Imaging of Pheochromocytomas and Paragangliomas

Gastric bronchogenic cyst mimicking adrenal Phaeochromocytoma: a case report

BACKGROUND

Bronchogenic cysts (BCs) are rare foregut-derived cystic malformations that can develop within the respiratory tract. While they are commonly found in the mediastinum or lungs, their occurrence at ectopic sites, such as the stomach, is extremely rare. This case report highlights the challenges in diagnosing a gastric bronchogenic cyst and the potential for misdiagnosis a pheochromocytoma, especially when associated with hypertension.

CASE PRESENTATION

A 47-year-old male presented with a 6-day history of headache and nausea, and was found to have elevated blood pressure. Imaging studies, including computed tomography (CT) scans, suggested the possibility of a pheochromocytoma located near the left adrenal gland. However, subsequent surgical exploration revealed a cystic lesion near the posterior gastric wall, contiguous with the posterior gastric fundus. Pathological examination confirmed the diagnosis of a bronchogenic cyst in the gastric fundus.

DISCUSSION

Bronchogenic cysts are congenital malformations that can present diagnostic challenges, especially when located in atypical sites like the stomach or when associated with hypertension, potentially mimicking pheochromocytoma. Accurate diagnosis relies on imaging, laboratory tests for metanephrines, and careful clinical assessment to differentiate from other tumors.

CONCLUSIONS

Correct differentiation between gastric bronchogenic cysts and pheochromocytoma is crucial, emphasizing the need for thorough diagnostic workup and considerate surgical approach.

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.

Pheochromocytoma and Paragangliomas: Current Management Strategies

Pheochromocytomas and paragangliomas are rare neuroendocrine tumors with complex clinical presentations and potential for malignancy. This review highlights advancements in biochemical testing, imaging, genetic counseling, and surgical management, which have improved diagnostic accuracy and patient outcomes. Minimally invasive surgical approaches are commonly preferred, but open surgery remains necessary for larger or complex tumors. Emerging treatments in the metastatic stage, such as targeted therapies and radioligand therapy, show promise. However, access to advanced imaging and treatment options varies globally, underscoring the need for multidisciplinary care and further research to optimize management strategies.

Bladder paraganglioma in pregnancy with a successful perinatal outcome: a case report

Paragangliomas (PGLs) during pregnancy is an uncommon neuroendocrine tumour that is associated with increased maternal and foetal morbidity and mortality. Furthermore, it is even rarer for these to be located within the urinary bladder, with a prevalence of <0.1% of all bladder tumours. This case report details a 29-year-old female who presented with pre-syncope, headache, and palpitations during voiding. Ultrasound and magnetic resonance imaging of the pelvis revealed a mass in her bladder, and biochemical workup demonstrated elevated plasma normetanephrine levels and a positive clonidine suppression test. Surgical resection and histopathology of the mass were consistent with PGL. Post-operatively, the patient was normotensive, her normetadrenaline levels normalized and she was discharged 3 days after the operation. She progressed through the remaining pregnancy without any significant complications and delivered a healthy baby at full term. This case depicts the rare nature of PGLs in pregnancy and the importance of antenatal imaging combined with a multidisciplinary approach for a successful pregnancy outcome.

Rare tumors II: Adrenocortical tumors, neuroendocrine tumors of the appendix, pheochromocytoma and paraganglioma, pancreatoblastoma and solid pseudopapillary tumors of the pancreas

Very rare tumors are usually divided into two groups: One includes tumors that are rare among both children and adults; the other one encompasses tumors that frequently occur in adults but are rarely observed in children. In this review, we focus on adrenocortical tumors, neuroendocrine tumors of the appendix, pheochromocytoma and paraganglioma, pancreatoblastoma and solid pseudopapillary tumors of the pancreas, with special attention to the role of surgery as main curative intervention or as part of the multimodal treatment.

Genotype-Phenotype Correlations in the Hyperparathyroidism-Jaw Tumor Syndrome

Establishing genotype-phenotype correlations in disorders of hereditary endocrine neoplasia is important for clinical screening, genetic counseling, prognostication, surveillance, and surgical strategy, and may also provide clues about disease pathogenesis. Important genotype-phenotype correlations are recognized, for example, in pheochromocytoma/paraganglioma and multiple endocrine neoplasia type 2A. The presence of such correlations has been less clear in other familial endocrine disorders associated with primary hyperparathyroidism including multiple endocrine neoplasia type 1, and the hyperparathyroidism-jaw tumor syndrome (HPT-JT). Characteristic features of HPT-JT, apart from fibro-osseous jaw tumors and uterine lesions, include renal neoplasms, such as Wilms tumor and mixed epithelial and stromal tumor ("renal hamartomas"), and a high incidence of parathyroid cancer. Emerging evidence suggests two different genotype-phenotype correlations in HPT-JT based on the type of variant in the CDC73 tumor suppressor gene. Although multiple CDC73 genotypes can give rise to the Wilms tumor phenotype in HPT-JT, the development of mixed epithelial and stromal tumor of the kidney specifically correlates with the presence of a start-loss variant affecting the initiator methionine codon of parafibromin, the protein product encoded by CDC73. Furthermore, the risk of parathyroid cancer in HPT-JT also appears to correlate with genotype: CDC73 frameshift indel, splice-site, and stop-gain genotypes are associated with a greatly increased risk of parathyroid carcinoma compared to carriers of CDC73 missense and nonframeshift indel variants. The recognition of such genotype-phenotype correlations in HPT-JT may impact genetic counseling, patient care and disease surveillance.

