLUSIONS

This study provides evidence for the importance of deteriorated bone quality rather than decreased bone mass in the development of VF in PPGLs.

Prognostic Nomograms for Predicting Overall Survival and Cancer-Specific Survival of Patients With Malignant Pheochromocytoma and Paraganglioma

BACKGROUND

Malignant pheochromocytoma and paraganglioma (PPGL) are rare tumors with few prognostic tools. This study aimed to construct nomograms for predicting 3- and 5-year survival for patients with malignant PPGL.

METHODS

The patient data was retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. A total of 764 patients diagnosed with malignant PPGL from 1975 to 2016 were included in this study. The patients were randomly divided into two cohorts; the training cohort (n = 536) and the validation cohort (n = 228). Univariate analysis, Lasso regression, and multivariate Cox analysis were used to identify independent prognostic factors, which were then utilized to construct survival nomograms. The nomograms were used to predict 3- and 5-year overall survival (OS) and cancer-specific survival (CSS) for patients with malignant PPGL. The prediction accuracy of the nomogram was assessed using the concordance index (C-index), receiver operating characteristic (ROC) curves and calibration curves. Decision curve analysis (DCAs) was used to evaluate the performance of survival models.

RESULTS

Age, gender, tumor type, tumor stage, or surgery were independent prognostic factors for OS in patients with malignant PPGL, while age, tumor stage, or surgery were independent prognostic factors for CSS (P <.05). Based on these factors, we successfully constructed the OS and CSS nomograms. The C-indexes were 0.747 and 0.742 for the OS and CSS nomograms, respectively. In addition, both the calibration curves and ROC curves for the model exhibited reliable performance.

CONCLUSION

We successfully constructed nomograms for predicting the OS and CSS of patients with malignant PPGL. The nomograms could inform personalized clinical management of the patients.

Characteristics and genetic testing outcomes of patients with clinically suspected paraganglioma/pheochromocytoma (PGL/PCC) syndrome in Singapore

BACKGROUND

Hereditary paraganglioma (PGL) and pheochromocytoma (PCC) syndromes are rare conditions, with limited data on spectrum of causative gene variants of these syndromes in Asian patients.

METHODS

We describe the clinical characteristics and genetic testing outcomes of patients with suspected hereditary PGL/PCC who were referred to a tertiary cancer genetics clinic in Singapore.

RESULTS

Among 2196 patients with suspected hereditary cancer syndrome evaluated at the cancer genetics clinic from 2000 to 2019, 13/2196 (0.6%) patients fulfilled clinical suspicion for hereditary PGL/PCC syndrome. After genetic counselling, 10 patients underwent multi-gene next generation sequencing and deletion/duplication analysis, including SDHAF2, SDHA, SDHB, SDHC, SDHD, VHL, NF1, RET, MAX, and TMEM127. Seven of 10 patients (70%) were identified to carry pathogenic variants, including 3 unrelated Chinese patients with head and neck PGL who carried the same SDHD: c.3G > C (p.Met1Ile) variant that was previously reported to be a possible founder variant in Chinese, and 3 patients with urogenital PGL and 1 patient with retroperitoneal PGL who carried different SDHB variants. Variant carriers were younger, more likely to present with multiple tumours, or have family history of paraganglioma or pheochromocytoma, than non- variant carriers.

CONCLUSION

Hereditary PGL/PCC accounts for only 0.6% of patients seen in an adult cancer genetics clinic in Asia. SDHD and SDHB genes remain the most important causative genes of hereditary PGL/PCC in Asia even when patients are tested with multi-gene NGS panel.

Pheochromocytoma and Paraganglioma: From Treatment to Follow-up

Pheochromocytomas (PCC) and paragangliomas (PGL) are rare neuroendocrine tumors arising from chromaffin cells in the adrenal medulla, sympathetic or parasympathetic ganglia. Currently, the only curative treatment option of pheochromocytomas/paraganglioma (PPGL) is surgical resection. Surgery aims to eliminate both risks of hypersecretion and tumor growth. The consequences of hypersecretion should be carefully controlled with medical therapy before and during the surgery. Postoperative major complications are hypotension and rebound hypoglycemia, and patients should be followed closely for 24-48 hours. The choice of surgical approach is determined based on multiple factors, including germline genetic test results, the size of the tumor, body mass index, surgeon's experience, and the likelihood of malignancy. Primary tumor resection does not completely eliminate the risk of tumor persistence and recurrence. Therefore, all patients with PPGL who are surgically treated should be followed for at least 10 years for recurrent disease and new tumor formation. Although surgical resection is the only curative treatment for PPGLs, surgical treatment is palliative except for resectable locoregional metastases in metastatic disease or for isolated distant metastases. The purpose of palliative treatment is to reduce hormone secretion and prevent metastasis-related complications in a critical anatomical location Combined and alfa;- and beta- adrenergic blockade is usually applied in patients with PPGL preoperatively. Some patients may present with pheochromocytoma multisystem crisis, which is a life-threatening condition that can involve cardiovascular, pulmonary, neurological, gastrointestinal, renal, hepatic and metabolic systems. Pheochromocytoma crisis may be spontaneous or may present with the tumor manipulation, trauma, corticosteroids, beta-blockers, anesthetic drugs, and the stimulation of non-adrenal surgical stress. These patients should be considered as medical emergencies rather than surgical emergencies. In this review, it was aimed to evaluate the pre-, per and post-operative management, curative and palliative surgical management, and postoperative outcomes and follow-up of the patients with PPGLs.

