Overview of the 2022 WHO Classification of Paragangliomas and Pheochromocytomas

Prognostic significance of Ki-67 in assessing the risk of progression, relapse or metastasis in pheochromocytomas and paragangliomas

INTRODUCTION

Since the Fourth edition of the WHO classification, PPGLs have been recognized for their metastatic potential, though no clear features can accurately predict this behavior. The prognostic value of Ki-67 in assessing the risk of progression, relapse, or metastasis in PPGLs remains debated.

METHODS

This cohort study included 501 patients diagnosed with PPGLs at the First Hospital of Jilin University between 2000 and 2022, with clinical data, treatment details, pathological indicators, and germline gene test results collected. Bulk sequencing was performed on formalin-fixed paraffin-embedded (FFPE) primary tumor samples from 87 patients. Progression-free survival (PFS) was analyzed using multivariable Cox regression.

RESULTS

Among the 119 enrolled patients with PPGLs, the average age was 45.7 ± 14.0 years, and the median follow-up time was 46 months. A significant finding was the high expression of CDK1, a gene known to be significantly associated with the metastatic risk of PPGLs, in samples with Ki-67 ≥ 3% (p < 0.0001). More importantly, patients with PPGLs and a Ki-67 level ≥ 3% had a 3.59-fold higher risk of progression, relapse or metastasis compared to those with Ki-67 < 3% (HR = 4.59, 95% CI: 1.06-11.95), after adjusting for all confounding factors. In the composite model, the addition of Ki-67 enhanced the predictive ability of the combined model of SDHB, primary site, tumor size, and invade neighboring tissue (AUC = 0.888, 95% CI: 0.808-0.967 vs. AUC = 0.874, 95% CI: 0.783-0.965).

CONCLUSION

A Ki-67 level ≥ 3% is associated with an increased risk of progression, relapse or metastasis in patients with PPGLs.

Nervous system in hepatocellular carcinoma: Correlation, mechanisms, therapeutic implications, and future perspectives

Hepatocellular carcinoma (HCC) is a highly heterogeneous and complex cancer influenced by both the tumor microenvironment and multi-level regulation of the nervous system. Increasing evidence highlights critical roles of the central nervous system (CNS) and peripheral nervous system (PNS) in modulating HCC progression. Psychological stress and emotional disturbances, representing CNS dysregulation, directly accelerate tumor growth, metastasis, and impair anti-tumor immunity in HCC. PNS involvement, particularly autonomic innervation, extensively reshapes the hepatic tumor microenvironment. Specifically, sympathetic activation promotes immune suppression, tumor cell proliferation, epithelial-mesenchymal transition (EMT), and cancer stemness via β-adrenergic signaling and hypoxia-inducible factor 1-alpha (HIF-1α) stabilization, whereas parasympathetic signals generally exert anti-inflammatory and tumor-suppressive effects mediated by acetylcholine. Neurotransmitters including epinephrine, norepinephrine, dopamine, serotonin, and acetylcholine precisely regulate critical pathways such as AKT/mTOR, ERK, and NF-κB, thereby driving malignant cell behaviors, immune evasion, and chemoresistance. Neuro-targeted pharmacological interventions (e.g., SSRIs, β-blockers, dopamine antagonists) and behavioral therapies have shown efficacy in preclinical studies, underscoring their therapeutic potential. Additionally, neural-associated biomarkers like NEDD9, CNTN1, and nerve growth factor (NGF) exhibit prognostic significance, supporting their future clinical application. By systematically integrating neuroscience with oncology, this review identifies innovative neural-based therapeutic strategies, highlights key mechanistic insights, and outlines promising directions for future research and personalized clinical management of HCC.

Functional Suppression of a Prolactinoma by a Dopamine-Secreting Paraganglioma

Prolactin-secreting pituitary adenomas are typically treated with dopamine agonists to inhibit prolactin secretion and reduce tumor size. Dopamine-secreting paragangliomas are rare neuroendocrine tumors of sympathetic and parasympathetic paraganglia and often do not provoke symptoms of catecholamine excess. Although overlapping genetic drivers have been described for paragangliomas and pituitary adenomas, biochemical crosstalk between coexisting tumors is underexplored. We describe the case of a 52-year-old male individual who presented with cerebrospinal fluid (CSF) rhinorrhea and was found to have an invasive, 4.2-cm pituitary mass with modestly elevated prolactin (130.9 ng/mL [130.9 µg/L], reference range [RR] 2-18 ng/mL [2-18 µg/L]). Additional imaging discovered a mediastinal mass suspicious for a thoracic paraganglioma. Biochemical screening demonstrated marked elevation of plasma and urinary dopamine. Following paraganglioma resection, dopamine levels normalized, but prolactin rose significantly (877.8 ng/mL [877.8 µg/L]), suggesting an endogenous dopamine agonist-like effect from the paraganglioma to suppress pituitary prolactin hypersecretion. Pituitary pathology was notable for a PIT1 (pituitary transcription factor-1)-lineage pituitary adenoma with absent immunohistochemical staining for prolactin. Genetic testing found a previously unreported germline SDHC variant of uncertain significance. In this case, we report a novel biologic signaling mechanism between 2 rare primary endocrine tumors and highlight challenges in their diagnosis and management.

Hypertensive retinopathy as the first manifestation of extra-adrenal paraganglioma

Paragangliomas are rare neuroendocrine tumors originating from paraganglionic cells in the autonomic nervous system and which are capable of secreting catecholamines and causing hypertensive crises. Although typically benign, they can exhibit aggressive features and present with varied clinical manifestations depending on location and catecholamine activity. Herein, we report an unusual case of a 28-year-old male who initially presented with bilateral grade IV hypertensive retinopathy, an uncommon initial manifestation of paraganglioma. Fundus examination revealed severe hypertensive retinopathy with exudative retinal detachment. Laboratory evaluation demonstrated markedly elevated plasma and urinary catecholamines and metanephrines. Imaging, including computed tomography (CT) and iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy, confirmed a highly vascularized mass near the left adrenal gland, consistent with extra-adrenal paraganglioma. The patient's hypertension was medically stabilized prior to successful surgical tumor resection. Postoperatively, blood pressure normalized without medication, and significant improvement was observed in retinal findings, including resolution of disc edema and macular exudates. This case highlights the importance of considering paraganglioma in the differential diagnosis of malignant hypertension with ocular involvement, even when typical systemic symptoms of catecholamine excess are absent. Prompt recognition and intervention can lead to favorable visual and systemic outcomes.

The clinical spectrum of adrenal ganglioneuromas extends from severe hypertension to an asymptomatic incidentaloma; two cases and mini review of literature

PURPOSE

Herein, we present two interesting cases of adrenal ganglioneuromas (AGNs), namely, (a) a giant AGN which caused a severe episode of hypertension during a therapeutic dilation and curettage for early pregnancy loss, and (b) a case of a composite clinically silent adrenal ganglioneuroma-pheochromocytoma. Furthermore, we conducted a mini literature review on AGNs. CASE 1: A 31-year-old female patient presented with a history of early pregnancy loss at 9 ½ weeks. She underwent a therapeutic dilation and curettage during which she developed hypertension (~ 210/120 mm Hg). She reported no history of arterial hypertension, flushing, or tachycardia and her medical history was unremarkable. Further work-up, revealed a large heterogeneous tumor with microcalcifications in the left adrenal gland. Endocrine work-up was negative for hormonal excess. Magnetic resonance angiography (MRA) of the abdomen showed that the tumor was 'surrounding and strangling' the left renal vessels and the inferior vena cava. The patient successfully underwent an open left adrenalectomy and nephrectomy. Histology revealed an adrenal mature ganglioneuroma with Schwannian stroma being dominant. Her postoperative course was uneventful and she remains recurrence-free 6 years after surgery. CASE 2: A 37-year-old male patient was admitted to the hospital because of abdominal pain and hematuria. Computer tomography identified a 4-cm right adrenal lesion. Due to elevated urinary metanephrines, he underwent laparoscopic right adrenalectomy after appropriate alpha-blockade preparation preoperatively. Histology was consistent with pheochromocytoma with a component of ganglioneuroma, thus, a composite pheochromocytoma. His post-operative course was excellent and he remains asymptomatic and recurrence-free 60 months post-operatively.

