Pheochromocytoma and Paraganglioma: From Epidemiology to Clinical Findings

Pheochromocytoma in a patient with heterotaxy syndrome: a case report

BACKGROUND

Heterotaxy syndrome is a rare congenital condition characterized by abnormal arrangement of thoracoabdominal organs, often associated with complex cardiac and splenic anomalies. Pheochromocytoma is a rare neuroendocrine tumor that overproduces catecholamines, leading to various complications. The co-occurrence of heterotaxy syndrome and pheochromocytoma has not been previously reported. This case report presents a unique finding of pheochromocytoma in a patient with heterotaxy syndrome and a functioning ectopic spleen, offering novel clinical insights.

CASE PRESENTATION

A 19-year-old male with congenital heart disease was incidentally found to have a right adrenal mass during abdominal ultrasonography which followed abnormal lab results. Computed tomography (CT) scans confirmed abnormal organ positioning consistent with heterotaxy syndrome, including a midline liver, right-sided colon, and the absence of a spleen in its typical location. Subsequent scintigraphy with Technetium-99 m denatured red blood cells revealed a functioning ectopic spleen in the left subdiaphragmatic space. The right adrenal mass was confirmed to be pheochromocytoma based on elevated urinary catecholamine levels. Despite recommendations for surgery, the patient chose medical management with alpha-blockers and remained stable over a one-year follow-up with no significant events.

CONCLUSIONS

This case is notable concurrency of pheochromocytoma and heterotaxy and for the rare occurrence of a functioning ectopic spleen in a patient with heterotaxy syndrome, a condition where splenic anomalies typically manifest as asplenia or polysplenia. The importance of extensive imaging, particularly Tc-99 m labeled denatured erythrocyte scintigraphy imaging, is emphasized, as routine imaging like CT scans may fail to detect ectopic organs. Additionally, the concurrent presence of pheochromocytoma (PCC) and heterotaxy syndrome, although rare, raises intriguing questions about their potential link. While this case does not explore the association in detail, chronic hypoxia caused by congenital cardiovascular anomalies in heterotaxy syndrome could activate hypoxia-inducible factors (HIFs), which may promote tumorigenesis, including the development of PCC. Future studies are warranted to explore these mechanisms further and clarify the pathophysiological connection between heterotaxy syndrome, hypoxia, and PCC.

Multifocal Paraganglioma Including the Cervical Sympathetic Chain

Multifocal head and neck paragangliomas are exceptionally rare. We present a patient with 4 synchronous tumors including a sympathetic chain lesion. This is a case report and literature review conducted from September 2021 to the present. Our 69-year-old male patient presented to the clinic with multifocal paraganglioma involving the right carotid body, right cervical sympathetic trunk, right glomus jugulare, and left glomus tympanicum. After preoperative embolization, successful surgical resection was performed for the right sympathetic trunk and right carotid body tumor. Postoperatively, the patient had a right Horner's syndrome but a strong voice and intact recurrent laryngeal nerve function. He also had first-bite syndrome and right cranial nerve XII weakness which resolved. Of interest, patient also has a strong family history of paragangliomas: his sister has malignant paragangliomas with lymph node involvement and his mother and nephew have non-malignant paragangliomas. To our knowledge, multifocal tumors including synchronous carotid body, sympathetic chain, glomus jugulare, and glomus tympanicum lesions occurring in 1 person have not been reported until now. As a result of this study, there is new light shed on the treatment and evaluation of patients who present with multifocal paraganglioma involving the sympathetic chain.

The role of cell cycle-related genes in the tumorigenesis of adrenal and thyroid neuroendocrine tumors

The molecular mechanisms underlying adrenal and thyroid neuroendocrine tumors, including their tumorigenesis, progression, and metastasis, involve unique pathways regulating cell cycle progression. To better understand these mechanisms and pathways, extensive in-depth research on cell cycle-related genes is necessary. This review aims to describe and interpret current single-cell RNA sequencing studies on neuroblastoma, medullary thyroid cancer, and pheochromocytoma tumors. Our review summarizes differentially expressed cell cycle-related genes with distinct functions, highlighting their potential as therapeutic targets and components of panels used to determine tumor type or aggressiveness. Although some insights have been gained, there is still limited information on these topics, and further research is required to explore the regulatory mechanisms of these tumors.

Surgical Management of Acute Appendicitis in a Patient with Diagnosed but "Unprepared" Pheochromocytoma: A Case Report

Pheochromocytoma is a rare tumor originating from the adrenal gland, characterized by the secretion of catecholamines. Due to the risk of hypertensive crises associated with catecholamine release, surgical procedures in pheochromocytoma patients are risky. In this case report, laparoscopic appendectomy for acute appendicitis in a patient who has pheochromocytoma will be presented. A 49-year-old female patient presented with abdominal pain. Physical examination showed guarding and rebound in the right lower quadrant. The patient, who had leukocytosis in the investigations, showed signs of acute appendicitis and a 5 cm right adrenal mass on the abdominal computed tomography. A previous abdominal magnetic resonance imaging by the endocrinology department six months ago revealed a 39x32 mm mass in the right adrenal gland and elevated urinary catecholamine levels. It was learned that the patient had not attended follow-up appointments during this period. The patient was consulted by endocrinology and an emergency laparoscopic appendectomy was performed. The patient, discharged on the 2nd day after surgery, did not experience any complications. The patient was referred to endocrinology, and preoperative preparations for pheochromocytoma surgery were initiated. In cases of emergency in patients diagnosed with pheochromocytoma emergency surgery can be performed with appropriate preoperative preparation.

L, Heredia-Espín M, Arias-Intriago M, Izquierdo-Condoy JS. Pheochromocytoma: an updated scoping review from clinical presentation to management and treatment

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors derived from chromaffin cells, with 80-85% originating in the adrenal medulla and 15-20% from extra-adrenal chromaffin tissues (paragangliomas). Approximately 30-40% of PPGLs have a hereditary component, making them one of the most genetically predisposed tumor types. Recent advances in genetic research have classified PPGLs into three molecular clusters: pseudohypoxia-related, kinase-signaling, and WNT-signaling pathway variants. Specifically, the detection of SDHB-related tumors indicates an increased risk of metastatic disease, which may impact decisions regarding functional imaging in patients with high suspicion of metastasis and influence targeted treatment strategies. Diagnosis of PPGLs primarily relies on biochemical testing, measuring catecholamines or their metabolites in plasma or urine. However, molecular testing, functional imaging, and targeted therapies have greatly enhanced diagnostic precision and management. Personalized treatment approaches based on genetic profiling are becoming integral to the clinical management of these tumors. In South American countries like Colombia, functional imaging techniques such as positron emission tomography/computed tomography (PET/CT) with tracers like 18F-DOPA, 18F-fluorodeoxyglucose (18F-FDG), and 68Ga-DOTA-conjugated somatostatin receptor-targeting peptides (68Ga-DOTA-SST) are used to guide follow-up and treatment strategies. Radionuclide therapy with lutetium-177 DOTATATE is employed for patients showing uptake in 68Ga-DOTA-SST PET/CT scans, while access to 131-MIBG therapy remains limited due to high costs and availability. Recent clinical trials have shown promise for systemic therapies such as sunitinib and cabozantinib, offering potential new options for patients with slow or moderate progression of PPGLs. These advancements underscore the potential of personalized and targeted therapies to improve outcomes in this challenging patient population.