Perioperative management of pheocromocytoma/ paraganglioma: a comprehensive review

Pheochromocytomas are rare neuroendocrine neoplasms that require adequate preoperative evaluation in order to prevent and lessen the serious complications of catecholamine hypersecretion. Preoperative management contributes to reducing morbidity and mortality rates in patients who have not been diagnosed with this condition and undergo any surgery. However, current mortality seems to be lower, a fact attributed to preoperative management with alpha blockers.

Whole Exome Sequencing Identifies Novel Genetic Alterations in Patients with Pheochromocytoma/Paraganglioma

BACKGROUND

Pheochromocytoma and paragangliomas (PPGL) are known as tumors with the highest level of heritability, approximately 30% of all cases. Clinical practice guidelines of PPGL recommend genetic testing for germline variants in all patients. In this study, we used whole exome sequencing to identify novel causative variants associated with PPGL to improve the detection of rare genetic variants in our cohort.

METHODS

Thirty-six tested negative for pathogenic variants in previous Sanger sequencing or targeted gene panel testing for PPGL underwent whole exome sequencing. Whole exome sequencing was performed using DNA samples enriched using TruSeq Custom Enrichment Kit and sequenced with MiSeq (Illumina Inc.). Sequencing alignment and variant calling were performed using SAMtools.

RESULTS

Among previously mutation undetected 36 patients, two likely pathogenic variants and 13 variants of uncertain significance (VUS) were detected in 32 pheochromocytoma-related genes. SDHA c.778G>A (p.Gly260Arg) was detected in a patient with head and neck paraganglioma, and KIF1B c.2787-2A>C in a patient with a bladder paraganglioma. Additionally, a likely pathogenic variant in BRCA2, VUS in TP53, and VUS in NFU1 were detected.

CONCLUSION

Exome sequencing further identified genetic alterations by 5.6% in previously mutation undetected patients in PPGL. Implementation of targeted gene sequencing consisted of extended genes of PPGL in routine clinical screening can support the level of comprehensive patient assessment.

Catecholamine physiology and its implications in patients with COVID-19

The risk factors for severe COVID-19 are diverse, yet closely resemble the clinical manifestations of catecholamine excess states (eg, hypertension, cardiovascular disease, immune dysregulation, and hyperglycaemia), suggesting a potentially common basis for disease. Unfortunately, severe illness (eg, respiratory failure, compromised cardiac function, and shock) incurred by COVID-19 hinders the direct study of catecholamines in these patients, especially among those on multiple medications or those on adrenaline or noradrenaline infusions, or both. Phaeochromocytoma and paraganglioma (PPGL) are tumours that secrete catecholamines, namely adrenaline and noradrenaline, often in excess. PPGL are well studied disease processes in which the effects of catecholamines are easily discernible and therefore their potential biochemical and physiological influences in patients with COVID-19 can be explored. Because catecholamines are expected to have a role in patients with critical illness, patients on vasopressor infusions, and patients who sustain some acute and chronic physical stresses, the challenges involved in the management of catecholamine excess states are directly relevant to the treatment of patients with COVID-19. In this Personal View, we discuss the complex interplay between catecholamines and COVID-19, and the management of catecholamine excess states, while referencing relevant insights derived from the study of PPGL.

Molecular characterization of CNS paragangliomas identifies cauda equina paragangliomas as a distinct tumor entity

Paragangliomas/pheochromocytomas are rare neuroendocrine tumors that arise from the adrenal gland or ganglia at various sites throughout the body. They display a remarkable diversity of driver alterations and are associated with germline mutations in up to 40% of the cases. Comprehensive molecular profiling of abdomino-thoracic paragangliomas revealed four molecularly defined and clinically relevant subtypes. Paragangliomas of the cauda equina region are considered to belong to one of the defined molecular subtypes, but a systematic molecular analysis has not yet been performed. In this study, we analyzed genome-wide DNA methylation profiles of 57 cauda equina paragangliomas and show that these tumors are epigenetically distinct from non-spinal paragangliomas and other tumors. In contrast to paragangliomas of other sites, chromosomal imbalances are widely lacking in cauda equina paragangliomas. Furthermore, RNA and DNA exome sequencing revealed that frequent genetic alterations found in non-spinal paragangliomas—including the prognostically relevant SDH mutations—are absent in cauda equina paragangliomas. Histologically, cauda equina paragangliomas show frequently gangliocytic differentiation and strong immunoreactivity to pan-cytokeratin and cytokeratin 18, which is not common in paragangliomas of other sites. None of our cases had a familial paraganglioma syndrome. Tumors rarely recurred (9%) or presented with multiple lesions within the spinal compartment (7%), but did not metastasize outside the CNS. In summary, we show that cauda equina paragangliomas represent a distinct, sporadic tumor entity defined by a unique clinical and morpho-molecular profile.