CONCLUSION

These are two challenging cases of (a) a giant non-secreting AGN presenting with severe hypertension due to renal vessel compression and (b) a clinically silent composite pheochromocytoma-ganglioneuroma presenting with abdominal pain and hematuria. The size in the first case and the concurrence with a pheochromocytoma but a clinically silent phenotype in the second case highlight the fact that AGNs can be diagnostic chameleons.

Imaging of Adrenal Masses

Adrenal lesions are common and require appropriate management when clinically relevant. The approach to the evaluation of an adrenal lesion is to exclude malignancy and hormone excess as these are associated with significant morbidity and mortality. Imaging of adrenal lesions primarily aims to identify features indicating benignity. Non-contrast CT is recommended as first-line imaging for adrenal lesions. Indeterminate lesions that require further characterization may proceed to adrenal protocol CT (with contrast) or MRI, with a trend in recent years towards increasing use of MRI. PET-CT may also be used to assess adrenal lesions in certain clinical scenarios. Clinical guidelines recommend that all adrenal incidentalomas require further dedicated imaging unless they are clearly benign on imaging. The imaging strategy of adrenal lesions depends upon a number of factors including patient history, nature of detection, imaging characteristics (size, heterogeneity, presence of intracellular lipid), and the presence or absence of hormone excess. Special considerations are given to pregnant patients, young patients < 40 years, and those with a history of an extra-adrenal malignancy. This review outlines the role of imaging for adrenal lesions, describes the various imaging options and investigation strategies, and highlights relevant imaging findings.

Single-cell chromosome and bulk transcriptome analysis as a diagnostic tool to differentiate between localized and metastatic pheochromocytoma and sympathetic paraganglioma

Approximately 10-20% of patients with pheochromocytoma or sympathetic paraganglioma (PPGL) develop metastatic disease, most often as metachronous lesions. Unfortunately, there is a lack of accurate biomarkers that can predict the biologic behavior of a PPGL at the initial diagnosis. We investigated tumor samples from patients with PPGL and a diagnosis of either localized or metastatic disease with synchronous or metachronous metastases and performed a comprehensive molecular analysis through application of single-cell whole-genome sequencing and bulk transcriptome analysis, including variant detection analysis of RNA sequences. We found that PPGL displayed complex karyotypes with recurrent aneuploidies and substantial cell-to-cell karyotype variability, indicating ongoing chromosomal instability (CIN) in both localized and metastatic tumors. Transcriptome analysis on the other hand revealed several differences between localized and metastatic PPGL including TNFα and TGFβ signaling in metastatic PPGL that were already detectable in primary tumor samples of initially non-metastatic-appearing PPGLs that developed metachronous metastases. Altogether our findings indicate that while localized and metastatic PPGL in general have comparable genomic landscapes, they do show transcriptional differences that are already detectable in primary tumor PPGL before development of metastases. This finding could provide an important tool for improvement of patient stratification at initial diagnosis.

SLC25A11, a Novel Gene Associated With Carney-Stratakis Syndrome

Background

Carney-Stratakis syndrome (CSS), a rare condition characterized by paragangliomas and/or pheochromocytomas and gastrointestinal stromal tumors (GIST), is caused by germline heterozygous pathogenic variants in the succinate dehydrogenase subunit genes (SDHB, SDHC, SDHD).

Methods

Histological, genetic, and functional analyses were conducted in a 59-year-old female with CSS (9 cm left pheochromocytoma, 4.8 cm paraganglioma, and 9.3 cm GIST). Whole-exome sequencing (WES) of germline DNA paired with tumor DNA was performed.

Results

WES identified a rare heterozygous germline variant (c.293G>A/p.Arg98His) in the mitochondrial 2-oxoglutarate/malate carrier gene (SLC25A11). This variant, located in a highly conserved residue of the SLC25A11 mitochondrial carrier domain, is predicted to be deleterious in silico (REVEL score = 0.81). WES of pheochromocytoma, paraganglioma, and GIST did not reveal somatic pathogenic variants in genes previously associated with these tumors. A significant reduction in SLC25A11 expression was observed in the tumors of this patient with the SLC25A11 c.293G>A variant (0.69 ± 0.003) compared to tumors from cluster 1 (1.39 ± 0.45; P = 0.0229) and cluster 2 (1.79 ± 0.71; P = .0154). Consistent with the mRNA findings, SLC25A11 protein levels were markedly reduced in the pheochromocytoma and paraganglioma compared to other tumors. Negative staining for 5-hydroxymethylcytosine in all 3 tumors suggests a DNA hypermethylation profile characteristic of cluster 1A, despite normal SDHB expression levels. However, genome-wide copy number variation analysis did not reveal any loss of heterozygosity at the SLC25A11 locus.

Conclusion

The loss of SLC25A11 expression in tumors, the absence of somatic drivers, and the hypermethylation status strongly support the role of SLC25A11 in CSS pathogenesis.

Intracystic catecholamine variations in cystic pheochromocytoma

PURPOSE

Approximately 20% of pheochromocytomas are cystic in nature. However, research on the correlation between catecholamine and metanephrine fractions in cystic fluid and peripheral blood is limited. This study investigated the relationship between catecholamine fractions and their metabolites in peripheral blood and cystic fluid.

METHODS

Five patients with pathologically diagnosed cystic pheochromocytomas were included in the analysis. Catecholamine fractions and their metabolites in the cystic fluid were measured. The relationship between phenylethanolamine N-methyltransferase (PNMT) expression in tumor tissues and catecholamine fractions of cystic fluid was also assessed.

RESULTS

The elevated patterns of catecholamine and metanephrine fractions in the cystic fluid were consistent with those observed in the peripheral blood of two patients. However, in two other patients. discordance was observed, with normetanephrine predominance in the peripheral blood despite adrenaline/metanephrine and noradrenaline/normetanephrine elevations in the cystic fluid. Immunohistochemical analysis revealed that PNMT expression in tumor tissues and the elevated pattern of catecholamine fractions in the peripheral blood were consistent in all patients, except for one patient with non-elevated peripheral blood catecholamines. However, in cystic fluid, the predominantly catecholamine fraction did not consistently align with PNMT expression.

CONCLUSION

In cystic pheochromocytoma, the elevation patterns of catecholamine fractions in cysts may not align with those in the peripheral blood and may differ relative to PNMT expression in tumor tissues.

Bilateral carotid body tumor management: tips, tricks, strategies, and problems

PURPOSE OF REVIEW

Carotid body tumors (CBTs) are rare neuroendocrine tumors with an annual incidence of 1 : 30 000. Bilateral carotid body tumors (BCBTs) account for 3-5% of all CBTs and are more frequently linked to familial syndromes and potential malignancy. BCBT management is still not universally standardized and depends on multiple factors, including patient's age, risk of malignancy, location, growth rate, size, and related Shamblin and Mehanna classifications.