Perioperative Blood Pressure Management Recommendations in Pediatric Pheochromocytoma: A 10-Year Narrative Review

BACKGROUND

Pheochromocytomas and paragangliomas are rare chromaffin cell-derived tumors characterized by catecholamine-secreting activity. Pheochromocytomas account for 1.7% of pediatric hypertension cases. Surgical resection, the definitive pheochromocytoma treatment, carries risks of hemodynamic instability and cardiovascular complications. Nevertheless, mortality rates decreased significantly in the latter half of the 20th century due to effective perioperative blood pressure (BP) management. The literature on BP management tailored to pediatric pheochromocytoma is limited, while the sustained hypertension rate in this population is high (up to 90%) and related to a high risk of intraoperative complications. In this narrative review, we provide up-to-date recommendations regarding BP management to minimize perioperative comorbidities in children with pheochromocytoma.

SUMMARY

Antihypertensive agents, primarily alpha (α)-blockers, should be promptly administered for suspected pheochromocytoma. Beta (β)-blockers may be introduced thereafter to counteract reflex tachycardia. The patient must be salt- and water-replete preoperation. Intraoperatively, stable hemodynamics should be ensured during anesthesia and surgery, and short-acting intravenous medications and resuscitation fluid should be supplied. Postoperatively, patients should be admitted to the pediatric intensive care unit for close monitoring for at least 24-48 h. Genetic testing is recommended for all pheochromocytoma patients. Identifying underlying mutations, like in succinate dehydrogenase subunit B, which is linked to a higher risk of multifocality and metastasis, is imperative for tailoring treatment strategies and prognostication.

KEY MESSAGES

Achieving optimal outcomes in pediatric pheochromocytoma relies on preoperative BP optimization with appropriate antihypertensive agents, intraoperative hemodynamic stability, and postoperative routine long-term follow-up to monitor for complications, recurrence, and metastasis. Future research should prioritize well-designed prospective multicenter studies with adequate sample sizes and, where feasible, randomized controlled trials with standardized protocols and appropriate endpoints. These studies should focus on the efficacy and safety of preoperative nonselective versus selective α-blockers, whether as monotherapy or combined with other medications (e.g., calcium channel blockers and/or β-blockers), or treatment without preoperative anti-hypertensives.

Using parenclitic networks on phaeochromocytoma and paraganglioma tumours provides novel insights on global DNA methylation

Despite the prevalence of sequencing data in biomedical research, the methylome remains underrepresented. Given the importance of DNA methylation in gene regulation and disease, it is crucial to address the need for reliable differential methylation methods. This work presents a novel, transferable approach for extracting information from DNA methylation data. Our agnostic, graph-based pipeline overcomes the limitations of commonly used differential methylation techniques and addresses the "small n, big k" problem. Pheochromocytoma and Paraganglioma (PPGL) tumours with known genetic aetiologies experience extreme hypermethylation genome wide. To highlight the effectiveness of our method in candidate discovery, we present the first phenotypic classifier of PPGLs based on DNA methylation achieving 0.7 ROC-AUC. Each sample is represented by an optimised parenclitic network, a graph representing the deviation of the sample's DNA methylation from the expected non-aggressive patterns. By extracting meaningful topological features, the dimensionality and, hence, the risk of overfitting is reduced, and the samples can be classified effectively. By using an explainable classification method, in this case logistic regression, the key CG loci influencing the decision can be identified. Our work provides insights into the molecular signature of aggressive PPGLs and we propose candidates for further research. Our optimised parenclitic network implementation improves the potential utility of DNA methylation data and offers an effective and complete pipeline for studying such datasets.

Case Report: Unveiling an anomalous diaphragmatic paraganglioma mimicking a hepatic tumor

Paragangliomas are rare neuroendocrine tumors, often associated with catecholamine secretion. These tumors can arise in various locations, with the majority found in the abdomen and pelvis, while a smaller percentage occurs in the thorax and head and neck regions. Diaphragmatic paragangliomas are exceedingly rare, with only two documented cases in the literature. This report details a case of a primary diaphragmatic paraganglioma in a 59-year-old patient presenting with unexplained weight loss, tremors, and diaphoresis. Imaging studies revealed a mass in the right lobe of the liver, later identified as a diaphragmatic paraganglioma during surgery. The case underscores the importance of preoperative catecholamine assessment and careful surgical planning due to the risks associated with tumor manipulation. Complete surgical resection, although challenging, remains the definitive treatment, especially in hypervascular tumors located near major vascular structures.

[Endothelial cells and fibroblasts mediate the microenvironmental regulatory network of carotid body paraganglioma]

Objective:To explore the gene expression characteristics of endothelial cells and fibroblasts in the microenvironment of SDHD-mutated carotid body tumors（SDHD-CBT）, to fine the functional enrichment of each subcluster, and to further explore the network of cell-cell interactions in the microenvironment of SDHD-CBT. Methods:The bioinformatics analysis was used to download and reanalyze the single-nuclear RNA sequencing data of SDHD-CBT, SDHB mutated thoracic and abdominal paraganglioma（SDHB-ATPGL）, SDHB-CBT, and normal adrenal medulla（NAM）, to clarify the information of cell populations of the samples. We focused on exploring the gene expression profiles of endothelial cells and fibroblasts subclusters, and performed functional enrichment analysis based on Gene Ontology（GO） resources. CellChat was used to compare the cell-cell interactions networks of different clinical samples and predict significant signaling pathways in SDHD-CBT. Results:A total of 7 cell populations were profiled. The main subtypes of endothelial cells in SDHD-CBT are arterial and venous endothelial cells, and the main subtypes of fibroblasts are myofibroblasts and pericytes. Compared to NAM, SDHB-CBT and SDHB-ATPGL, cell communication involving endothelial cells and fibroblasts in SDHD-CBT is more abundant, with significant enrichment in pathways such as FGF, PTN, WNT, PROS, PERIOSTIN, and TGFb. Conclusion:Endothelial cells and fibroblasts in SDHD-CBT are heterogeneous and involved in important cellular interactionprocesses, in which the discovery of FGF，PTN，WNT，PROS，PERIOSTIN and TGFb signals may play an important role in the regulation of microenvironment of SDHD-CBT.

[Advance in HIF expression and immune microenvironment in pseudohypoxic HNPGL]

This article systematically reviewed the pathological features, molecular mechanisms, and tumor microenvironment of head and neck paraganglioma（HNPGL）, with a focus on pseudohypoxic HNPGL. It was demonstrated that pseudohypoxic HNPGL mainly involves multiple gene mutations, such as SDHx and VHL/EPAS1, which affect the stability and activity of HIF protein and exacerbate the development of the tumor. Meanwhile, the paper also analyzed the expression patterns of HIF-1α and HIF-2α in HNPGL, and found that differences in HIF activation may have an impact on the therapeutic response of specific subtypes. In addition, the paper explored the tumor microenvironment of HNPGL and found that immune cells such as macrophages, CD4⁺T cells, and CD8⁺T cells play an important role in the tumor, and the heterogeneity of the immune microenvironment also affects the choice of therapeutic approaches and responsiveness. Through comprehensive analysis, these findings not only contribute to a deeper understanding of the pathogenesis and developmental process of HNPGL, but also provide clues for future personalized treatments for specific subtypes.