Nonhypertensive male with multiple paragangliomas of the heart and neck: A case report

BACKGROUND

Paraganglioma is a rare disease that can be lethal if undiagnosed. Thus, quick recognition is very important. Cardiac paragangliomas are found in patients who have hypertension. The classic symptoms are the triad of headaches, palpitations, and profuse sweating. We describe a very rare case of multiple paragangliomas of the heart and bilateral carotid artery without hypertension and outline the management strategies for this disease.

CASE SUMMARY

A 46-year-old man presented with the chief complaint of recently recurrent chest pain with a history of hemangioma of the bilateral carotid artery that had been surgically removed. He was found to have an intracardiac mass in the right atrioventricular groove and underwent successful excision. The final pathology demonstrated that the intracardiac mass was a cardiac paraganglioma, and the patient had an increased level of normetanephrine in the blood. The pathology and immunohistochemistry results showed that the bilateral carotid masses were also paragangliomas. During the 3 mo follow-up period, the patient did not experience recurrence of chest pain.

CONCLUSION

To our knowledge, this is the first case of multiple paragangliomas of the heart and neck without hypertension. This rare disease can be lethal if left undiagnosed. Thus, quick recognition is very important. The key to the diagnosis of cardiac paraganglioma is the presence of typical symptoms, including headaches, palpitations, profuse sweating, hypertension, and chest pain. Radiology can demonstrate the intracardiac mass. It is important to determine the levels of normetanephrine in the blood. The detection of genetic mutations is also recommended. Surgical resection is necessary to treat the disease and obtain pathological evidence.

Paraganglioma in the posterior mediastinum: a case report

Background

Paragangliomas are tumors that arise from extra-adrenal chromaffin cells. Herein, we present a rare case of a functional paraganglioma in the posterior mediastinum.

Case presentation

A 36-year-old man presented with paroxysms of chest pain and headache. At presentation, the patient’s blood pressure was 190/120 mmHg. Chest computed tomography and magnetic resonance imaging revealed a left paravertebral mass in the posterior mediastinum. ¹²³I-metaiodobenzylguanidine scanning revealed focally high tracer uptake in the left paravertebral area. The metanephrine level in the urine was elevated, confirming a rare, catecholamine-producing, functional paraganglioma in the posterior mediastinum. Before surgery, the patient was prepared by orally administering α- and β-adrenergic blockers. The mass was then resected via a lateral thoracotomy. The metanephrine level in urine was normal 24 h after surgery.

Conclusions

Paragangliomas in the posterior mediastinum are very rare, but more than half of all cases are functional. The associated symptoms are curable with complete resection, and long-term follow-up for recurrence is important.

[Chronic pheochromocytoma-induced myocardial injuries: What should we expect from modern and classical echocardiographic tools?]

INTRODUCTION

Pheochromocytoma is a rare disease, which may manifest as severe cardiac complications. Apart from these situations, the "chronic" cardiac impact is not clearly defined. A cardiac MRI study suggests that these patients are carrying areas of fibrosis and foci of left ventricular myocarditis. Since these abnormalities are usually associated with altered left ventricular longitudinal systolic strain, we hypothesize that this strain is altered in patients with a "chronic" pheochromocytoma.

METHOD

This retrospective case-control study was performed using patients from the Bordeaux University Hospital database, included between 2008 and 2016. We compared the left ventricular global longitudinal strain (GLS), radial and circumferential systolic strain and classic echocardiographic parameters between patients with pheochromocytoma and controls matched for age, sex, body mass index and systolic blood pressure.

RESULTS

The analysis included 47 patients and 47 correctly matched controls. There were no statistically significant differences between the 2 groups in terms of GLS (-20.7±2.4% vs. -20.2±2.7%, P=0.40), radial strain, left ventricular mass or diastolic function. Left ventricular ejection fraction and circumferential strain were significantly higher in patients than in controls, with a significantly lower telediastolic diameter.

CONCLUSION

No significant changes in GLS were observed in our pheochromocytoma patients, compared with controls. Several hypotheses may explain these results. The presence of fibrosis foci and areas of left ventricular myocarditis being associated with a poor cardiological prognosis, a systematic cardiac MRI could be discussed in these patients, until further studies are performed.

Coexistence of osteoporosis and atherosclerosis in pheochromocytoma: new insights into its long-term management

Osteoporosis and atherosclerosis frequently coexist in patients with pheochromocytoma. The presence of osteoporosis may predict that of atherosclerosis and vice versa in patients with PHEO. These findings have implications for the long-term management of the pheochromocytoma and its potential chronic complications.

INTRODUCTION

Pheochromocytoma (PHEO), a catecholamine-producing tumor, is often found incidentally, and it may be present for years before it is diagnosed. However, long-term exposure to catecholamines excess may induce chronic complications, such as osteoporosis and atherosclerosis. We aimed to evaluate concomitant osteoporosis and atherosclerosis in patients with PHEO.

METHODS

Fifty-one patients with PHEO and 51 patients with a non-functional adrenal tumor were compared radiographically for the prevalence of vertebral fracture (VF), a typical osteoporotic fracture, and abdominal aortic calcification (AAC).