RECENT FINDINGS

Options of treatment include active surveillance, external beam radiation, and surgery. Surgery is the first-choice treatment, but it may not always be performed especially in elderly patients. Simultaneous BCBT resection is not suggested due to high intra-operative and postoperative risks. The decision to operate on the larger or smaller tumor first is still debated. Whenever feasible, treatment of the larger tumor first to reduce the tumor burden should be preferred but with higher risks of neurovascular injury. Conversely, starting with the smaller tumor first offers a lower risk at initial surgery but may complicate the management of the larger tumor later.

SUMMARY

Surgery for BCBTs, whenever feasible, remains the most indicated treatment but poses a significant risk of neurovascular complications. Resection of the larger, often more symptomatic, and potentially problematic or malignant tumor, reduces the overall disease burden and mitigates risks of rapid progression but involves a higher immediate complication hazard. Multidisciplinary evaluation is essential for balancing surgical risks and long-term outcomes, prioritizing neurovascular preservation and reducing morbidity.

Primary Intraosseous Paraganglioma of the Femoral Neck: A Case Report and Review of the Literature

CASE

An 88-year-old woman presented with worsening right hip pain over 2 years. Radiographs were unremarkable, but magnetic resonance imaging identified a femoral neck lesion. A computed tomography-guided biopsy revealed a zellballen pattern of cells positive for chromogranin and synaptophysin. Further workup, including a metaiodobenzylguanidine scan confirmed focal uptake at the right femoral neck. After multidisciplinary discussion, and shared decision-making with the patient, conservative management was chosen.

CONCLUSION

Primary intraosseous paragangliomas are rare, with this case representing only the second reported in femur and third in the appendicular skeleton. It underscores the importance of a multimodal diagnostic approach, individualized treatment plans, and multidisciplinary collaboration.

A rare case of a composite phaeochromocytoma-ganglioneuroma in Australia

Composite phaeochromocytomas (CP) of the adrenal medulla are rare neuroendocrine tumours, comprising phaeochromocytoma and neurogenic components. They may present heterogeneously like ordinary phaeochromocytomas and are ideally managed surgically with a multidisciplinary approach. This report describes the case of a CP in Australia, which was cured by a surgical team in an unplanned two-staged left adrenalectomy over a 20-year period.

Immunohistochemical and histomorphologic characterization of canine neoplasms of the disseminated neuroendocrine system

Canine neoplasms of the diffuse neuroendocrine system are an enigmatic and heterogeneous group of neoplasms with a wide spectrum of immunohistochemical properties and morphologic features. Through the utilization of tissue microarrays, 82 canine neoplasms of the disseminated neuroendocrine system from 16 different anatomic locations were evaluated. The prototypical canine neoplasm of the disseminated neuroendocrine system was composed of rounded polygonal neoplastic cells arranged in packets supported by delicate fibrovascular stroma. Neoplastic cells typically had moderate quantities of pale eosinophilic cytoplasm stippled by numerous fine argyrophilic granules, round nuclei with finely stippled chromatin, and inconspicuous nucleoli. Immunohistochemical assays utilized in this study included chromogranin A, neuron-specific enolase (NSE), microtubule-associated protein 2 (MAP2), pan-cytokeratin, oligodendrocyte transcription factor 2 (OLIG2), protein gene product 9.5 (PGP9.5), vimentin, synaptophysin, neuronal nuclei (NeuN), S100, SRY-related HMG-box 10 (SOX10), glial fibrillary acidic protein (GFAP), insulinoma-associated protein 1 (INSM1), CD56, and antigen Kiel 67 (Ki67). The 4 immunohistochemical assays that were positive in over 50% of cases included PGP9.5 (77/82, 94%), NSE (68/82, 83%), synaptophysin (59/82, 72%), and chromogranin A (56/82, 69%). In 81/82 (99%) cases, neoplastic cells immunolabeled with at least 1 of these 4 assays, and thus, these 4 immunohistochemical assays are deemed most useful when attempting to substantiate that a neoplasm is of neuroendocrine origin.

Pheochromocytomas and Paragangliomas-Current Management

Pheochromocytomas and paragangliomas (PPGLs) are infrequent neuroendocrine hypervascular neoplasms arising within different sites of the paraganglion system. They are divided into sympathetic (including pheochromocytomas and extraadrenal paragangliomas) and parasympathetic extraadrenal tumors. These tumors are usually not malignant and grow slowly; about 90% of them are found in the adrenal paraganglia (pheochromocytomas). Extraadrenal tumors are most frequently located in the abdominal cavity (85%), followed by the thoracic cavity (12%), and head and neck (3%). About 25% of PPGLs are related to germline mutations, which are risk factors for multifocal and metastatic disease. In PPGL diagnostics, laboratory, biochemical, and imaging (anatomical and functional) examinations are used. Surgery is the standard management choice for locoregional disease. For patients who are not candidates for surgery and who have stable, not-growing, or slow-growing tumors, active observation or other less invasive techniques (i.e., stereotactic surgery, hypofractionated stereotactic radiotherapy) are considered. In metastatic disease, systemic therapies (tyrosine kinase inhibitors [TKIs], mTORC1 inhibitor everolimus, immunotherapy, cold somatostatin analogs [biotherapy], and radioligand therapy) are used. The prognosis for PPGLs is quite good, and the 5-year survival rate is >90%. The goal of this paper is to review knowledge on the etiopathogenesis, current diagnostics, and therapy for PPGL patients. Our paper is particularly focused on the current management of PPGLs.

Potential Risks of Minoxidil in Pheochromocytoma and Paraganglioma: A Commentary on Safety Concerns and Mechanisms

Pheochromocytoma and paraganglioma are neuroendocrine tumours characterised by excessive catecholamine release. Minoxidil, a potent vasodilator commonly used for hypertension and androgenetic alopecia, may exacerbate cardiovascular complications associated with pheochromocytoma due to its mechanisms-of-action. This commentary aims to elucidate the potential risks and safety concerns associated with the use of minoxidil in patients with pheochromocytoma. Here, we discuss the need for careful prescribing practices when considering minoxidil in pheochromocytoma-associated hypertension and the potential problems that minoxidil use may cause in pheochromocytoma patients.

Preoperative Management of Catecholamine-Producing Pheochromocytomas and Paragangliomas-Results From a DELPHI Process

Context

European and German consensus guidelines advocate preoperative therapy with α-adrenoreceptor antagonists in symptomatic patients with catecholamine-producing pheochromocytomas and paragangliomas (PPGLs) to avoid hypertensive crisis during adrenalectomy. This practice has been questioned recently.

Objective

This work aimed to assess current preoperative management of PPGLs across disciplines.

Methods

The study was conducted from November 2023 to February 2024 using the Delphi technique. Two consecutive surveys were conceived by a steering group and 46 experts were consulted using REDCap web application (response: 74%).