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.

Von Hippel-Lindau syndrome: clinical features, genetic foundations, and management strategies

Von Hippel-Lindau Syndrome (VHL) is a rare, hereditary disorder characterized by the development of multiple tumors and cysts in various parts of the body due to mutations in the VHL gene on chromosome 3p25-26. Patients with VHL are at increased risk for hemangioblastomas of the brain, spinal cord, and retina, renal cell carcinomas, pheochromocytomas, pancreatic neuroendocrine tumors, and endolymphatic sac tumors. Clinical manifestations vary widely, and early diagnosis through genetic testing and regular surveillance is crucial for effective management. Treatment involves monitoring for tumor development, surgical removal of tumors, and targeted therapies for advanced cases. Recent advances in understanding the VHL pathway have led to new targeted treatments, particularly those involving the hypoxia-inducible factors and vascular endothelial growth factor pathways, which have improved patient outcomes. This article reviews the clinical features, genetic foundations, genotype/phenotype relationship and current management strategies for VHL, emphasizing recent advances that have enhanced prognosis and quality of life for patients.

Adrenal Mass Evaluation: Suspicious Radiological Signs of Malignancy

An adrenal mass discovered incidentally during imaging for unrelated clinical reasons is termed an "adrenal incidentaloma" (AI). AIs can be categorized as primary or metastatic, functioning or non-functioning, and benign or malignant. The primary goal of radiological evaluation is to exclude malignancy by differentiating between benign and malignant lesions. Most AIs are benign, with adenomas and macronodular bilateral adrenal hyperplasia being the most common types. Less common benign lesions include myelolipomas, pheochromocytomas, cysts, and hematomas. Malignant adrenal masses account for less than 10% of cases and often include metastases from other cancers or primary adrenal diseases, such as adrenocortical carcinoma and pheochromocytoma. Computed Tomography (CT) remains the gold standard for diagnosing adrenal incidentalomas, while Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) are utilized for indeterminate cases. Additionally, innovative imaging techniques such as texture analysis are gaining importance, as they can assess quantitative parameters that are not visible to the human eye. This review aims to provide an updated overview of malignant adrenal lesions on CT and MRI, emphasizing key imaging features suspicious for malignancy to aid in distinguishing between benign and malignant lesions. Furthermore, it highlights the growing role of radiomics as a supportive tool for radiologists.

Diagnostic Performance of [18 F] FDOPA PET/CT and Other Tracers in Pheochromocytoma: A Meta-Analysis

RATIONALE AND OBJECTIVES

PET-CT is extensively used in the diagnosis of pheochromocytoma (PHEO). However, various PET-CT tracers are recommended for the diagnosis of PHEO. Therefore, this study evaluated the diagnostic performance of all tracers currently used in the PET-CT detection of PHEO.

METHODS

Studies were retrieved from PubMed, Web of Science, Embase, and Cochrane Library from inception to Feb. 7, 2024. The studies were screened according to the eligibility criteria and the data were extracted. Quality of the included studies was evaluated by the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the summary receiver operating characteristic (sROC) curve (AUC) were pooled in Stata 15, and diagnostic accuracy was pooled in R 4.3.3.

RESULTS

Sixteen studies were included in the meta-analysis. The sensitivity and specificity of [18 F]FDOPA PET/CT for initial PHEO diagnosis were 97% (95% CI: 91%-99%, I2 = 46.14%, p > 0.01) and 94% (95% CI: 86%-98%, I2 = 87.90%, p < 0.01), respectively. The AUC was 0.99 (95% CI: 0.98-1.00). The diagnostic accuracy of [18 F]FDOPA PET/CT was 98.9% (95% CI: 95%-100%) for PHEO patients and 89.7% (95% CI: 85.4%-92.8%) for PHEO lesions. [68Ga]DOTATATE PET/CT had a diagnostic accuracy of 86.9% (95% CI: 78.2%-93.9%) for PHEO and 87.5% (95% CI: 70.3%-95.4%) for PHEO lesions. FDG PET/CT had a diagnostic accuracy of 85.2% (95% CI: 73.6%-94.1%) for PHEO and 86.8% (95% CI: 73%-94.2%) for PHEO lesions. [68Ga]DOTANOC PET/CT had a diagnostic accuracy of 79.3% (95% CI: 49.2%-98.3%) for PHEO.