RESULTS

In patients with PHEO, the prevalence of AAC was higher in those with VF (58%) than in those without (6%, p < 0.001). AAC was associated with VF after adjusting for age and sex (odds ratio, 1.53; 95% confidence interval, 1.07-2.46; p = 0.003) in patients with PHEO. The degree of catecholamine excess correlated with the presence of VF and AAC (p = 0.007). The prevalence of VF was higher in patients with PHEO (37%) than those with non-functional AT (12%, p = 0.005), but the prevalence of AAC was comparable between the two groups (25% and 19%, p = 0.636). VF and AAC more frequently coexisted in patients with PHEO (22%) than in those with non-functional AT (2%, p = 0.003).

CONCLUSION

This study represents the first demonstration that osteoporosis and atherosclerosis frequently coexist in patients with PHEO. The presence of osteoporosis may predict that of atherosclerosis and vice versa in patients with PHEO. These findings have implications for the long-term management of the PHEO and its potential chronic complications.

A 3-min UPLC-MS/MS method for the simultaneous determination of plasma catecholamines and their metabolites: Method verification and diagnostic efficiency

OBJECTIVE

To verify a rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the quantification of catecholamines and their metabolites, and to validate its efficiency for the diagnosis of phaeochromocytomas and paragangliomas (PPGLs).

METHODS

Plasma samples were pretreated with solid-phase extraction, followed by a 3-min UPLC-MS/MS analysis to quantify epinephrine (E), norepinephrine (NE), dopamine (DA), metanephrine (MN), normetanephrine (NMN) and 3-methoxytyramine (3-MT), simultaneously. The UPLC-MS/MS method was comprehensively verified and its diagnostic efficiency on PPGLs was tested using 7 PPGLs and 408 non-PPGLs patient plasma samples.

RESULTS

Using the developed method, the limit of detections (LODs) of the 6 analytes ranged from 0.0002 nmol/L (MN) to 0.0250 nmol/L (NE), while the lower limit of measuring intervals (LLMIs) ranged from 0.05 nmol/L (E, MN and NMN) to 0.10 nmol/L (NE and DA). The reportable ranges were 0.05-30.00 nmol/L for E, MN and NMN, 0.10-30.00 nmol/L for NE and DA, 1.00-300.00 pg/mL for 3-MT. No significant matrix effect was detected after correcting using internal standard. Besides, intra-day and inter-day precision were also within acceptance criteria with coefficient of variations (CVs) ≤ 15% and recoveries ranged from 95% to 115% for all the 6 analytes. The carryover effect was lower than 10%. Its diagnostic efficiency for PPGLs was significantly increased, the areas under the receiver operating characteristic (ROC) curves were increased from 68.7% to 89.1% (using E, NE and DA) to 75.2%-99.9% (using MN, NMN and 3-MT).

CONCLUSION

This study verified a rapid UPLC-MS/MS method for the determination of catecholamines and their metabolites in human plasma. It showed high diagnostic efficiency and will serve as an important tool to avoid the risk for missing patients with PPGLs.

Endocrine Causes of Hypertension

PURPOSE OF REVIEW

To discuss selected endocrine causes of hypertension and to provide practical clinical recommendations regarding the evaluation and treatment of these disorders.

RECENT FINDINGS

More than 15 endocrine disorders with varying rates of prevalence can cause hypertension. For example, primary aldosteronism may exist in up to 20% of patients with resistant hypertension. Recognition of these important secondary causes of hypertension is essential to provide contemporary targeted therapies in order to improve long-term disease outcomes. Clinicians must have a broad understanding of the prevalence, clinical presentation, and current diagnostic modalities for endocrine causes of hypertension to facilitate prompt referral, identification, and optimal management of these disorders. Endocrine causes of hypertension are multifactorial and, in some cases, widely prevalent. It is important for clinicians considering secondary causes of hypertension to be knowledgeable about the underlying pathophysiology of these disorders and to understand when additional evaluation and treatment may be needed.

Effects of Repeated 131I-Meta-Iodobenzylguanidine Radiotherapy on Tumor Size and Tumor Metabolic Activity in Patients with Metastatic Neuroendocrine Tumors

¹³¹I-meta-iodobenzylguanidine (¹³¹I-MIBG) radiotherapy has shown some survival benefits in metastatic neuroendocrine tumors (NETs). European Association of Nuclear Medicine clinical guidelines for ¹³¹I-MIBG radiotherapy suggest a repeated treatment protocol, although none currently exists. The existing single-high-dose ¹³¹I-MIBG radiotherapy (444 MBq/kg) has been shown to have some benefits for patients with metastatic NETs. However, this protocol increases adverse effects and requires alternative therapeutic approaches. Therefore, the aim of this study was to evaluate the effects of repeated ¹³¹I-MIBG therapy on tumor size and tumor metabolic response in patients with metastatic NETs. Methods: Eleven patients with metastatic NETs (aged 49.2 ± 16.3 y) prospectively received repeated 5,550-MBq doses of ¹³¹I-MIBG therapy at 6-mo intervals. In total, 31 treatments were performed. The mean number of treatments was 2.8 ± 0.4, and the cumulative ¹³¹I-MIBG dose was 15,640.9 ± 2,245.1 MBq (286.01 MBq/kg). Tumor response was observed by CT and ¹⁸F-FDG PET or by ¹⁸F-FDG PET/CT before and 3-6 mo after the final ¹³¹I-MIBG treatment. Results: On the basis of the CT findings with RECIST, 3 patients showed a partial response and 6 patients showed stable disease. The remaining 2 patients showed progressive disease. Although there were 2 progressive-disease patients, analysis of all patients showed no increase in summed length diameter (median, 228.7 mm [interquartile range (IQR), 37.0-336.0 mm] to 171.0 mm [IQR, 38.0-270.0 mm]; P = 0.563). In tumor region-based analysis with partial-response and stable-disease patients (n = 9), ¹³¹I-MIBG therapy significantly reduced tumor diameter (79 lesions; median, 16 mm [IQR, 12-22 mm] to 11 mm [IQR, 6-16 mm]; P < 0.001). Among 5 patients with hypertension, there was a strong trend toward systolic blood pressure reduction (P = 0.058), and diastolic blood pressure was significantly reduced (P = 0.006). Conclusion: Eighty-two percent of metastatic NET patients effectively achieved inhibition of disease progression, with reduced tumor size and reduced metabolic activity, through repeated ¹³¹I-MIBG therapy. Therefore, this relatively short-term repeated ¹³¹I-MIBG treatment may have potential as one option in the therapeutic protocol for metastatic NETs. Larger prospective studies with control groups are warranted.