Results

There was general agreement about diagnostic tools and indication for adrenalectomy. In contrast, 20% of the panelists routinely administered α-adrenoreceptor antagonists to all patients, 50% only in case of symptoms, and about one-third of experts abandoned preoperative α-adrenoreceptor blockade. The prevention of anticipated intraoperative hypertensive crisis and cardiovascular complications (75%) as well as medicolegal considerations (25%) were the main motivations. Despite availability of short-acting α-adrenoreceptor antagonists, most experts (63%) continued to use phenoxybenzamine. Half of the experts preferred pretreatment in an outpatient setting, 13% routinely treated in the hospital, and 37% combined outpatient and inpatient treatment. Intraoperatively, urapidil and nitroprusside natrium were mainly used for blood pressure control. Postoperatively, around 60% of the experts routinely admitted patients to an intensive care or intermediate care unit.

Conclusion

Current guideline recommendations for preoperative treatment with α-adrenoreceptor antagonists in patients with PPGLs are generally adopted by treating teams but current practice is very heterogeneous even among expert centers. With the improvement of surgical techniques and intraoperative management, a more individualized approach may be considered.

Prognostic Significance of Preoperative NLR or PLR and PASS Score Combinations in Pheochromocytoma and Paraganglioma

CONTEXT

Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have recently emerged in assessing pheochromocytomas and paragangliomas (PPGLs). However, their combined use with PASS scale has not yet been explored.

OBJECTIVE

Our goal was to investigate the prognostic values of NLR and PLR and incorporate the PASS score into our analysis.

METHODS

Data from 74 histologically confirmed pheochromocytomas/paragangliomas across two centres were assessed. Poor prognosis was characterised by the presence of metastasis or disease-specific mortality. Clinical characteristics such as age, gender, primary tumour size and location, and urinary metanephrine and normetanephrine levels, alongside NLR, PLR, and the PASS score as prognostic markers, were analysed. The prognostic value of the PASS score combined with NLR or PLR was evaluated using Receiver Operating Characteristic Curve (ROC), univariate, and multivariate regression analyses.

RESULTS

Sixty-four patients with better prognosis and 10 patients with poor prognosis were included in the analysis, with mean PASS scores of 4 and 9, respectively. Poor prognosis was significantly higher in patients with NLR Á 3.43 (Area Under Curve(AUC) = 0.761; 70% sensitivity, 82.8% specificity, 38.9% PPV and 94.7% NPV) and with PLR > 193.12 (AUC = 0.738; 70% sensitivity, 76.2% specificity, 30% PPV and 94% NPV). The PASS and preoperative NLR or PLR combination predicted poor prognosis significantly in the multivariate models (OR: 125; 95% CI: 6.25-∞; p = 0.001 for PASS ≥ 6 and NLR > 3.43 and OR: 28.57; 95% CI: 3-250; p = 0.003 for PASS ≥ 6 and PLR > 193.12).

CONCLUSION

As the roles of NLR and PLR in prediction of prognosis is gaining recognition, combining these with PASS score may improve preoperative stratification of prognosis and management of patients.

A case of bladder paraganglioma completely resected by transurethral endoscopic en-bloc resection of bladder tumor

Introduction

En-bloc resection of bladder tumors is performed for bladder cancer with the goal of achieving precise tumor resection and providing an informative pathology specimen. We report the first case of a safely resected bladder paraganglioma by en-bloc resection.

Case presentation

A 57-year-old woman presented with an incidental bladder tumor detected on computed tomography. Cystoscopy revealed a 10 mm submucosal tumor. Magnetic resonance imaging indicated a suspected bladder paraganglioma, whereas endocrinological tests showed no abnormalities. The tumor was completely resected in one piece without an intraoperative increase in blood pressure or bladder perforation. Pathological examination revealed a bladder paraganglioma with negative surgical margins. No evidence of recurrence was observed at 9 months follow-up.

Conclusion

En-bloc resection of bladder tumors may be a useful approach for selected cases of bladder paragangliomas, potentially decreasing the risk of intraoperative blood pressure fluctuations and ensuring complete tumor resection.

Clinical presentation of pheochromocytoma and screening recommendations

Pheochromocytomas are neuroendocrine tumors that derive from sympathetic adrenomedullary chromaffin tissue and produce catecholamines. Due to the excess release of catecholamines, they can produce arterial hypertension, tachycardia, sweating, headache and a large number of other clinical manifestations secondary to the stimulation of α and β adrenoreceptors. Screening for pheochromocytoma is recommended in patients with paroxysmal, resistant or early-onset arterial hypertension, in cases with symptoms suggestive of catecholamine hypersecretion, patients with hereditary syndromes associated with pheochromocytomas, diabetes mellitus of atypical presentation and in adrenal incidentalomas with radiological characteristics not typical of adenoma (with > 10 Hounsfield Units on non-contrast CT). In this article we present an exhaustive review of the clinical data and complications that can be associated with pheochromocytomas, and we summarize the main indications for pheochromocytoma screening.

Incidental left paraaortic mass in a patient with gall bladder adenocarcinoma: A diagnostic challenge

Incidental adrenal masses are frequently detected due to the extensive use of cross-sectional imaging, with about 3% to 7% of adults estimated to have them. Paragangliomas and pheochromocytomas (PPGL), rare tumors originating from paraganglia tissues, including the adrenal medulla, continue to be imaging mimics, necessitating a multimodal approach for accurate diagnosis. We report a case of 72-years male presenting with intermittent pain abdomen for the past 1 year. Preliminary imaging by ultrasound revealed a suspicious gall bladder polypoidal lesion along with choledochal cyst for which further characterization was done with both CT and MRI. On imaging besides defining the findings seen in USG, we encountered a large heterogeneously enhancing possible left adrenal incidentaloma. A homogeneously hyper enhancing lesion along the paraganglia distribution, with no evidence of washout and a high T2 signal, is a hallmark imaging characteristic of pheochromocytomas and paragangliomas. However, around 35% of atypical lesions, often altered by degenerative changes, deviate from these typical imaging patterns, presenting a diagnostic dilemma. Histopathological analysis, including immunohistochemistry, biochemical testing, and functional imaging, can offer valuable insights to help diagnose and aid in predicting prognosis.

Why do patients with pheochromocytomas/paragangliomas exhibit significantly inconsistent elevation of catecholamines and their metabolites? a large Chinese cohort study

OBJECTIVES

Inconsistent elevation of catecholamines (CAs) and metanephrines (MNs) was observed in pheochromocytomas/paragangliomas (PPGLs). This study aimed to explore its potential causes and report the diagnostic efficacy of MNs and CAs in a large Chinese PPGL cohort.

METHODS

Clinical data and results of hormone tests were retrospectively collected. The sensitivity of plasma MNs and 24h-urinary CAs was analyzed. Clinical characteristics were compared between patients with positive and negative biochemical results, and among those with inconsistent elevation of MNs and CAs.

RESULTS

Seven hundred and three patients were included, with a median onset age of 41.0 years. Plasma MNs (93% ~ 99%) showed prior diagnostic sensitivity to 24h-urinary CAs (74% ~ 89%). Patients with negative biochemical results presented as a smaller tumor (1.7 cm vs. 4.3 cm, P = 0.001), a higher proportion of normal blood pressure (60.0% vs. 20.5%, P = 0.002) and negative 131I-meta-iodobenzylguanidine (131I-MIBG) imaging (55.6% vs. 17.3%, P = 0.012). An earlier age of onset (40.0 vs. 41.0 vs. 44.5 years, P = 0.025), a higher proportion of paroxysmal hypertension (36.5% vs. 29.2% vs. 32.2%, P = 0.005) and the Epinephrine secretion type (79.3% vs. 37.7% vs. 48.0%, P < 0.001) were found in patients with the ratio of MNs/CAs elevation multiples <0.5 than those with the ratio between 0.5 and 2 or >2.