CONCLUSIONS

In general, PET/CT demonstrates superior performance in the diagnosis of PHEO. In addition, [18 F]FDOPA PET/CT has the best diagnostic performance in PHEO compared with other tracers. Given the limited research on other PET/CT tracers and the potential constraints on their widespread use, additional multicenter and multiregional studies are warranted to further evaluate their diagnostic performance and provide recommendations for clinical use.

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.

A rare case of bladder paraganglioma treated successfully with robotic partial cystectomy

Bladder paragangliomas are rare extra-adrenal urological tumors that account for around 0.05% of bladder cancers. Their diagnosis is often delayed because of the rarity of these tumors. There is a risk of an intraoperative hypertensive crisis if not diagnosed or identified before surgical removal. We describe a case of a 36-year-old lady presented with a 10-year history of post-micturition palpitations and headaches. Her biochemical workup showed raised urinary normetanephrine levels and imaging showed a 123I MIBG-avid bladder mass compatible with bladder paraganglioma, although interestingly almost no tracer was picked up in 68Ga DOTATATE imaging. She was started on phenoxybenzamine to control her blood pressure prior to surgery. She underwent a successful robotic partial cystectomy with no complications. After surgery, she remained symptom-free. Bladder paragangliomas are rare neuroendocrine tumors of the bladder, which need to be diagnosed and managed effectively to avoid intraoperative and long-term complications.

Learning points

It is important for patients with a bladder lesion to have a comprehensive differential assessment and biochemical and radiological investigations including functional imaging.Multiple imaging modalities along with what is available are useful in the assessment of bladder paraganglioma.The key role of the multidisciplinary team is to plan treatment in the perioperative period for minimizing risk, especially in situations where optimal management is actively debated.

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.

SDH-related head and neck paragangliomas: Unraveling PET radiomics beyond 18F-FDG

Radiomics revolutionizes medical imaging by providing quantitative analysis that complements traditional qualitative assessments through advanced computational techniques. In this narrative review we have investigated the impact of succinate dehydrogenase (SDH) pathogenic variants on the radiomic profile of 18F-FDG, 18F-DOPA, and 68Ga-DOTA-peptides PET in paragangliomas, focusing on head and neck localizations (HNPGLs). This influence manifests in uptake intensity and textural heterogeneity, revealing a complex radiomic landscape that may reflect specific tumor behaviors and mutation statuses. By combining radiomic analysis with genetic data, we will gain new insights into the relationship between PET imaging features and underlying molecular changes. In the future, we envision an approach integrating macroscopic indices, such as lesion location, size, and SUV, with advanced computer-based algorithms. This comprehensive analysis could facilitate in vivo predictions of SDH pathogenic variants, thereby encouraging genetic testing, and ultimately improving patient outcomes.

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.

Medullary Thyroid Carcinoma: Imaging

Imaging plays an important role in the early detection and staging of medullary thyroid carcinoma (MTC), as well as in follow-up to locate early recurrence. MTC is a rare, calcitonin-secreting thyroid malignancy that is often diagnosed by ultrasound and calcitonin screening as part of the routine evaluation of any thyroid nodule. If serum calcitonin is elevated, imaging studies are needed for preoperative staging to guide surgical management. This may include ultrasound of the neck and abdomen. CT or MRI studies for more distant disease are performed preoperatively when calcitonin levels are greater than 500 pg/mL. Neither FDG-PET/CT nor F-DOPA-PET/CT is routinely being used for preoperative staging, but may be helpful in individual cases of doubt. Postoperative elevated calcitonin is associated with persistence or recurrence of MTC. Imaging studies to localize tumor tissue in postoperative follow-up include ultrasound, CT, MRI, and PET scans. However, they should be used judiciously, as the impact of treatment is often limited. In addition, even patients with persistent disease may survive long enough to accumulate significant radiation doses from CT or PET scans. Imaging studies are also useful in diagnosing associated components of hereditary MTC, such as pheochromocytoma and primary hyperparathyroidism.