Somatic SDHA mutations in paragangliomas in siblings: Case report of 2 cases

RATIONALE

Paragangliomas (PGLs) are rare neuroendocrine tumors that are strongly influenced by genetics, and succinate dehydrogenase-deficient PGLs appear to constitute one of the most important categories. Interestingly, somatic PGLs only possess genomic alterations involving the SDHB and SDHD subunits, and no SDHA alterations have been described. Here, we are presenting the clinical and genetic analyses of 2 cases with the first somatic SDHA variant identified in PGLs.

PATIENT CONCERNS

Here, we reported 2 family members with the diagnosis of PGL. Patient 1 is a 55-year-old woman with a functionally perigastric PGL that co-occurred with a gastric gastrointestinal stromal tumor (GIST), and patient 2 is a 43-year-old woman with a nonfunctionally pericardial PGL, who was the younger sister of the first patient.

DIAGNOSES

Imaging surveys of the 2 cases depicted the presence of a perigastric and a pericardial mass, respectively. A diagnosis of paragangliomas was established by immunohistochemistry (IHC).

INTERVENTIONS

Both patients underwent single-stage resection of the lesion after preoperative oral α-adrenoceptor therapy for 2 weeks. We later performed comprehensive genomic profiling on the tumor samples, including PGL and GIST from patient 1 and PGL from patient 2, and searched for novel actionable mutations, including in all succinate dehydrogenase subunits, as the IHC results were negative for SDHB.

OUTCOMES

Both patients had an uneventful recovery after surgery and the sequencing showed a novel somatic variant in the SDHA gene on chromosome 5q11 (c.1945_1946delTT). Regular follow-up with biochemical testing and image studies showed no evidence of recurrence after a year for patient 1 and 6 years for patient 2.

LESSONS

PGLs often lead to considerable diagnostic difficulty due to their multiple anatomical locations and variable symptoms, as presented by our cases. The comprehensive use of images and plasma/urine catecholamine measurement can aid the diagnosis of PGLs. In addition, our findings also demonstrate the usefulness and importance of genetic analysis of SDHA mutations in patients exhibiting SDHB IHC-negative PGL. Additional studies utilizing comprehensive genomic profiling are needed to identify the group of PGLs harboring this SDHA genomic alteration.

Pheochromocytoma Metastasing to the Jaw: Review of the Literature and New Case

Pleochromocytoma is a benign neuroectodermal tumor of the adrenal medulla. Ten to thirty percent of these tumors become metastatic. The bone is the most frequent site for metastasis but jaw involvement is reported rarely. A case of mandibular involvement is reported and a literature review in this topic is presented. Preoperative management of these patients undergoing general anesthesia is not a routine practice in maxillofacial surgery, so this topic is also is explained.

Management of primary cardiac paraganglioma

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.

Genetic predisposition to neural crest-derived tumors: revisiting the role of KIF1B

OBJECTIVE

We previously described a family in which predisposition to pheochromocytoma (PCC) segregates with a germline heterozygous KIF1B nucleotide variant (c.4442G>A, p.Ser1481Asn) in three generations. During the clinical follow-up, one proband's brother, negative for the KIF1B nucleotide variant, developed a bilateral PCC at 31 years. This prompted us to reconsider the genetic analysis.

DESIGN AND METHODS

Germline DNA was analyzed by next-generation sequencing (NGS) using a multi-gene panel plus MLPA or by whole exome sequencing (WES). Tumor-derived DNA was analyzed by SnapShot, Sanger sequencing or NGS to identify loss-of-heterozygosity (LOH) or additional somatic mutations.

RESULTS

A germline heterozygous variant of unknown significance in MAX (c.145T>C, p.Ser49Pro) was identified in the proband's brother. Loss of the wild-type MAX allele occurred in his PCCs thus demonstrating that this variant was responsible for the bilateral PCC in this patient. The proband and her affected grandfather also carried the MAX variant but no second hit could be found at the somatic level. No other pathogenic mutations were detected in 36 genes predisposing to familial PCC/PGL or familial cancers by WES of the proband germline. Germline variants detected in other genes, TFAP2E and TMEM214, may contribute to the multiple tumors of the proband.