CONCLUSIONS

Plasma MNs exhibited a superior sensitivity than 24-h-urinary CAs in the Chinese PPGL diagnosis. Patients with a small tumor, normal blood pressure and negative 131I-MIBG imaging were prone to express negative biochemical levels. Additionally, an obvious elevation of 24-h-urinary CAs than plasma MNs was correlated to paroxysmal hypertension and the Epinephrine type.

Molecular Signatures of Cancer Stemness Characterize the Correlations with Prognosis and Immune Landscape and Predict Risk Stratification in Pheochromocytomas and Paragangliomas

BACKGROUND

Pheochromocytoma and paragangliomas (PPGLs) caused refractory hypertension in clinics. The sustained risk of local or metastatic recurrences or new tumor development prompted more research on diagnosis, prognosis prediction, and immunotherapy.

METHOD

The tumor stemness is closely related to the heterogeneous growth of tumor, metastasis, and drug-resistance, and mRNA expression-based stemness indices (mRNAsi) could reflect tumor stemness. This was calculated based on OCLR machine learning algorithm and PPGLs patients' TCGA RNAseq data. The relationship between clinical, molecular, and tumor microenvironment (TME) features and tumor stemness was analyzed through the hub genes that best captured the stem cell characteristics of PPGLs using weighted gene co-expression network analysis (WGCNA), Cox, and LASSO regression analysis.

RESULTS

Our study found that metastatic PPGLs had higher mRNAsi scores, suggesting the degree of tumor stemness could affect metastasis and progression. HRAS, CSDE1, NF1, RET, and VHL-mutant subtypes displayed significant difference in stemness expression. Patients were divided into stemness high-score and low-score subtypes. High-score PPGLs displayed the more unfavorable prognosis compared with low-score, associated with their immune-suppressive features, manifested as low macrophages M1 infiltration and downregulated expression of immune checkpoints. Furthermore, from the viewpoint of stemness features, we established a reliable prognostic for PPGLs, which has the highest AUC value (0.908) in the field so far. And this could stratify PPGLs patients into high-risk and low-risk subtypes, showing the significant differences in prognosis, underlying mechanisms correlated with specific molecular alterations, biological processes activation, and TME. Notably, high immune infiltration and tumor neoantigen in low-risk patients and further resulted in more responsive to immunotherapy.

CONCLUSION

We indicated that tumor stemness could act as the potential biomarker for metastasis or prognosis of PPGLs, and integrated multi-data sources, analyzed valuable stemness-related genes, developed and verified a novel stemness scoring system to predict prognosis and guide the choice of treatment strategies.

Approach to the Paediatric Patient With Suspected Pheochromocytoma or Paraganglioma Versus Neuroblastoma

Catecholamine-producing tumors of childhood include neuroblastic tumors, phaeochromocytoma, and paraganglioma (PPGL). PPGL and neuroblastic tumors can arise in similar anatomical locations and clinical presentations can overlap, resulting in diagnostic challenges. Distinguishing between these tumor types is critical as management and long-term surveillance strategies differ depending on the diagnosis. Herein we describe 2 clinical cases and illustrate key considerations in the diagnostic workup of a neuroblastoma vs PPGL for patients presenting with adrenal, pelvic, and retroperitoneal masses in childhood.

Role of radiologists in the diagnosis and management of adrenal disorders

This study aimed to focus on the role of radiologists in the diagnosis and management of adrenal lesions, particularly primary aldosteronism (PA) and secondary hypertension. As hypertension affects more than one-third of the population in Japan, identifying secondary causes such as PA and adrenal lesions is crucial. Establishing a radiological differential diagnosis of adrenal lesions using advanced imaging techniques, such as computed tomography and magnetic resonance imaging, is crucial. Knowledge of the imaging findings of various benign and malignant adrenal lesions, such as adrenocortical adenomas, cortisol-producing lesions, pheochromocytomas, adrenocortical carcinoma, malignant lymphoma, and metastatic tumors, is necessary. Adrenal venous sampling (AVS) plays a crucial role in accurately localizing aldosterone hypersecretion in PA, especially when imaging fails to provide a clear diagnosis. This paper details the technical aspects of AVS, emphasizing catheterization techniques, anatomical considerations, and the importance of preprocedural imaging for successful sampling. Furthermore, we explore segmental adrenal venous sampling (SAVS), a more refined technique that samples specific adrenal tributary veins, offering enhanced diagnostic accuracy, particularly for microadenomas or challenging cases that may be missed with conventional AVS. The methodology for performing SAVS, along with the interpretation criteria for successful sampling and lateralization, is also outlined. Furthermore, radiologists have initiated treatments for unilateral PA, such as radiofrequency ablation, and play an integral role in the management of adrenal lesions. Collaborative approaches across clinical departments are required to enhance patient management in medical care involving the adrenal gland.

[Paragangliomas - Essentials for the ENT Doctor]

Paragangliomas of the head and neck area should be detected early and diagnosed in their complexity at specialized centers, treated and, in the presence of paraganglioma syndrome, cared for for life. The continuing education article focuses in an abridged form on the most important basics of a complex clinical picture and deals with both sporadic head and neck paragangliomas and hereditary paraganglioma syndromes. It contains concise recommendations regarding genetic testing, the diagnosis of multicentric tumors, the multidisciplinary treatment approach and the need for lifelong monitoring.

Urinary Dopamine Levels Can Predict the Avidity of Post-Therapy [131I]MIBG Scintigraphy in Unresectable or Metastatic Pheochromocytomas and Paragangliomas: A Preliminary Clinical Study

Background/Objectives: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors that produce catecholamines. Unresectable or metastatic PPGLs are treated with [131I]metaiodobenzylguanidine (MIBG), but MIBG avidity is often heterogeneous. Identifying predictive factors for non-avid lesions on scintigraphy is clinically important. The primary objective of this study was to investigate the relationship between MIBG avidity and catecholamine secretion patterns in patients with unresectable or metastatic PPGLs. Methods: This retrospective study included 27 patients treated with [131I]MIBG for unresectable/metastatic PPGLs between 2001 and 2024. Patients received a single intravenous dose of [131I]MIBG (5.5-7.4 GBq), with post-therapy scintigraphy performed 3-7 days later. Non-avid lesions were assessed by imaging and confirmed using CT, MRI, and FDG-PET. Clinical factors, including age, sex, prior treatments, metastasis sites, and urine catecholamines, were evaluated using univariate logistic analysis. Predictive factors were assessed via receiver operating characteristic curves. Results: Non-avid lesions were found in nine patients (33.3%). These patients were younger (median age 38 vs. 62.5 years) and had higher urine dopamine levels (median 1510 vs. 779 μg/day) than those without non-avid lesions. Younger age (odds ratio: 0.892, p < 0.01) and higher urinary dopamine levels (odds ratio: 1.003, p < 0.01) were significantly associated with non-avid lesions. All patients > 45 years with urinary dopamine < 1190 μg/day had no non-avid lesions, whereas patients < 45 years with urinary dopamine > 1190 μg/day had non-avid lesions. Conclusions: Age and urinary dopamine levels may predict non-avid lesions in unresectable/metastatic PPGLs, aiding treatment decisions for [131I]MIBG therapy. This article is a revised and expanded version of a paper entitled "Urine dopamine level and age can predict non-avid lesion on scintigraphy after I-131 MIBG treatment for unresectable/metastatic PPGL", which was presented at SNMMI 2024, Toronto, from 8 June to 11 June 2024.