Current views on the role of HIF-2α in the pathogenesis and syndromic presentation of pheochromocytoma and paraganglioma

Pathogenic variants (PVs) in EPAS1, which encodes hypoxia-inducible factor-2α (HIF-2α), could be the underlying genetic cause of about 3%-6% of pheochromocytoma and paragangliomas (PPGLs). EPAS1-related PPGLs may occur as isolated tumors or as part of Pacak-Zhuang Syndrome (PZS) with two or more of a triad of PPGL, polycythemia, and somatostatinoma. HIF-2α plays a critical role in the regulation of the cellular hypoxia pathway. When a gain-of-function PV is acquired, HIF-2α evades steady-state hydroxylation by the prolyl hydroxylase type 2 (PHD2), which accelerates von Hippel-Lindau (VHL)-mediated proteasomal degradation. In this situation, HIF-2α is stabilized and can translocate to the nucleus, inducing the expression of several genes involved in tumorigenesis. This leads to the development of PPGL and other manifestations of PZS. EPAS1-related PPGLs usually occur in the second or third decade of life, more frequently in females, and are usually multiple, adrenal and extra-adrenal, and norepinephrine-secreting. In addition, these tumors carry an increased metastatic potential and have been reported with metastatic disease in up to 30% of cases. While polycythemia is fairly common in PZS, somatostatinomas are rare. It has been suggested that the character of the acquired PV in EPAS1, which affects its binding to PHD2, correlates with certain phenotypes in PZS. PVs in EPAS1 that have been found in related sporadic PPGLs have also been associated with hypoxic conditions including cyanotic congenital heart disease, hemoglobinopathies and high altitude. Understanding the hypoxia pathway and its role in the pathogenesis of PPGL may open a new avenue for developing effective therapies for these tumors. Indeed, one of these therapies is Belzutifan, a HIF-2α inhibitor that is being tested in the treatment of metastatic PPGLs.

[Endocrinology, diabetology and metabolism in the 150 years of the DMW - A long and sustainable relationship]

The DMW is celebrating its 150th anniversary - and this period is precisely when endocrinology and diabetology evolved from the first experiments to molecular biology, genetic, and bioinformatics research. The DMW has always accompanied this process with numerous important publications, some of which are highlighted in this article.

Update on clinical characteristics in the evaluation of phaeochromocytoma and paraganglioma

Pheochromocytomas and sympathetic paragangliomas (PPGL) are rare neuroendocrine tumors originating from chromaffin tissue of the adrenal medulla and extra-adrenal sympathetic paraganglia. Historically, many of these tumors were diagnosed postmortem, earning pheochromocytomas the moniker "great mimic" due to their diverse clinical manifestations that can resemble various other conditions. Over time, the clinical presentation of PPGL has evolved, with a shift from symptomatic or postmortem diagnoses to more frequent incidental discoveries or diagnoses through screening, with postmortem identification now being rare. The development of a clinical scoring system has improved the identification of patients at increased risk for PPGL. Notably, the proportion of PPGL patients with normal blood pressure ranges from 15 % to 40 %, varying based on the clinical context. Despite the tumor's reputation, PPGL is an exceedingly rare cause of resistant hypertension. Management of a pheochromocytoma crisis has advanced, with several classes of drugs available for treatment. However, PPGL during pregnancy remains a significant concern, associated with substantial maternal and fetal mortality rates. Additionally, PPGL can present as rare disorders, including catecholamine-induced cardiomyopathy, Cushing syndrome, and urinary bladder PGL. Given these varied presentations, heightened awareness and prompt recognition of PPGL are crucial for timely diagnosis and treatment, ultimately improving patient outcomes. In this article, we offer an in-depth analysis of the diverse clinical presentations of PPGL, highlighting their complexity and the associated diagnostic and treatment strategies.

SDHA-related phaeochromocytoma and paraganglioma: review and clinical management

Phaeochromocytomas and paragangliomas (collectively termed PPGL) are rare yet highly heritable neuroendocrine tumours, with over one-third of cases associated with germline pathogenic variants (PVs) in numerous genes. PVs in the succinate dehydrogenase subunit-A gene (SDHA) were initially implicated in hereditary PPGL in 2010, and SDHA has since become an important susceptibility gene accounting for up to 2.8% of cases. However, it remains poorly understood, particularly regarding the clinical nature of SDHA PPGL, rates of recurrence and metastasis, and the nature of metastatic disease. We present a narrative review of SDHA-related PPGL, covering pathophysiology, relevance to current clinical practice, and considerations for clinical genetics. We analyse a pool of 107 previously reported cases of SDHA-associated PPGL to highlight the spectrum of SDHA-related PPGL. Our analysis demonstrates that SDHA PPGL occurs across a wide age range (11-81 years) and affects men and women equally. SDHA PPGL typically presents as single tumours (91%), usually occurring in the head and neck (46%) or abdomen (43%, including 15% with phaeochromocytomas). Metastatic disease was reported in 25.5% of cases, with bone (82%) and lymph nodes (71%) being the most common sites of metastasis, often identified many years after the initial diagnosis. A family history of SDHA-related neoplasia was rare, reported in only 4% of cases. Understanding the clinical nature and risks associated with SDHA PVs is essential for facilitating the optimal management of patients and their families.