CONCLUSION

In this family, the heritability of PCC is linked to the MAX germline variant and not to the KIF1B germline variant which, however, may have contributed to the occurrence of neuroblastoma (NB) in the proband.

Molecular genetics of human hypertension

PURPOSE OF REVIEW

Genetic variance on blood pressure was shown about 100 years ago; a Mendelian inheritance was initially presumed. Platt and Pickering conducted a lively debate, whether blood pressure was inherited in a Mendelian fashion or whether the condition was polygenic. Genetic-hypertension research has appropriately followed both pathways.

RECENT FINDINGS

Genome-wide association studies, Pickering model, have identified more than 500 blood-pressure loci, the targets of which are waiting to be evaluated. Then, come the 'dark-horses' of hypertension, namely 'secondary' causes. These conditions have been remarkably elucidative including pheochromocytoma, primary aldosteronism, Cushing's syndrome, and even renovascular hypertension. All these conditions feature genetic causes. Finally, arrive the Platt followers. A plethora of Mendelian conditions located within the kidney are established. These syndromes involve increased sodium (as chloride) absorption in the distal nephron. Finally, nonsalt-dependent Mendelian forms involving the vascular directly have been described. Mechanistically, Mendelian forms have large effects on blood pressure and offer effective treatment targets.

SUMMARY

Which genetic models will bring us improved therapies? Ongoing studies will answer that question. It behooves the clinician to follow this dynamic area of research.

Pheochromocytoma and Paraganglioma: From Clinical Findings to Diagnosis

The majority of pheochromocytoma (PCC) and paraganglioma (PGL) are endocrine active tumors, and they cause clinical symptoms by secreting excess one or more catecholamines (epinephrine, norepinephrine, and dopamine) and their inactive metabolites (metanephrine, normetanephrine, 3-metoxythromine). Although signs and symptoms regarding excess catecholamine often develop in PCC and PGL (PPGL), non-functional PPGLs may present with local compression symptoms. Persistent, sometimes worsening hypertension is the most common finding and occurs in 80-90% of the patients. Classically defined symptom triad; headache, sweating and palpitations are seen in only 25% of the patients with PCC. The difference of clinical symptoms may be related to the tumor secretion, epinephrine or norepinephrine. All patients with signs and symptoms suggestive of catecholamine excess should be screened by biochemical tests regardless of whether they have hypertension or not. Not all patients with newly diagnosed hypertension need to be screened, but only patients with additional tips for catecholamine excess should be screened. Approximately 20% of the PPGLs are diagnosed in childhood, and the male/female ratio is 2/1. 60-90% of pediatric patients present with hypertension. PPGL in pregnancy is rare, and the estimated incidence ranges between 1/15000-1/54000. Although early diagnosis is the most important factor in preventing mortality, diagnosis is not as easy as it is a rare condition. Hypertension is a common complication in pregnancy, occurring in 5-10%. Computed tomography should not be used as the imaging method during pregnancy; the first choice is magnetic resonance imaging with gadolinium or without contrast. Plasma free metanephrine or 24-hour urinary fractionated metanephrine level is recommended as a screening test for the diagnosis of PPGL in the Endocrine Society Clinical Practice Guideline. In suspicious situations, tests should be repeated. Since 40% of these patients have germline mutations, genetic tests are recommended for all patients with PPGL regardless of family history and age. Preoperative knowledge of germline mutations affects the surgical approach and the extent of adrenalectomy. After the biochemical diagnosis is made in PPGL, the tumor is localized with imaging methods to make the operation plan. In this review, we aimed to evaluate the clinical findings, diagnostic tests, and imaging studies for tumor localization in PPGL.

Special Article - The management of resistant hypertension: A 2020 update

Resistant hypertension (RH) induces higher morbidity and mortality due to cardiovascular disease and stroke than hypertension without treatment resistance. New guidelines define RH as blood pressure (BP) ≥130/80 mmHg in a patient taking ≥3 antihypertensive agents of different classes or BP <130/80 mmHg in a patient taking ≥4 antihypertensive drugs. According to the new definition, pseudo-resistance due to error in BP measurement, white coat effect and medication nonadherence must be excluded to make the diagnosis of RH. This 2020 update focuses on the lifestyle and antihypertensive drug management of RH and includes recent proof-of-principle trials of renal nerve ablation in hypertension. Stepwise evidence-based pharmacologic treatment of RH includes optimization of the 3-drug regimen, substitution of a thiazide-like for a thiazide diuretic and addition of a mineralocorticoid receptor antagonist as the fourth drug. Non-evidence-based recommendations include addition of a β-blocker as the fifth drug and switching to a minoxidil-based regimen as the final step in achieving BP control.