Positron Emission Tomography Imaging of Pheochromocytoma and Paraganglioma-18F-FDOPA vs Somatostatin Analogues

CONTEXT

Functional imaging with positron emission tomography (PET) scans is an essential part of the diagnostic workup for pheochromocytoma and paraganglioma (PPGL). The purpose of this review is to (1) provide a brief overview of functional imaging for PPGL, (2) summarize selected present and older guideline and review recommendations, and (3) conduct a literature review on the diagnostic performance of the most used PET tracers for PPGL.

EVIDENCE ACQUISITION

We conducted a systematic literature search in PubMed from January 2004 to August 2024 with the search string ("Pheochromocytoma" OR "Paraganglioma") AND ("Positron Emission Tomography" OR "Radionuclide Imaging" OR ("PET" AND ("FDG" OR "DOTATOC" OR "DOTANOC" OR "DOTATATE" OR "DOPA" OR "FDOPA"))). Studies involving PET scans of at least 20 individuals with PPGL or at least 5 individuals in a rare, well-defined subgroup of PPGL (eg, sympathetic or head-neck paragangliomas and specific pathogenic variants) were included.

EVIDENCE SYNTHESIS

Seventy studies were identified of which 21 were head-to-head comparisons of at least 2 different PET tracers [18F-fluorodihydroxyphenylalanine, fluorodihydroxyphenylalanine positron emission tomography (18F-FDOPA), 68Ga-DOTA-conjugated somatostatin analogues, 68Ga-DOTA-conjugated somatostatin analogue positron emission tomography (68Ga-SSA), and 18F-fluorodeoxyglucose]. 18F-FDOPA had higher sensitivity for pheochromocytoma compared to 68Ga-SSA and equal sensitivity for metastatic pheochromocytoma. 18F-FDOPA and 68Ga-SSA had similar sensitivity for primary non-succinate dehydrogenase subunits (SDHx) sympathetic and head-neck paraganglioma. However, 68Ga-SSA had higher sensitivity for metastatic sympathetic and head-neck paraganglioma and for SDHx-related paraganglioma.

CONCLUSION

18F-FDOPA and 68Ga-SSA PET are both sensitive for localizing PPGL. However, 18F-FDOPA is the most sensitive for detecting pheochromocytoma, while 68Ga-SSA is superior to 18F-FDOPA for metastatic sympathetic and head-neck paraganglioma and SDHx-related paraganglioma.

Comparative evaluation of ACetic - MEthanol high salt dissociation approach for single-cell transcriptomics of frozen human tissues

Current dissociation methods for solid tissues in scRNA-seq studies do not guarantee intact single-cell isolation, especially for sensitive and complex human endocrine tissues. Most studies rely on enzymatic dissociation of fresh samples or nuclei isolation from frozen samples. Dissociating whole intact cells from fresh-frozen samples, commonly collected by biobanks, remains a challenge. Here, we utilized the acetic-methanol dissociation approach (ACME) to capture transcriptional profiles of individual cells from fresh-frozen tissue samples. This method combines acetic acid-based dissociation and methanol-based fixation. In our study, we optimized this approach for human endocrine tissue samples for the first time. We incorporated a high-salt washing buffer instead of the standard PBS to stabilize RNA and prevent RNases reactivation during rehydration. We have designated this optimized protocol as ACME HS (ACetic acid-MEthanol High Salt). This technique aims to preserve cell morphology and RNA integrity, minimizing transcriptome changes and providing a more accurate representation of mature mRNA. We compared the ability of enzymatic, ACME HS, and nuclei isolation methods to preserve major cell types, gene expression, and standard quality parameters across 41 tissue samples. Our results demonstrated that ACME HS effectively dissociates and fixes cells, preserving cell morphology and high RNA integrity. This makes ACME HS a valuable alternative for scRNA-seq protocols involving challenging tissues where obtaining a live cell suspension is difficult or disruptive.

Impact of sex hormones on pheochromocytomas, paragangliomas, and gastroenteropancreatic neuroendocrine tumors

OBJECTIVE

The effects of sex hormones remain largely unexplored in pheochromocytomas and paragangliomas (PPGLs) and gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

METHODS

We evaluated the effects of estradiol, progesterone, Dehydroepiandrosterone sulfate (DHEAS), and testosterone on human patient-derived PPGL/GEP-NET primary culture cell viability (n = 38/n = 12), performed next-generation sequencing and immunohistochemical hormone receptor analysis in patient-derived PPGL tumor tissues (n = 36).

RESULTS

In PPGLs, estradiol and progesterone (1 µm) demonstrated overall significant antitumor effects with the strongest efficacy in PPGLs with NF1 (cluster 2) pathogenic variants. Estrogen receptor alpha (ERα) positivity was detected in 11/36 PPGLs, including 4/4 head-and-neck paragangliomas (HNPGLs). ERα-positive tumors responded with a significant cell viability decrease to estradiol. DHEAS and testosterone (1 µm) displayed no effects, but higher doses of testosterone (10 µm) demonstrated significant antitumor effects, including a pheochromocytoma lung metastasis with strong androgen receptor positivity (30%). Driven by the antitumor effects of estrogen, we evaluated G-protein-coupled estrogen receptor (GPER) agonist G-1 as a potential therapeutic option for PPGLs and found strong significant antitumor potential, with the strongest efficacy in tumors with NF1 pathogenic variants. Moreover, we detected sex-related differences-tumors from male patients showed significantly stronger responsivity to G-1 compared with tumors from female patients. In GEP-NETs, sex hormones showed overall no effects, especially no tumor growth-promoting effects.

CONCLUSION

We provide novel data on the effects of elevated sex hormone levels, potentially seen during pregnancy or hormone replacement therapy, on PPGL/GEP-NET tumor growth. G-1 might offer a novel therapeutic approach for some PPGLs depending on patient's sex and the individual tumor's genetic/molecular background. All HNPGLs showed ERα positivity.

Head and neck paraganglioma in Pacak-Zhuang syndrome

BACKGROUND

Head and neck paragangliomas (HNPGLs) are typically slow-growing, hormonally inactive tumors of parasympathetic paraganglia. Inactivation of prolyl-hydroxylase domain-containing 2 protein causing indirect gain-of-function of hypoxia-inducible factor-2α (HIF-2α), encoded by EPAS1, was recently shown to cause carotid body hyperplasia. We previously described a syndrome with multiple sympathetic paragangliomas caused by direct gain-of-function variants in EPAS1 (Pacak-Zhuang syndrome, PZS) and developed a corresponding mouse model.

METHODS

We evaluated a cohort of patients with PZS (n = 9) for HNPGL by positron emission tomography, magnetic resonance imaging, and computed tomography and measured carotid body size compared to literature reference values. Resected tumors were evaluated by histologic sectioning and staining. We evaluated the corresponding mouse model at multiple developmental stages (P8 and adult) for lesions of the head and neck by high resolution ex vivo imaging and performed immunohistochemical staining on histologic sections of the identified lesions.

RESULTS

hree patients had imaging consistent with HNPGL, one of which warranted resection and was confirmed on histology. Three additional patients had carotid body enlargement (Z-score > 2.0), and 3 had carotid artery malformations. We found that 9 of 10 adult variant mice had carotid body tumors and 6 of 8 had a paraganglioma on the cranio-caval vein, the murine homologue of the superior vena cava; these were also found in 4 of 5 variant mice at post-natal day 8. These tumors and the one resected from a patient were positive for tyrosine hydroxylase, synaptophysin, and chromogranin A. Brown fat in a resected patient tumor carried the EPAS1 pathogenic variant.