Attempted Removal of a Large Pheochromocytoma via a Robotic Approach

A pheochromocytoma is a rare tumor of neuroendocrine origin that secretes hormones like epinephrine, norepinephrine, and occasionally dopamine. The most notable symptom of the release of catecholamines is exceedingly high blood pressure. A 45-year-old male presented with a symptomatic pheochromocytoma of large size. He reported experiencing fatigue, orthopnea, dizziness, headache, and chest tightness with deep inspiration for several months. At the time of presentation, he was found to be in hypertensive emergency and was started on alpha-blockade for several days followed by a beta-blockade for a total of 28 days of anti-hypertensive treatment. During his admission, CT imaging showed his tumor to measure at least 14 cm in length, larger than most. After stabilization of the patient, an attempt was made to resect the tumor robotically, but the procedure was converted to an open left adrenalectomy owing to the size of the tumor and the number of tributaries. The patient tolerated the procedure well and, afterward, his blood pressure normalized. He recovered postoperatively with minimal hypotensive episodes and was started on physical therapy. This report reviews the details and management of this case.

Single-cell RNA-Seq reveals the heterogeneity of fibroblasts within the tympanojugular paraganglioma microenvironment

Tympanojugular paragangliomas (TJP) originate from the parasympathetic ganglia in the lateral base of the skull. Although the cellular composition and oncogenic mechanisms of paragangliomas have been evaluated, a comprehensive transcriptomic atlas specific to TJP remains to be established to facilitate further investigations. In this study, single-cell RNA sequencing and whole-exome sequencing were conducted on six surgically excised TJP samples to determine their cellular composition and intratumoral heterogeneity. Fibroblasts were sub-classified into two distinct groups: myofibroblasts and fibroblasts associated with bone remodeling. Additionally, an elaborate regulatory and cell-cell communication network was determined, highlighting the multifaceted role of fibroblasts, which varies depending on expression transitions. The Kit receptor (KIT) signaling pathway mediated interactions between fibroblasts and mast cells, whereas robust connections with endothelial and Schwann cell-like cells were facilitated through the platelet-derived growth factor signaling pathway. These findings establish a foundation for studying the mechanisms underlying protumor angiogenesis and the specific contributions of fibroblasts within the TJP microenvironment. IL6 signaling pathway of fibroblasts interacting with macrophages and endothelial cells may be involved in tumor regrowth. These results enhance our understanding of fibroblast functionality and provide a resource for future therapeutic targeting of TJP.

A case of successful management for spontaneous rupture of paraganglioma treated with preoperative transcatheter arterial embolization

BACKGROUND

Tumors arising from catecholamine-producing chromophil cells in paraganglia are termed paragangliomas (PGLs), which biologically resemble pheochromocytomas (PCCs) that arise from the adrenal glands. Spontaneous rupture of a PGL is rare and can be fatal. Although elective surgery for ruptured PCCs after transcatheter arterial embolization (TAE) has been shown to provide good outcomes, the efficacy of TAE pretreatment for ruptured PGL remains unknown.

CASE PRESENTATION

A 65-year-old female with hypertension and tachycardia was diagnosed with a 3-cm PGL located behind the inferior vena cava. The patient was scheduled to undergo an elective surgery with antihypertensive therapy. However, she presented with a chief complaint of abdominal pain and was diagnosed with intratumoral hemorrhage. Urgent TAE was performed that successfully achieved hemorrhage control. After TAE, serum levels of both epinephrine and norepinephrine were within the normal range. Abdominal computed tomography revealed resolving retroperitoneal hematoma. Elective open surgery was performed without significant intraoperative bleeding or fluctuations in blood pressure.

CONCLUSION

We report a case of successful preoperative TAE for functional PGL to control intraoperative blood pressure fluctuations and bleeding. Preoperative TAE could be a useful procedure for the surgical preparation of functional PGL, including unruptured cases.

Neurofibromatosis Type 1: Optimizing Management with a Multidisciplinary Approach

Neurofibromatosis Type I (NF1) is a complex genetic condition that affects multiple organ systems and presents a unique set of challenges for clinicians in its management. NF1 is a tumor predisposition syndrome that primarily affect the peripheral and central nervous systems via the impact of haploinsufficiency upon neural crest lineage cells including Schwann cells, melanocytes, fibroblasts, etc. NF1 can further lead to pathology of the skin, bones, visual system, and cardiovascular system, all of which can drastically reduce a patient's quality of life (QOL). This review provides a comprehensive examination of the many specialties required for the care of patients with Neurofibromatosis Type 1 (NF1). We delve into the pathogenesis and clinical presentation of NF1, highlighting its diverse manifestations and the challenges they pose in management. The review underscores the importance of a multidisciplinary approach to NF1, emphasizing how such an approach can significantly improve patient outcomes and overall QOL. Central to this approach is the role of the NF expert, who guides a multidisciplinary team (MDT) comprising healthcare professionals from many areas of expertise. The MDT collaboratively addresses the multifaceted needs of NF1 patients, ensuring comprehensive and personalized care. This review highlights the need for further investigation to optimize the workflow for NF1 patients in an MDT setting, and to improve implementation and efficacy.

Endocrine and non-endocrine causes of fatigue in adults with Neurofibromatosis type 1

Context

Neurofibromatosis type 1 (NF1) is a complex system disorder, caused by alterations in RAS pathways. NF1 adults often suffer from chronic and severe fatigue, for which they are frequently referred to Internal Medicine/Endocrinology. Seeking medical help often leads to (invasive) diagnostic procedures. To prevent the personal and financial burden of this disabling fatigue, it is crucial to know the causes.

Objective

To explore somatic causes and provide practical recommendations for the approach to fatigue in adults with NF1.

Design

Cross-sectional. All adults with NF1 (N = 133) who visited our Endocrinology department underwent a systematic health screening, including a medical questionnaire, structured interview, complete physical examination, biochemical measurements and additional tests if indicated.

Main outcome measure

Prevalence of endocrine and non-endocrine health problems between NF1 adults with and without fatigue.

Results

In our cohort, 75% of NF1 adults experienced fatigue. The most frequent endocrine disorders were vitamin D deficiency (28%), obesity (18%) and hypothyroidism (8%). The most frequent non-endocrine internal disorder was high blood pressure (42%). None of the disorders differed significantly between adults with and without fatigue.

Conclusions

Endocrine and non-endocrine disorders were equally present in our cohort of NF1 adults with and without fatigue. This suggests that the high prevalence of fatigue in NF1 adults is not explained by these somatic disorders. An alternative explanation for fatigue might be deficits in cognitive functioning and other neuropsychological processes in NF1. Based on our results and review of the literature, we provide a clinical algorithm for the approach to fatigue in NF1 adults, including somatic and psychological assessment.