Cardiovascular Manifestations and Complications of Pheochromocytomas and Paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) are rare neuro-endocrine tumors. The catecholamine surge causes paroxysmal or chronic secondary hypertension. PPGLs may present as hypertensive- or PPGL-crisis with severe life-threatening cardiac and cerebrovascular complications. PPGLs-induced cardiac manifestations have been reported with diagnoses as PPGLs-induced electrocardiogram (ECG) changes “mimicking acute myocardial infarction”, arrhythmias, myocarditis, acute coronary syndrome, dilated cardiomyopathy, and lately as takotsubo syndrome. Critical analysis of these reports reveals that most of these cardiac manifestations have certain features in common. They have a dramatic clinical presentation and are reversible if the disease is treated with appropriate medical therapy and surgical resection of the PPGL tumor. They may have the same repolarization ECG changes irrespective of the clinical cardiac diagnosis, usually associated with mild to moderate elevations of myocardial biomarkers as troponins and normal coronary arteries. The histopathological findings are usually focal or multifocal in the form hypercontracted sarcomeres and contraction band necrosis (myofibrillar degeneration) with subsequent secondary mononuclear cell infiltration. Evidences argue the PPGL caused surge of catecholamines triggers hyperactivation of the sympathetic nervous system with cardiac sympathetic nerve terminal disruption with norepinephrine spillover causing the cardiac complications. A comprehensive review of various reported cardiovascular manifestations and complications of PPGLs are presented.

Prevention and Management of Hormonal Crisis during Theragnosis with LU-DOTA-TATE in Neuroendocrine Tumors. A Systematic Review and Approach Proposal

Neuroendocrine tumors (NETs) frequently overexpress somatostatin receptors (SSTR) on their cell surface. The first-line pharmacological treatment for inoperable metastatic functioning well-differentiated NETs are somatostatin analogs. On second line, Lu-DOTA-TATE (177Lu-DOTA0 Tyr 3 octreotate) has shown stabilization of the disease and an increase in progression free survival, as well as effectiveness in controlling symptoms and increasing quality of life. The management of functional NETs before and during LU-DOTA-TATE treatment is specially challenging, as several complications such as severe carcinoid and catecholamine crisis have been described. The aim of this review is to establish practical guidance for the management and prevention of the most common hormonal crises during radionuclide treatment with Lu-DOTA-TATE: carcinoid syndrome (CS) and catecholamine hypersecretion, as well as to provide a brief commentary on other infrequent metabolic complications. To establish a practical approach, a systematic review was performed. This systematic review was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and conducted using MEDLINE (accessed from PubMed), Google Scholar and ClinicalTrials.gov. Literature searches found 449 citations, and finally nine were considered for this systematic review.

Hormones Secretion and Rho GTPases in Neuroendocrine Tumors

Neuroendocrine tumors (NETs) belong to a heterogeneous group of neoplasms arising from hormone secreting cells. These tumors are often associated with a dysfunction of their secretory activity. Neuroendocrine secretion occurs through calcium-regulated exocytosis, a process that is tightly controlled by Rho GTPases family members. In this review, we compiled the numerous mutations and modification of expression levels of Rho GTPases or their regulators (Rho guanine nucleotide-exchange factors and Rho GTPase-activating proteins) that have been identified in NETs. We discussed how they might regulate neuroendocrine secretion.

Genetic screening for monogenic hypertension in hypertensive individuals in a clinical setting

BACKGROUND

Monogenic hypertension describe a series of hypertensive syndromes that are inherited by Mendelian laws. Sometimes genetic testing is required to provide evidence for their diagnoses, precise classification and targeted treatment. This study is the first to investigate the clinical utility of a causative gene screening and the combined yield of gene product expression analyses in cases with suspected monogenic hypertension.

METHODS

We performed a large-scale multi-centre clinical genetic research of 1179 expertly selected hypertensive individuals from the Chinese Han population. Targeted sequencing were performed to evaluate 37 causative genes of potential cases of monogenic hypertension. Pathogenic and likely pathogenic variants were classified using the American College of Medical Genetics guidelines. Additionally, 49 variants of unknown significance (VUS) that had relatively high pathogenicity were selected and analysed using immunoblot protein expression assays.

RESULTS

21 pathogenic or likely pathogenic variants were identified in 33 of 1179 cases (2.80%). Gene product expression analyses showed 27 VUSs harboured by 49 individuals (4.16%) could lead to abnormally expressed protein levels. Consequently, combining genetic screening with gene product expression analyses increased the diagnostic yield from 2.80% to 6.79%. The main aetiologies established were primary aldosteronism (PA; 27, 2.29%) and pheochromocytoma and paraganglioma (PPGL; 10, 0.85%).

CONCLUSION

Molecular diagnoses obtained using causative gene screening combined with gene product expression analyses initially achieved a modest diagnostic yield. Our data highlight the predominant roles of PA and PPGL. Furthermore, we provide evidence indicating the enhanced diagnostic ability of combined genetic and functional evaluation.

Von Hippel-Lindau Disease: Current Challenges and Future Prospects

Understanding of molecular mechanisms of tumor growth has an increasing impact on the development of diagnostics and targeted therapy of human neoplasia. In this review, we summarize the current knowledge on molecular mechanisms and their clinical implications in von Hippel-Lindau (VHL) disease. This autosomal dominant tumor syndrome usually manifests in young adulthood and predisposes affected patients to the development of benign and malignant tumors of different organ systems mainly including the nervous system and internal organs. A consequent screening and timely preventive treatment of lesions are crucial for patients affected by VHL disease. Surgical indications and treatment have been evaluated and optimized over many years. In the last decade, pharmacological therapies have been evolving, but are largely still at an experimental stage. Effective pharmacological therapy as well as detection of biomarkers is based on the understanding of the molecular basis of disease. The molecular basis of von Hippel-Lindau disease is the loss of function of the VHL protein and subsequent accumulation of hypoxia-inducible factor with downstream effects on cellular metabolism and differentiation. Organs affected by VHL disease may develop frank tumors. More characteristically, however, they reveal multiple separate microscopic foci of neoplastic cell proliferation. The exact mechanisms of tumorigenesis in VHL disease are, however, still not entirely understood and knowledge on biomarkers and targeted therapy is scarce.