CONCLUSIONS

These findings (1) suggest HNPGL as a feature of PZS and (2) show that these pathogenic variants are sufficient to cause the development of these tumors, which we believe represents a continuous spectrum of disease starting from hyperplasia.

Update on the diagnosis of the pheochromocytoma

Pheochromocytoma is a rare neuroendocrine tumour that develops from chromaffin cells in the adrenal medulla and is characterised by the excessive production of catecholamines and their metabolites. Diagnostic confirmation is performed by detecting elevated levels of catecholamines and/or their metabolites in plasma or 24-h urine. In the case of moderate elevations of normetanephrine, the clonidine suppression test may be useful to differentiate between endogenous hypersecretion and false positive results. Once the biochemical diagnosis is performed, the tumour localisation is carried out using imaging techniques and sometimes with nuclear medicine imaging tests. Furthermore, in all patients with pheochromocytomas it is recommended to perform a genetic study to identify hereditary disorders that may be present in more than 30% of cases and to perform a cardiological evaluation to rule out the presence of cardiovascular involvement secondary to the catecholamine hypersecretion.

Robotic-assisted excision of left para-aortic paraganglioma: a novel approach

Paragangliomas, a type of extra-adrenal tumour, albeit rare, are dangerous due to their high metastatic potential and risk of hypertensive crisis from massive catecholamine release. It typically presents with sympathetic overdrive symptoms such as diaphoresis, headache, and palpitation, accompanied by substantially high plasma metanephrines level and mass on contrasted computed tomography abdomen and pelvis, whilst some are found incidentally. In this report, we discuss a case of an extra-adrenal lesion located near susceptible major structures with extensive vascularisation, in a patient with near-death experience. Complete excision of the pulsatile mass with minimal bleeding and no complications, was made possible utilizing the da Vinci Robotic System. Robotic surgery, being a part of a multidisciplinary approach, leads to better patient outcomes and shorter hospitalisations. Moreover, it offers enhanced dexterity and improved depth perception compared to conventional methods. However, further studies are needed to validate its application in standard practice.

Pheochromocytoma in MEN2

Pheochromocytomas (PCs) are rare neuroendocrine tumors found in 20-50% of MEN2 patients. MEN2-related PCs are more often bilateral, identified at a younger age and have a low metastatic potential. They secrete epinephrine as the predominant catecholamine, along with its metabolite metanephrine, and lesser amounts of norepinephrine and normetanephrine. The advent of molecular diagnostic tools has enhanced the identification and stratification of these tumors, revealing a strong genotype-phenotype correlation which is crucial for screening and managing patients. Evaluation involves a combination of structural (CT/MRI) and functional imaging. MIBG remains helpful for PC assessment but novel PET ligands (18F-DOPA, 68Ga-DOTATATE, 18F-FDG) aid in the detection of extra-adrenal paragangliomas, recurrence, and metastatic disease. The treatment paradigm has shifted toward personalized medicine, incorporating genetic insights to tailor interventions, particularly surgical approaches and novel therapeutics such as radiolabeling of somatostatin analogs with lutetium and tyrosine kinase inhibitors.

Personalized management for phaeochromocytomas and paragangliomas in Latin America: A genetic perspective

Phaeochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors with clinical heterogeneity and a high association with hereditary disease, affecting approximately 30 % of the cases. Differences in the presentation and genetic etiologies of PPGLs have been demonstrated between Chinese and European patients. The frequency of germline genetic diagnosis was remarkably higher in Brazilian patients (∼50 %) compared with other cohorts (Chinese 21 %, European 31 %, and The Cancer Genome Atlas Program cohort 27 %). Interestingly, germline SDHB genetic defects were also more prevalent in Brazilian patients (17 %) with PPGLs when compared with other cohorts (3-9 %). The SDHB exon 1 deletion was responsible for approximately 50 % of the SDHB pathogenic/likely pathogenic variants in Brazilian patients with PPGLs due to a founder effect. The germline SDHB exon 1 deletion represents ∼10 % of the germline drivers in Brazilian patients (and possibly in Latin America). Therefore, a single diagnostic PCR for the SDHB exon 1 deletion might be very useful in clinical practice for genetic testing and counseling of patients with PPGLs in Latin America.

Overview of recent guidelines and consensus statements on initial screening and management of phaeochromocytoma and paraganglioma in SDHx pathogenic variant carriers and patients

Phaeochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumours with a strong genetic predisposition, involving over 20 genes and with germline pathogenic variants identified in 40 % of cases. The succinate dehydrogenase (SDHx) genes are the most commonly implicated in hereditary PPGLs, accounting for 20 % of cases, and present unique diagnostic and treatment challenges due to their potential for multiple, recurrent, and aggressive manifestations, often necessitating lifelong follow-up. Over the past two decades, advances in biochemical and imaging assessments, management, and follow-up protocols have significantly improved care for both adult and paediatric patients. These advances include next-generation sequencing, new biochemical tests, cluster-specific functional imaging, and improved surgical and radiotherapy techniques, such as stereotactic surgery and peptide receptor radionuclide therapy (PRRT). International consensus guidelines have been developed to standardise the management of patients with SDHx pathogenic variants, emphasising multidisciplinary approaches and frequent tumour board discussions. These guidelines, summarised below, cover recommendations for initial genetic testing, tumour screening, follow-up care, and management of patients and asymptomatic carriers.

Current views on paediatric phaeochromocytoma and paraganglioma with a focus on newest guidelines

Phaeochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumours which arise from chromaffin cells of the adrenal medulla or extra-adrenal autonomic ganglia. PPGL most commonly present in adulthood but can arise in childhood and adolescence with an estimated annual incidence of 0.5 cases per million children per year. There have been significant advances in the diagnosis and management of PPGL over the past 2-3 decades based largely on the study of adult patients. These advances in clinical knowledge can be applied to paediatric patients but like other cancers, paediatric PPGL must be viewed as a distinct subset with their own specific challenges and opportunities for improved clinical care. This review article provides an overview on the diagnosis and management of PPGL in children focusing on recent international guidance.

Progress in surgical approaches and outcomes of patients with pheochromocytoma and paraganglioma

Significant advances have been made in the past few decades in surgical management and outcomes of patients with pheochromocytoma and paraganglioma. Improvements in preoperative hypertensive control with the implementation of alpha- and beta-adrenergic blockade has resulted in better intra-operative blood pressure control and less incidence of hypertensive crises, which had been a large source of morbidity in the past. Emphasis on anesthesia and surgical team communication has also assisted in minimizing intraoperative hypertensive events at critical points of the operation. Shifting away from open resection, the now standard-of-care laparoscopic and minimally invasive adrenalectomy offers less pain, shorter hospitalizations, and quicker recoveries. Patient underlying germline mutations can guide the timing, approach, and extent of surgery. Postoperative outcomes have significantly improved with recent advancements in perioperative care in addition to regimented biochemical and radiographic surveillance. Here, we highlight the recent advancements in surgical approaches and outcomes for patients with pheochromocytoma and paraganglioma.