Adrenal pheochromocytoma impacts three main pathways: cysteine-methionine, pyrimidine, and tyrosine metabolism

Pheochromocytomas and paragangliomas (PPGLs) cause symptoms by altering the circulation levels of catecholamines and peptide hormones. Currently, the diagnosis of PPGLs relies on diagnostic imaging and the detection of catecholamines. In this study, we used ultra-performance liquid chromatography (UPLC)/quadrupole time-of-flight mass spectrometry (Q-TOF MS) analysis to identify and measure the perioperative differential metabolites in the plasma of adrenal pheochromocytoma patients. We identified differentially expressed genes by comparing the transcriptomic data of pheochromocytoma with the normal adrenal medulla. Through conducting two steps of metabolomics analysis, we identified 111 differential metabolites between the healthy group and the patient group, among which 53 metabolites were validated. By integrating the information of differential metabolites and differentially expressed genes, we inferred that the cysteine-methionine, pyrimidine, and tyrosine metabolism pathways were the three main metabolic pathways altered by the neoplasm. The analysis of transcription levels revealed that the tyrosine and cysteine-methionine metabolism pathways were downregulated in pheochromocytoma, whereas the pyrimidine pathway showed no significant difference. Finally, we developed an optimized diagnostic model of two metabolites, L-dihydroorotic acid and vanylglycol. Our results for these metabolites suggest that they may serve as potential clinical biomarkers and can be used to supplement and improve the diagnosis of pheochromocytoma.

Fluorescence-guided minimally-invasive resection of abdominal paragangliomas using indocyanine green

This retrospective study explores the utility of near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) in enhancing the intraoperative identification and guidance for the resection of abdominal paragangliomas. They can be challenging to detect during minimally invasive surgery, due to their anatomical location, varying size and similar appearance in regard to their surrounding tissue. Patients with suspected abdominal paragangliomas planned for a minimally-invasive resection were included. As part of standard of care they received single intravenous dose of 5 mg ICG after abdominal exploration. NIR fluorescence imaging of the anatomical region of the suspected lesion was performed immediately following intravenous administration, to assess fluorescence signals, intraoperative identification, and histopathological correlation. Out of five resected suspicious lesions, four were imaged with NIR fluorescence, pathology confirming four as paragangliomas, the latter turned out to be an adrenal adenoma. NIR fluorescence identified all four lesions, surpassing the limitations of white-light visualization. Homogeneous fluorescence signals appeared 30-60 s post-ICG administration, which lasted up to 30 min. The study demonstrates the feasibility and potential clinical value of fluorescence-guided minimally-invasive resections of abdominal paragangliomas using a single intravenous ICG dose. These findings support the scientific basis for routine use of ICG-fluorescence-guided surgery in challenging anatomical cases, providing valuable assistance in lesion detection and resection.

Hereditary and clinical insights into paraganglioma and pheochromocytoma

Background

Approximately 30-40% of paragangliomas (PGLs) and pheochromocytomas (PCCs) harbor an underlying hereditary cause. Early identification of at-risk individuals is imperative given the early onset, aggressiveness of tumors, and other tumor/cancer risks associated with hereditary PGLs/PCCs. This study analyzes the clinical presentations and genetic histories of patients with PGL/PCC and/or hereditary risk to contribute to the expanding knowledge in this rare population.

Methods

A retrospective chart review identified two cohorts of patients seen in cancer genetics clinics at an academic medical center and a safety-net hospital between August 2016 and December 2022. Cohort 1 consisted of patients with likely pathogenic variants (LPVs)/pathogenic variants (PVs) in hereditary PGL/PCC predisposition genes. Cohort 2 consisted of patients with a personal history of a PGL/PCC. Demographics, personal/family history, and genetic testing outcomes were analyzed.

Results

A total of 560 patients met the study criteria (Cohort 1, n = 364; Cohort 2, n = 269). In Cohort 1, 77 (21.1%) patients had an incidental LPV/PV in a PGL/PCC gene. Nearly half (n = 36, 46.8%) were in SDHx genes, with a majority in SDHA (n = 21). In Cohort 2, 86 patients tested positive for 87 LPV/PV in a hereditary cancer predisposition gene. The SDHx genes were most likely to have an LPV/PV identified (SDHB n = 24, SDHD n = 23).

Conclusions

Multigene panels identify patients at risk for hereditary PGL/PCC, many of whom are incidentally found. While SDHA LPV/PVs were the most frequent incidental finding, they were less common in patients with PGL/PCC, indicating the need for longitudinal studies to better understand the prevalence and penetrance of these tumors.

Imaging Pathway of a Pediatric Patient with Succinate Dehydrogenase B-Deficient Paraganglioma

Pheochromocytoma and paraganglioma are rare in children, at only 1 in every 50,000 cases. Even though some cases are sporadic, they have been connected to syndromes such as von Hippel-Lindau, multiple endocrine neoplasia types IIa and IIb, neurofibromatosis type 1, and hereditary pheochromocytoma-paraganglioma syndromes. A genetic mutation causes around 60% of pheochromocytomas and paragangliomas in children under 18. Methods: A 15-y-old child with a 6-y history of back discomfort is presented. The justification for using 2 functional imaging modalities, 68Ga-DOTATATE PET/CT and 123I-meta-iodobenzylguanidine SPECT/CT, is examined in this case study. We reviewed the patients' journey since the first referral for imaging. Results: Delaying the molecular imaging modalities has affected patients' overall diagnosis and applied treatment outcomes. Conclusion: This case study investigates the potential for the earlier use of various diagnostic modalities in conjunction with diagnostic testing to facilitate an earlier diagnosis. However, since this study is based solely on imaging and lacks access to the patient's clinical or family history, factors such as potential inequities in health-care facilities, health literacy, and socioeconomic status are not addressed. It is essential to acknowledge these influences as they contribute to the inequitable access to health-care settings in New Zealand.

Skull Base Tumors

OBJECTIVE

This article reviews the presenting features, molecular characteristics, diagnosis, and management of selected skull base tumors, including meningiomas, vestibular schwannomas, pituitary neuroendocrine tumors, craniopharyngiomas, chordomas, ecchordosis physaliphora, chondrosarcomas, esthesioneuroblastomas, and paragangliomas.

LATEST DEVELOPMENTS

Skull base tumors pose a management challenge given their complex location and, as a result, the tumors and treatment can result in significant morbidity. In most cases, surgery, radiation therapy, or both yield high rates of disease control, but the use of these therapies may be limited by the surgical accessibility of these tumors and their proximity to critical structures. The World Health Organization classification of pituitary neuroendocrine tumors was updated in 2022. Scientific advances have led to an enhanced understanding of the genetic drivers of many types of skull base tumors and have revealed several potentially targetable genetic alterations. This information is being leveraged in the design of ongoing clinical trials, with the hope of rendering these challenging tumors treatable through less invasive and morbid measures.

ESSENTIAL POINTS

Tumors involving the skull base are heterogeneous and may arise from bony structures, cranial nerves, the meninges, the sinonasal tract, the pituitary gland, or embryonic tissues. Treatment often requires a multidisciplinary approach, with participation from radiation oncologists, medical oncologists, neuro-oncologists, and surgical specialists, including neurosurgeons, otolaryngologists, and head and neck surgeons. Treatment has largely centered around surgical resection, when feasible, and the use of first-line or salvage radiation therapy, with chemotherapy, targeted therapy, or both considered in selected settings. Our growing understanding of the molecular drivers of these diseases may facilitate future expansion of pharmacologic options to treat skull base tumors.