The Changing Paradigm of Head and Neck Paragangliomas: What Every Otolaryngologist Needs to Know

BACKGROUND

Recommendations regarding head and neck paragangliomas (HNPGL) have undergone a fundamental reorientation in the last decade as a result of increased understanding of the genetic and pathophysiologic basis of these disorders.

OBJECTIVE

We aim to provide an overview of HNPGL and recent discoveries regarding their molecular genetics, along with updated recommendations on workup, treatment, and surveillance, and their implications for otolaryngologists treating patients with these disorders.

RESULTS

SDHx susceptibility gene mutations, encoding subunits of the enzyme succinate dehydrogenase (SDH), give rise to the Hereditary Pheochromocytoma/Paraganglioma Syndromes. SDHA, SDHB, SDHC, SDHD, and SDHAF2 mutations each result in unique phenotypes with distinct penetrance and risk for variable tumor development as well as metastasis. Genetic and biochemical testing is recommended for every patient with HNPGL. Multifocal disease should be managed in multi-disciplinary fashion. Patients with SDHx mutations require frequent biochemical screening and whole-body imaging, as well as lifelong follow-up with an expert in hereditary pheochromocytoma and paraganglioma syndromes.

CONCLUSION

Otolaryngologists are likely to encounter patients with HNPGL. Keeping abreast of the latest recommendations, especially regarding genetic testing, workup for additional tumors, multi-disciplinary approach to care, and need for lifelong surveillance, will help otolaryngologists appropriately care for these patients.

Pediatric applications of Dotatate: early diagnostic and therapeutic experience

In recent years, new somatostatin receptor agents (SSTRs) have become available for diagnostic imaging and therapy in neuroendocrine tumors. The novel SSTR ligand DOTA-DPhel-Tyr3-octreotate (Dotatate) in particular can be linked with ⁶⁸Gallium for diagnostic imaging purposes, and with the β-emitter ¹⁷⁷Lutetium for radiotherapy in the setting of neuroendocrine tumors. Dotatate imaging offers distinct advantages in the evaluation of neuroendocrine tumors compared to standard techniques, including greater target-to-background ratio and lesion conspicuity, high sensitivity/specificity, improved spatial resolution with positron emission tomography (PET)/CT or PET/MR, and decreased radiation exposure. Although currently off-label in pediatrics, Dotatate theranostics in children are being explored, most notably in the setting of neuroblastoma and hereditary neuroendocrine syndromes. This article provides a multicenter case series of Dotatate imaging and therapy in pediatric patients in order to highlight the spectrum of potential clinical applications.

Molecular imaging of norepinephrine transporter-expressing tumors: current status and future prospects

The human norepinephrine transporter (hNET) is a transmembrane protein responsible for reuptake of norepinephrine in presynaptic sympathetic nerve terminals and adrenal chromaffin cells. Neural crest tumors, such as neuroblastoma, paraganglioma and pheochromocytoma often show high hNET expression. Molecular imaging of these tumors can be done using radiolabeled norepinephrine analogs that target hNET. Currently, the most commonly used radiopharmaceutical for hNET imaging is meta-[123I]iodobenzylguanidine ([123I]MIBG) and this has been the case since its development several decades ago. The γ-emitter, iodine-123 only allows for planar scintigraphy and single photon emission computed tomography imaging. These modalities typically have a poorer spatial resolution and lower sensitivity than positron emission tomography (PET). Additional practical disadvantages include the fact that a two-day imaging protocol is required and the need for thyroid blockade. Therefore, several PET alternatives for hNET imaging are actively being explored. This review gives an in-depth overview of the current status and recent developments in clinical trials leading to the next generation of clinical PET ligands for imaging of hNET-expressing tumors.

Data set for the reporting of pheochromocytoma and paraganglioma: explanations and recommendations of the guidelines from the International Collaboration on Cancer Reporting

BACKGROUND AND OBJECTIVES

The International Collaboration on Cancer Reporting (ICCR) is a not-for-profit to develop evidence-based, internationally agreed-upon standardized data sets for each anatomic site, to be used throughout the world. Providing global standardization of pathology tumor classification, staging, and other reporting elements will lead to improved patient management and enhanced epidemiological research.

METHODS

Pheochromocytoma and paraganglioma are uncommon and are frequently overlooked in registry data sets. Malignant criteria have previously been defined only when there was metastatic disease.

RESULTS

With recent recognition of a significant inheritance association and the development of risk stratification tools, this data set was created in order to obtain more meaningful outcomes and management data, using similar criteria across the global pathology community. Issues related to key core and non-core elements, especially clinical hormonal status, familial history, tumor focality, proliferative fraction, adverse or risk stratification features, and ancillary techniques, are discussed in the context of daily application to these types of specimens.

CONCLUSIONS

The ICCR data set, developed by an international panel of endocrine organ specialists, establishes a pathology-standardized reporting guide for pheochromocytoma and paraganglioma.