Systemic therapy for patients with metastatic pheochromocytoma and paraganglioma

Pheochromocytomas and paragangliomas are rare neuroendocrine tumors derived from the paraganglia. These tumors frequently secrete excessive amounts of catecholamines leading to cardiovascular and gastrointestinal complications. While all pheochromocytomas and paragangliomas possess the potential for metastasis, actual metastatic occurrences are observed in approximately one third of cases. The metastases primarily affect the lymph nodes, skeletal system, liver, and lungs. Furthermore, patients often experience a reduced overall survival rate attributed to factors such as tumor size, disease advancement, and excessive catecholamine secretion. For several decades, treatment options for patients diagnosed with metastatic pheochromocytomas and paragangliomas have primarily included combination chemotherapy with cyclophosphamide, vincristine, and dacarbazine, along with Iodine-131-metaiodobenzylguanidine. However, significant advancements in scientific research over the past 25 years have enabled a comprehensive characterization of these tumors from biochemical, molecular, and diagnostic standpoints, resulting in the identification of new therapeutic alternatives for affected patients. In the last decade, we have witnessed the introduction of innovative systemic therapies specifically designed for those with metastatic pheochromocytomas and paragangliomas. In this review, we aim to present findings on the efficacy, safety, and overall activity from prospective clinical trials involving radiopharmaceuticals and tyrosine kinase inhibitors, and we will also outline the prospective advantages of additional novel therapies currently under evaluation.

The road ahead: a brief guide to navigating the 2022 WHO classification of endocrine and neuroendocrine tumours

The most recent WHO classification of endocrine and neuroendocrine tumours has brought about significant changes in the diagnosis and grading of these lesions. For instance, pathologists now have the ability to stratify subsets of thyroid and adrenal neoplasms using various histological features and composite risk assessment models. Moreover, novel recommendations on how to approach endocrine neoplasia involve additional immunohistochemical analyses, and the recognition and implementation of these key markers is essential for modernising diagnostic capabilities. Additionally, an improved understanding of tumour origin has led to the renaming of several entities, resulting in the emergence of terminology not yet universally recognised. The adjustments in nomenclature and prognostication may pose a challenge for the clinical team, and care providers might be eager to engage in a dialogue with the diagnosing pathologist, as treatment guidelines have not fully caught up with these recent changes. Therefore, it is crucial for a surgical pathologist to be aware of the knowledge behind the implementation of changes in the WHO classification scheme. This review article will delve into the most significant diagnostic and prognostic changes related to lesions in the parathyroid, thyroid, adrenal glands and the gastroenteropancreatic neuroendocrine system. Additionally, the author will briefly share his personal reflections on the clinical implementation, drawing from a couple of years of experience with these new algorithms.

Durable and deep response to CVD chemotherapy in SDHB-mutated metastatic paraganglioma: case report

INTRODUCTION

Succinate dehydrogenase subunit B (SDHB)-mutated paragangliomas (PGLs) are rare neuroendocrine tumors characterized by increased malignancy, readily metastasizing, and poorer prognosis. Here we report a case of SDHB-mutated metastatic PGL, wherein the patient showed significant tumor shrinkage and complete symptom remission following chemotherapy. We aim to contribute additional evidence to the existing knowledge associated with SDHB-mutated PGLs.

CASE REPORT

A 40-year-old male patient presented with recurrent hypoglycemia and hypertension crisis. Imaging revealed a huge left retroperitoneal tumor and multiple diffuse metastases in lungs. Catecholamine was also elevated, aligning with a diagnosis of metastatic PGL. Pathology also confirmed this diagnosis. Additionally, the immunohistochemistry indicated negative expression of SDHB and gene test showed somatic SDHB mutation. Given the SDHB mutation, cyclophosphamide-vincristine-dacarbazine (CVD) chemotherapy was initiated in critical conditions. Subsequently, a significant tumor shrinkage and complete biochemical response were observed after two treatment cycles. In September 2024, CT scan revealed new pulmonary lesions. The progression-free survival (PFS) with CVD chemotherapy was 24 months.

CONCLUSION

This report reviews the distinct clinical and biochemical characteristics and treatment approaches of SDHB-mutated paragangliomas, emphasizing that the significance of incorporating both genetic testing and immunohistochemical analysis in clinical practice.

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.

A novel strategy for predicting the efficacy of temozolomide treatment for metastatic pheochromocytomas/paragangliomas

BACKGROUND

There are few studies on the efficacy of temozolomide (TMZ) in the treatment of Metastatic pheochromocytoma / paraganglioma (MPP) patients. And it remains unclear which MPP patients may benefit from TMZ treatment.

METHODS

This was a prospective study. MPP patients were enrolled. Patients were treated with TMZ until disease progression or intolerable toxicities. The primary endpoints were disease control rate (DCR) and objective response rate (ORR). Secondary endpoints included biochemical response rate progression-free survival (PFS) and safety. We compared the difference between effective and ineffective groups, to explore which patients are more suitable for TMZ treatment.

RESULTS

62 patients with MPP were enrolled and tumor response were evaluated in 54 patients. The DCR was 83% (35/42), and the ORR was 24% (10/41) among the progressive patients. PFS was 25.2 ± 3.1 months. The most common adverse event was nausea (41/55). We found that 92.9% (13/14) of patients with MGMT methylation greater than 7% respond to treatment. For the patients with MGMT methylation less than 7%, Ki-67 index could be used to guide the use of TMZ in these patients. Among the patients with Ki-67 index less than 5%, 66% (8/12) patients showed respond to treatment, and only 33% (4/12) patients with Ki-67 index more than 5% showed respond to TMZ.

CONCLUSIONS

This study indicated that TMZ is a potential choice for the treatment of MPP with the high ability on disease control and well tolerability. We recommended to MGMT methylation analysis test and Ki-67 index to guide TMZ application.

Rare Findings of Multiple Bone Metastases From Duodenal Gangliocytic Paraganglioma on 68Ga-DOTATATE PET/CT Imaging

ABSTRACT

We present the imaging findings of a 48-year-old woman that metastasized to multiple bones with a history of duodenal gangliocytic paraganglioma. 68Ga-DOTATATE PET/CT showed multiple osteolytic bone destruction with intense uptake. Multiple bone metastases originating from duodenal gangliocytic paraganglioma confirmed histopathological results of a biopsy on the chest-back bone.

The Molecular Classification of Pheochromocytomas and Paragangliomas: Discovering the Genomic and Immune Landscape of Metastatic Disease

Pheochromocytomas (PCCs) and paragangliomas (PGLs, together PPGLs) are the most hereditary tumors known. PPGLs were considered benign, but the fourth edition of the World Health Organisation (WHO) classification redefined all PPGLs as malignant neoplasms with variable metastatic potential. The metastatic rate differs based on histopathology, genetic background, size, and location of the tumor. The challenge in predicting metastatic disease lies in the absence of a clear genotype-phenotype correlation among the more than 20 identified genetic driver variants. Recent advances in molecular clustering based on underlying genetic alterations have paved the way for improved cluster-specific personalized treatments. However, despite some clusters demonstrating a higher propensity for metastatic disease, cluster-specific therapies have not yet been widely adopted in clinical practice. Comprehensive genomic profiling and transcriptomic analyses of large PPGL cohorts have identified potential new biomarkers that may influence metastatic potential. It appears that no single biomarker alone can reliably predict metastatic risk; instead, a combination of these biomarkers may be necessary to develop an effective prediction model for metastatic disease. This review evaluates current guidelines and recent genomic and transcriptomic findings, with the aim of accurately identifying novel biomarkers that could contribute to a predictive model for mPPGLs, thereby enhancing patient care and outcomes.