Reference intervals for deconjugated urine metanephrines by Bhattacharya analysis

BACKGROUND

Urine metanephrines are used to screen for phaeochromocytoma or paraganglioma (PPGL). Current reference intervals (RI) derived in healthy individuals are not age or sex-stratified, and lower than in hypertensive patients, leading to high false positive rates. This study aims to determine age and sex-stratified RI from a contingent screening population.

METHODS

Patients with 24-h deconjugated urine metanephrines from 3/6/2010 to 27/8/2022 were included (2936 males, 5285 females), initially by liquid chromatography-electrochemical detection (LC-ECD) then liquid chromatography-tandem mass spectrometry (LC-MS/MS). Bhattacharya analysis was used after log transformation to determine age and sex-stratified RI for metanephrine excretion, normetanephrine excretion, metanephrine/creatinine and normetanephrine/creatinine ratios.

RESULTS

Normetanephrine excretion increases with age (RI: males: 18-<30 years: <3.4 µmol/24 h, 30-<40 years: <3.7 µmol/24 h, 40+ years: <5.3 µmol/24 h; females: 18-<30 years: <2.7 µmol/24 h, 30-<40 years: <3.1 µmol/24 h, 40+ years: <3.7 µmol/24 h), while metanephrine excretion was consistent across adulthood (RI: males: 18+ years: <1.8 µmol/24 h; females: 18+ years: <1.2 µmol/24 h). However, normetanephrine/creatinine and metanephrine/creatinine increase steadily with age after early adulthood, likely due to a decrease in muscle mass, with females having higher normetanephrine/creatinine and metanephrine/creatinine ratios.

CONCLUSIONS

Age and sex-stratified RI were derived for metanephrine excretion, normetanephrine excretion, metanephrine/creatinine and normetanephrine/creatinine ratios. This is expected to reduce false positives while flagging most PPGL.

Characterization of indocyanine green fluorescence imaging patterns of pheochromocytomas

BACKGROUND

Indocyanine green (ICG) fluorescence is a new intraoperative imaging modality for adrenal tumors. Previous work suggested that pheochromocytomas did not show fluorescence, but experience is limited. The objective of this study is to analyze fluorescence imaging patterns of pheochromocytomas.

METHODS

This was an IRB-approved retrospective study. Patients who underwent adrenalectomy with ICG imaging were identified from a departmental database. Intraoperative fluorescence patterns were analyzed by reviewing surgical videos. Descriptive and comparative statistical analyses were performed to determine factors associated with different fluorescence patterns of pheochromocytomas.

RESULTS

Of the 46 pheochromocytomas included, 50% (n = 23) exhibited fluorescence. Parameters predicting fluorescence on univariate analysis were age, tumor size and hereditary. On multivariate analysis, tumor size was the only predictive parameter of ICG fluorescence, with loss of fluorescence at a threshold of > 3.2 cm (p = 0.004).

CONCLUSIONS

This is the largest cohort to date assessing fluorescence properties of pheochromocytomas. In contrast to previous studies, we demonstrated that smaller pheochromocytomas do exhibit fluorescence. This may support the application of intraoperative ICG imaging for smaller or bilateral pheochromocytomas, which may assist in identification and/or cortical-sparing during adrenalectomy.

A pan-tissue survey of mosaic chromosomal alterations in 948 individuals

Genetic mutations accumulate in an organism's body throughout its lifetime. While somatic single-nucleotide variants have been well characterized in the human body, the patterns and consequences of large chromosomal alterations in normal tissues remain largely unknown. Here, we present a pan-tissue survey of mosaic chromosomal alterations (mCAs) in 948 healthy individuals from the Genotype-Tissue Expression project, augmenting RNA-based allelic imbalance estimation with haplotype phasing. We found that approximately a quarter of the individuals carry a clonally-expanded mCA in at least one tissue, with incidence strongly correlated with age. The prevalence and genome-wide patterns of mCAs vary considerably across tissue types, suggesting tissue-specific mutagenic exposure and selection pressures. The mCA landscapes in normal adrenal and pituitary glands resemble those in tumors arising from these tissues, whereas the same is not true for the esophagus and skin. Together, our findings show a widespread age-dependent emergence of mCAs across normal human tissues with intricate connections to tumorigenesis.

[Metastatic risk factors in pheochromocytoma/paraganglioma]

Currently, all pheochromocytoma/paraganglioma (PPGLs) are considered malignant due to metastatic potential. Consequently, PPGLs are divided into «metastatic» and «non-metastatic». Metastatic PPGLs can be with synchronous metastasis (metastases appear simultaneously with the identified primary tumor) or metachronous (metastases develop after removal of the primary tumor). The term metastatic PPGLs is not used in the presence of tumor invasion into surrounding organs and tissues, without the presence of distant metastases of lymphogenic or hematogenic origin. It is generally believed that about 10% of pheochromocytomas and about 40% of sympathetic paragangliomas have metastatic potential. On average, the prevalence of PPGLs with the presence of metastases is 15-20%. Risk factors for metastatic PPGLs are widely discussed in the literature, the most significant of which are groups of clinical, morphological and genetic characteristics. The review presents a discussion of such risk factors for metastatic PPGLs as age, localization and type of hormonal secretion of the tumor, the size and growth pattern of the adrenal lesion, the presence of necrosis and invasion into the vessels, the tumor capsule surrounding adipose tissue, high cellular and mitotic activity, Ki-67 index, expression of chromogranin B and S100 protein, the presence of genetic mutations of three main clusters (pseudohypoxia, kinase signaling and Wnt signaling).Over the past two decades, a number of authors have proposed various predictor factors and scales for assessing a probability of metastatic PPGLs. The review contains detailed description and comparison of sensitivity and specificity of such predictor scales as PASS, GAPP, M-GAPP, ASES and COPPS.

Catecholamine Surge in the Emergency Department: A Tech-Knowledgy-Preventable Pheochromocytoma Crisis

A patient with a known pheochromocytoma was admitted to the emergency department with hypertension and headache. Because of the disease rarity, the potential medication-disease interactions were not recognized. The patient received a dose of prochlorperazine to treat their headache. Prochlorperazine is a potential trigger of pheochromocytoma crisis. The patient developed worsening hypertension, pulmonary edema, and demand non-ST segment elevation myocardial infarction. In response, our health system has created a best-practice advisory within our electronic medical records that can alert a provider to interactions between medications and pheochromocytoma. We are looking to expand this practice to include other pathologies with dangerous medication interactions, and we recommend other health systems create similar initiatives.

SDHB exon 1 deletion: A recurrent germline mutation in Colombian patients with pheochromocytomas and paragangliomas

Pheochromocytomas (PCCs) and paragangliomas (PGLs) (known as PPGL in combination) are rare neuroendocrine tumors of the adrenal medulla and extra-adrenal ganglia. About 40% of the patients with PPGL have a hereditary predisposition. Here we present a case-series of 19 unrelated Colombian patients with a clinical diagnosis of PPGL tumors that underwent germline genetic testing as part of the Hereditary Cancer Program developed at the Instituto Nacional de Cancerología, Colombia (INC-C), the largest reference cancer center in the country. Ten of 19 patients (52.63%) were identified as carriers of a pathogenic/likely pathogenic (P/LP) germline variant in a known susceptibility gene. The majority of the P/LP variants were in the SDHB gene (9/10): one corresponded to a nonsense variant c.268C>T (p.Arg90*) and eight cases were found to be carriers of a recurrent CNV consisting of a large deletion of one copy of exon 1, explaining 42% (8/19) of all the affected cases. Only one additional case was found to be a carrier of a missense mutation in the VHL gene: c.355T>C (p.Phe119Leu). Our study highlights the major role of SDHB in Colombian patients with a clinical diagnosis of PGL/PCC tumors and supports the recommendation of including the analysis of large deletions/duplications of the SDHB gene as part of the genetic counselling to improve the detection rate of hereditary cases and their clinical care.

Novel and recurrent genetic variants of VHL, SDHB, and RET genes in Chinese pheochromocytoma and paraganglioma patients

Background: Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors arising from chromaffin cells in the adrenal medulla and extra-adrenal ganglia, respectively. The study was aimed to investigate the clinical and genetic characteristics of 22 individuals from six families. Methods: The medical records of six PPGL probands who presented to our hospital between 2016 and 2021 were retrospectively studied. DNA isolated from the probands was analyzed using whole exome sequencing. The identified genetic variants were confirmed by Sanger sequencing and undergone bioinformatic analysis. Results: Six different genetic variants in the six probands were identified, respectively, of which three were novel. A novel von Hippel-Lindau (VHL) variant, c.602T>C (p.L201P), in exon 3 was found. Two novel genetic variants in SDHB (succinate dehydrogenases subunit B), c.423 + 1 G>T and c.662A>G (p.D221G), were identified. Two recurrent genetic variants of VHL, c.C284G (p.P95R) and c.558_560AGAdel (p.186Edel), and one in RET (ret proto-oncogene), c.1901G>A (p.C634Y), were also found. The ClinVar accession number for the present variants are SCV002028348, and SCV002028352 to SCV002028361. Conclusion: Genetic variants in VHL, SDHB and RET were identified in Chinese PPGL patients, which contributed to the knowledge of the genetic etiology and clinical outcome of these tumors.

Unusual case of infrarenal pheochromocytoma developed on ectopic adrenal tissue: An autopsy case report

Introduction: Pheochromocytomas are catecholamine-secreting tumors arising from the chromaffin cells of the adrenal medulla. We describe an unusual case of pheochromocytoma located in the infrarenal area and associated with bilateral adrenal hyperplasia.

Case presentation: A 70-year-old patient was admitted for syncope, diaphoresis, and high blood pressure. Computed tomography showed a 73×70×72 mm retroperitoneal mass of the left infrarenal area. High levels of metanephrine and noradrenaline were found in the urine. A tumor resection was performed. A few days after surgery, the blood pressure suddenly decreased and could not be restored, resulting in the death of the patient. Histopathological examination of the surgical specimen revealed a proliferation of monotonous cells, with eosinophilic cytoplasm, round nuclei with prominent nucleoli arranged in clusters, and capsular and vascular invasion. The tumor cells expressed synaptophysin and chromogranin, without positivity for inhibin A or S100 protein. At the autopsy, both adrenal glands showed hyperplasia but unrelated to the tumor mass. The histological aspect, location, and immunophenotype indicated an ectopic infrarenal pheochromocytoma.

Conclusions: In patients with pheochromocytoma developed on ectopic adrenal tissue, clinical management might be difficult, and diagnosis can be sometimes established only based on post-mortem histopathological examination. Autopsy can be extremely useful in such cases with unexplained evolution.

Hypertensive Urgency Secondary to a Malignant Pheochromocytoma and Its Complex Treatment Course: A Case Report

Pheochromocytoma originates from the chromaffin cells of the adrenal medulla. It produces an excess of catecholamines. It is essentially a benign tumour, and the malignant type represents a minority. The malignant behaviour can be unclear in the absence of metastases. Factors of poor prognosis in malignant pheochromocytoma include male sex, old age, large-sized tumours, the presence of metastases at the time of diagnosis and non-surgical treatment. The cornerstone treatment of pheochromocytoma is surgical excision. In the presence of metastases, chemotherapy can control the symptoms and prolong survival. Its reported side effects are usually few and mild.

This report presents a rare case of malignant pheochromocytoma in a 26-year-old gentleman that first manifested as a hypertensive urgency. The patient had several recurrences and multiple metastases despite two surgical excisions. Such poor outcome could not be predicted initially by the known risk factors. A non-previously reported complication of treatment was acute lower limb ischaemia after the start of chemotherapy for the tumour, depriving the patient of completing the course.

In conclusion, the presence of hypertension in young adults warrants the investigation for pheochromocytoma. Postoperative follow-up is mandatory to pick up early signs of malignancy and metastasis. Tumour breakdown by chemotherapy can cause various cardiovascular problems including acute limb ischaemia. The management can be quite challenging, therefore, a multidisciplinary team should look after the case. A palliative approach can be used in patients with severe symptoms and no chance of cure.

Biobanking potential for biomedical research in endocrinology

Biobanking is an actively developing scientific area that provides tools for conducting biomedical research, increasing the reliability and reproducibility of their results. In endocrinology, more and more attention is paid to the study of molecular and genetic markers of diseases for the selection of new points of influence in treatment, the development of targeted therapy and a strategy for personalized prevention. This approach is designed to solve the problems of endocrine disorders, their complications, causing significant damage to the individual and he population health, and reduce the financial burden of chronic endocrine disorders. To increase the reliability and reproducibility of research results, requirements for working with biological material should be strictly complied. The use of biobanking will increase the validity of data obtained in clinical trials in endocrinology. There are successful examples of Russian and foreign studies using the capabilities of biobanks aimed at studying diabetes, polycystic ovary syndrome, adenomas and other endocrine disorders. The article discusses the prospects for partnership with biobanks in the framework of endocrinology research. The purpose of this review is to analyze the literature to systematize knowledge for application of biobanking in biomedical research in the field of endocrinology.

Diagnosing Pheochromocytoma in the COVID-19 Era: A Case Report

Introduction

Pheochromocytomas and paragangliomas are rare neuroendocrine tumors that secrete catecholamines. Symptoms of these tumors are related directly to catecholamine excess but can be intermittent and easily misattributed to other, more common pathologies. Identification in the emergency department (ED) is inherently difficult. During the coronavirus 2019 (COVID-19) pandemic, physicians have had to account for both the disease itself as well as associated increased prevalence of cardiac, pulmonary, and vascular complications. Such shifting of disease prevalence arguably makes rarer diseases like pheochromocytoma less likely to be recognized.

Case Report

We report a case of pheochromocytoma in a patient who presented to the ED in the fall of 2020, at a regional height of the COVID-19 pandemic, with complaints of fatigue, tachycardia, and diaphoresis. The differential diagnosis included pulmonary embolism, cardiomyopathy, congestive heart failure, and infectious causes. A broad workup was begun that included serology, electrocardiogram, computed tomography angiogram (CTA), and COVID-19 testing. Imaging was consistent with COVID-19 infection, and laboratory testing confirmed the diagnosis. A tiny retroperitoneal tumor was reported on CTA as “incidental” in the setting of multifocal pneumonia from severe acute respiratory syndrome coronavirus 2 infection. Additional history-taking revealed many years of intermittent symptoms suggesting that the tumor may have been more contributory to the patient’s presentation than originally suspected. Subsequent magnetic resonance imaging and surgical pathology confirmed the dual diagnosis of pheochromocytoma and COVID-19 pneumonia.

Conclusion

This case presentation highlights the importance of careful history-taking, keeping a broad differential, and examining incidental findings in the context of the patient’s presentation.

Cardiovascular implications in adolescent and young adult hypertension

Background

Hypertension is one of the most prevalent diseases in the United States, affecting an estimated 3.5% of children and adolescents. It can be adversely affect most organ systems but is particularly detrimental to the heart and vascular systems. The repercussions can be gauged through well-established measures of cardiovascular function including left ventricular mass index (LVMI), left ventricular hypertrophy (LVH), carotid intima media thickness (cIMT), and aortic stiffness. Cardiovascular function is also affected by underlying etiologies of hypertension including chronic kidney disease, polycystic kidney disease, coarctation of the aorta, adrenal disorders, renal artery stenosis, obstructive sleep apnea, as well as various drugs and medications (decongestants, stimulants, Non-steroidal Anti-inflammatory Drugs (NSAIDs), and steroids).

Methods

An exhaustive literature search was conducted for clinical data regarding pediatric hypertension. Sixty-seven articles were incorporated with data on 189,477 subjects total. The data was then extracted and categorized as relating to hypertension incidence, LVMI, LVH, cIMT, and/or aortic stiffness.

Results

The prevalence of pediatric ( < 18 years) hypertension extracted from 47 studies from 1994 to 2018 averaged 4%. The LVMI assessed over 7 studies (n = 661) averaged 39.3 g/ m 2.7 in the hypertensive cohort and 30.1 g/ m 2.7 in the control cohort. The cIMT assessed over 7 studies (n = 580) averaged 0.55 mm in the hypertensive cohort and 0.49 mm in the control cohort. Ambulatory arterial stiffness parameters assessed over 5 studies (n = 573) in the normotensive cohort averaged 99.73 mmHg, 69.81 mmHg, 76.85 mmHg, and 46.90 mmHg, for SBP, DBP, MAP, and PP respectively. Ambulatory arterial stiffness parameters assessed over 5 studies (n = 573) in the hypertensive cohort averaged 129.56 mmHg, 73.69 mmHg, 95.08 mmHg, and 56.80 mmHg, for SBP, DBP, MAP, and PP respectively.

Conclusions

The significance of pediatric hypertension is emphasized by evidence of early cardiovascular disease as demonstrated by non-invasive measures including cIMT and arterial stiffness parameters, and target organ damage and including LVH and LVMI factors. Thus, early diagnosis and treatment of high blood pressure is paramount for improving long term cardiovascular health and preventing long term morbidity and mortality.

A Predictive Nomogram for Early Death in Pheochromocytoma and Paraganglioma

Background

Pheochromocytoma (PHEO) and paraganglioma (PGL) are relatively rare neuroendocrine tumors. The factors affecting patients with early death remain poorly defined. We aimed to study the demographic and clinicopathologic pattern and to develop and validate a prediction model for PHEO/PGL patients with early death.

Methods

Data of 800 participants were collected from the Surveillance Epidemiology and End Results (SEER) database as a construction cohort, while data of 340 participants were selected as a validation cohort. Risk factors considered included the year of diagnosis, age at diagnosis, gender, marital status, race, insurance status, tumor type, primary location, laterality, the presence of distant metastasis. Univariate and multivariate logistic regressions were performed to determine the risk factors. R software was used to generate the nomogram. Calibration ability, discrimination ability, and decision curve analysis were analyzed in both construction and validation cohorts.

Results

PHEO and PGL patients accounted for 54.3% (N=434) and 45.7% (N=366), respectively. More than half of tumors (N=401, 50.1%) occurred in the adrenal gland, while 16.9% (N=135) were in aortic/carotid bodies. For the entire cohort, the median overall survival (OS) was 116.0 (95% CI: 101.5-130.5) months. The multivariate analysis revealed that older age (versus age younger than 31; age between 31 and 60: OR=2.03, 95% CI: 1.03-4.03, P=0.042; age older than 60: OR=5.46, 95% CI: 2.68-11.12, P&lt;0.001), female gender (versus male gender; OR=0.59, 95% CI: 0.41-0.87, P=0.007), tumor located in aortic/carotid bodies (versus tumor located in adrenal gland; OR=0.49, 95% CI: 0.27-0.87, P=0.015) and the presence of distant metastasis (versus without distant metastasis; OR=4.80, 95% CI: 3.18-7.23, P&lt;0.001) were independent risk factors of early death. The predictive nomogram included variables: age at diagnosis, gender, primary tumor location, and distant metastasis. The model had satisfactory discrimination and calibration performance: Harrell’s C statistics of the prediction model were 0.733 in the construction cohort and 0.716 in the validation cohort. The calibration analysis showed acceptable coherence between predicted probabilities and observed probabilities.

Conclusions

We developed and validated a predictive nomogram utilizing data from the SEER database with satisfactory discrimination and calibration capability which can be used for early death prediction for PHEO/PGL patients.

An Analysis of Computed Tomography Imaging Features and Predictive Factors for Postoperative Recurrence and Metastasis of Abdominal Paragangliomas

Methods

We studied 51 abdominal PGL patients at the First Affiliated Hospital of Bengbu Medical College, Tongde Hospital, and Sir Run Shaw Hospital, Hangzhou, Zhejiang Province, China, from June 2009 to May 2019. Thereafter, the clinical research data, tumor biomarkers, and CT features were compared between the aggressive PGLs and the nonaggressive PGLs using independent-samples t-tests and chi-square tests.

Results

Of the 51 cases, 43 were benign and 8 had malignant tendencies. Postoperative recurrence and metastasis were more likely to occur when the tumor diameter was >8 cm or/and the enhancement degree was not obvious. Clinical symptoms, tumor markers, sex, age, and CT image characteristics including morphology, presence of cystic degeneration, "pointed peach" sign, calcification, hemorrhage, enlarged lymph nodes, and peritumor and intratumor blood vessels were not significantly different between the two groups (p > 0.05).

Conclusion

Our findings suggest that CT features, including size >8 cm and enhancement degree, could provide important evidence to assess risk factors for aggressive PGLs.

[Clinical and laboratory features of hereditary pheochromocytoma and paraganglioma]

The widespread introduction of genetic testing in recent years has made it possible to determine that more than a third of cases of pheochromocytomas and paragangliomas (PPPGs) are caused by germline mutations. Despite the variety of catecholamine-producing tumors manifestations, there is a sufficient number of clinical and laboratory landmarks that suggest a hereditary genesis of the disease and even a specific syndrome. These include a family history, age of patient, presence of concomitant conditions, and symptoms of the disease. Considering that each of the mutations is associated with certain diseases that often determine tactics of treatment and examination of a patient, e.g. high risk of various malignancies. Awareness of the practitioner on the peculiarities of the course of family forms of PPPGs will allow improving the tactics of managing these patients.The article provides up-to-date information on the prevalence of hereditary PPPGs. The modern views on the pathogenesis of the disease induced by different mutations are presented. The main hereditary syndromes associated with PPPGs are described, including multiple endocrine neoplasia syndrome type 2A and 2B, type 1 neurofibromatosis, von Hippel-Lindau syndrome, hereditary paraganglioma syndrome, as well as clinical and laboratory features of the tumor in these conditions. The main positions on the necessity of genetic screening in patients with PPPGs are given.

Neuroendocrine neoplasia and bone (Review)

This is a narrative review focusing on neuroendocrine neoplasia (NEN) and bone status, in terms of metastases and osteoporosis/fractures. One fifth of NEN have skeletal dissemination, this affinity being regulated by intrinsic tumor factors such as the C-X-C chemokine receptor 4 (CXCR4). Bone colonization impairs the patient quality of life, representing a surrogate of reduced survival. Patients with NEN without bone metastases may exhibit low bone mineral density, perhaps carcinoid-related osteoporosis, yet not a standardized cause of osteoporosis. Case-finding strategies to address bone health in NEN with a good prognosis are lacking. Contributors to fractures in NEN subjects may include: menopausal status and advanced age, different drugs, induced hypogonadism, malnutrition, malabsorption (due to intestinal resection, carcinoid syndrome), hypovitaminosis D, impaired glucose profile (due to excessive hormones such as glucagon, somatostatinoma or use of somatostatin analogues), various corticoid regimes, and high risk of fall due to sarcopenia. Pheocromocytoma/paraganglioma involve bone through malignant forms (bone is an elective site) and potential secondary osteoporosis due to excessive hormonal content and increased sympathetic activity which is a key player of bone microarchitecture/quality as reflected by low Trabecular Bone Score. Glucocorticoid osteoporosis is related to NEN-associated ectopic Cushing syndrome. Currently, there are a lack of studies to emphasis that excessive gut-derivate serotonin in NENs with carcinoid syndrome is a specific activator of bone loss thus a contributor to carcinoid-related osteoporosis.

SDHB-Associated Paraganglioma Syndrome in Africa-A Need for Greater Genetic Testing

A germline mutation is identified in almost 40% of pheochromocytoma/paraganglioma (PPGL) syndromes. Genetic testing and counseling are essential for the management of index cases as well as presymptomatic identification and preemptive management of affected family members. Mutations in the genes encoding the mitochondrial enzyme succinate dehydrogenase (SDH) are well described in patients with hereditary PPGL. Among patients of African ancestry, the prevalence, phenotype, germline mutation spectrum, and penetrance of SDH mutations is poorly characterized. We describe a multifocal paraganglioma in a young African male with an underlying missense succinate dehydrogenase subunit B (SDHB) mutation and a history of 3 first-degree relatives who died at young ages from suspected cardiovascular causes. The same SDHB mutation, Class V variant c.724C>A p.(Arg242Ser), was detected in one of his asymptomatic siblings. As there are limited data describing hereditary PPGL syndromes in Africa, this report of an SDHB-associated PPGL is a notable contribution to the literature in this growing field. Due to the noteworthy clinical implications of PPGL mutations, this work highlights the existing need for broader genetic screening among African patients with PPGL despite the limited healthcare resources available in this region.

Emergent transcatheter arterial embolization to control critical blood pressure fluctuation associated with hypercatecholaminemic crisis in a patient with an unruptured retroperitoneal paraganglioma

Pheochromocytoma/paraganglioma (PPGL)-related hypercatecholaminemic crisis is a rare lethal condition caused by uncontrolled catecholamine secretion, occasionally leading to critical fluctuation in blood pressure (BP). Emergent transcatheter arterial embolization (TAE) has been employed for spontaneous PPGL rupture, but never, to our knowledge, for critical fluctuation in BP associated with PPGL-related hypercatecholaminemic crisis. We describe here our experience utilizing this method to control critical fluctuation in BP associated with this crisis in a 44-year-old man with an unruptured retroperitoneal paraganglioma. The patient experienced sudden severe left abdominal pain and came to our emergency department, where he exhibited severe fluctuation in BP and underwent laboratory testing that showed hypercatecholaminuria and computed tomography (CT) that revealed a left retroperitoneal tumor with no apparent intra- or retroperitoneal hematoma. We performed emergent TAE from the left inferior phrenic artery using gelatin sponge, which stabilized his BP and relieved his abdominal pain. Histologic examination following elective surgical resection of the tumor confirmed our diagnosis of unruptured retroperitoneal paraganglioma. We believe that TAE represents an important option for the emergent treatment of the critical BP fluctuation associated with PPGL-related hypercatecholaminemic crisis.

Diaphragmatic Paraganglioma in an Adolescent Male

Paragangliomas are an infrequent type of neuroendocrine tumor that commonly produces catecholamines. We describe a case of a 14-year-old male with a history of uncontrolled hypertension who presented to the emergency department with a headache, palpitations, and profuse sweating. Symptoms were explained by the presence of a catecholamine-producing paraganglioma located at the right diaphragm. One year after radical surgical resection, the patient remains normotensive and does not require hypertensive medications.

Pheochromocytoma Presenting as Testicular Pain: An Unusual Case Report

Pheochromocytoma (PCC) is a rare catecholamine-secreting tumor that arises from chromaffin cells of the adrenal medulla which are derived from the neural crest. This report illustrates a 51-year-old Caucasian male with a history of hypertension diagnosed two years ago who presented to the hospital due to acute onset of right testicular pain of 3-day duration. Laboratory results and imaging revealed a presumptive diagnosis of PCC. The patient had undergone robot-assisted laparoscopic right adrenalectomy 14 days after being diagnosed with PCC due to perioperative management with phenoxybenzamine. The final pathology report revealed a PCC. At follow-up two weeks after discharge, the patient reported complete resolution of his testicular pain.

Pheochromocytoma of the organ of Zuckerkandl

Paragangliomas are uncommon neuroendocrine neoplasms that occur in characteristic locations. While parasympathetic paragangliomas are mainly located at the head and neck, sympathetic paragangliomas are mostly located below the neck. Among parasympathetic paragangliomas, pheochromocytomas are the most common. Ninety percent of cases of pheochromocytomas arise within the adrenal gland. We report a case of a 63-year-old woman with an extra-adrenal pheochromocytoma of the organ of Zuckerkandl detected by CT and MRI and subsequently confirmed by postoperative histology and immunohistochemistry.

Incidental Diagnosis of Multiple Paragangliomas by Ga-68 DOTANOC Positron Emission Tomography-Computed Tomography

A 65-year-old man presented with intermittent abdominal pain for three months. Abdominal ultrasonography revealed a mass in the body of the pancreas. Moreover, abdominal contrast-enhancing computed tomography revealed a homogenously enhancing mass in the body of the pancreas. Scan findings were in favor of the neuroendocrine tumor, and the serum chromogranin level was slightly raised (111.9 ng/ml, normal <98). He had no history of vomiting, jaundice, melena, hematemesis, constipation, diarrhea, weight gain, weight loss, loss of appetite, and fever. He also had no symptoms related to the excessive production of catecholamines, such as hypertension. The patient was referred for Ga-68 DOTANOC positron emission tomography-computed tomography (Ga-68 DOTANOC PET-CT) for further evaluation. The scan was done to rule out metastatic disease or other synchronous lesions to plan surgical excision. The Ga-68 DOTANOC PET-CT revealed a pancreatic lesion with no other abdominal lesions. We noted multiple tracer avid soft tissue lesions on both sides of the neck that were not diagnosed previously. This case report demonstrates a rare case with multiple paragangliomas diagnosed by the Ga-68 DOTANOC PET-CT. This finding could lead to changes in patient management.

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.

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.