Malignant Pheochromocytoma and Paraganglioma: 272 Patients Over 55 Years

Diagnostic performance of [68Ga]DOTATATE PET/CT, [18F]FDG PET/CT, MRI of the spine, and whole-body diagnostic CT and MRI in the detection of spinal bone metastases associated with pheochromocytoma and paraganglioma

OBJECTIVE

To compare the diagnostic performance of [68Ga]DOTATATE PET/CT, [18F]FDG PET/CT, MRI of the spine, and whole-body CT and MRI for the detection of pheochromocytoma/paraganglioma (PPGL)-related spinal bone metastases.

MATERIALS AND METHODS

Between 2014 and 2020, PPGL participants with spinal bone metastases prospectively underwent [68Ga]DOTATATE PET/CT, [18F]FDG PET/CT, MRI of the cervical-thoracolumbar spine (MRIspine), contrast-enhanced MRI of the neck and thoraco-abdominopelvic regions (MRIWB), and contrast-enhanced CT of the neck and thoraco-abdominopelvic regions (CTWB). Per-patient and per-lesion detection rates were calculated. Counting of spinal bone metastases was limited to a maximum of one lesion per vertebrae. A composite of all functional and anatomic imaging served as an imaging comparator. The McNemar test compared detection rates between the scans. Two-sided p values were reported.

RESULTS

Forty-three consecutive participants (mean age, 41.7 ± 15.7 years; females, 22) with MRIspine were included who also underwent [68Ga]DOTATATE PET/CT (n = 43), [18F]FDG PET/CT (n = 43), MRIWB (n = 24), and CTWB (n = 33). Forty-one of 43 participants were positive for spinal bone metastases, with 382 lesions on the imaging comparator. [68Ga]DOTATATE PET/CT demonstrated a per-lesion detection rate of 377/382 (98.7%) which was superior compared to [18F]FDG (72.0%, 275/382, p < 0.001), MRIspine (80.6%, 308/382, p < 0.001), MRIWB (55.3%, 136/246, p < 0.001), and CTWB (44.8%, 132/295, p < 0.001). The per-patient detection rate of [68Ga]DOTATATE PET/CT was 41/41 (100%) which was higher compared to [18F]FDG PET/CT (90.2%, 37/41, p = 0.13), MRIspine (97.6%, 40/41, p = 1.00), MRIWB (95.7%, 22/23, p = 1.00), and CTWB (81.8%, 27/33, p = 0.03).

CONCLUSIONS

[68Ga]DOTATATE PET/CT should be the modality of choice in PPGL-related spinal bone metastases due to its superior detection rate.

CLINICAL RELEVANCE STATEMENT

In a prospective study of 43 pheochromocytoma/paraganglioma participants with spinal bone metastases, [68Ga]DOTATATE PET/CT had a superior per-lesion detection rate of 98.7% (377/382), compared to [18F]FDG PET/CT (p < 0.001), MRI of the spine (p < 0.001), whole-body CT (p < 0.001), and whole-body MRI (p < 0.001).

KEY POINTS

• Data regarding head-to-head comparison between functional and anatomic imaging modalities to detect spinal bone metastases in pheochromocytoma/paraganglioma are limited. • [68Ga]DOTATATE PET/CT had a superior per-lesion detection rate of 98.7% in the detection of spinal bone metastases associated with pheochromocytoma/paraganglioma compared to other imaging modalities: [18]F-FDG PET/CT, MRI of the spine, whole-body CT, and whole-body MRI. • [68Ga]DOTATATE PET/CT should be the modality of choice in the evaluation of spinal bone metastases associated with pheochromocytoma/paraganglioma.

Metastatic pheochromocytoma and paraganglioma: Integrating tumor biology in clinical practice

Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors derived from chromaffin cells in the autonomic nervous system. Depending on their location, these tumors are capable of excessive catecholamine production, which may lead to uncontrolled hypertension and other life-threatening complications. They are associated with a significant risk of metastatic disease and are often caused by an inherited germline mutation. Although surgery can cure localized disease and lead to remission, treatments for metastatic PPGL (mPPGL)-including chemotherapy, radiopharmaceutical agents, multikinase inhibitors, and immunotherapy used alone or in combination- aim to control tumor growth and limit organ damage. Substantial advances have been made in understanding hereditary and somatic molecular signaling pathways that play a role in tumor growth and metastasis. Treatment options for metastatic disease are rapidly evolving, and this paper aims to provide a brief overview of the management of mPPGL with a focus on therapy options.

Recent progress in molecular classification of phaeochromocytoma and paraganglioma

Phaeochromocytomas (PC) and paragangliomas (PG) are neural crest cancers with high heritability. Recent advances in molecular profiling, including multi-omics and single cell genomics has identified up to seven distinct molecular subtypes. These subtypes are defined by mutations involving hypoxia-inducible factors (HIFs), Krebs cycle, kinase and WNT signalling, but are also defined by chromaffin differentiation states. PCPG have a dominant proangiogenic microenvironment linked to HIF pathway activity and are generally considered "immune cold" tumours with a high number of macrophages. PCPG subtypes can indicate increased metastatic risk but secondary mutations in telomere maintenance genes TERT or ATRX are required to drive the metastatic phenotype. Molecular profiling can identify molecular therapeutic (e.g. RET and EPAS1) and radiopharmaceutical targets while also helping to support variant pathogenicity and familial risk. Molecular profiling and subtyping of PCPG therefore confers the possibility of nuanced prognostication and individual treatment stratification but this still requires large-scale prospective validation.

Metastatic disease and major adverse cardiovascular events preceding diagnosis are the main determinants of disease-specific survival of pheochromocytoma/paraganglioma: long-term follow-up of 303 patients

Purpose

The natural history in unselected cohorts of patients with pheochromocytoma/ paraganglioma (PPGL) followed for a period >10 years remains limited. We aimed to describe baseline characteristics and outcome of a large cohort and to identify predictors of shorter survival.

Methods

This retrospective single-center study included 303 patients with newly diagnosed PPGL from 1968 to December 31, 2023, in 199 prospectively supplemented since July 2020. Mean follow-up was 11.4 (range 0.3-50) years, germline genetic analyses were available in 92.1%. The main outcome measures were overall (OAS), disease-specific (DSS), recurrence-free (RFS) survival and predictors of shorter survival evaluated in patients with metastases at first diagnosis (n=12), metastatic (n=24) and nonmetastatic (n=33) recurrences and without evidence of PPGL after first surgery (n=234).

Results

Age at study begin was 49.4 ± 16.3 years. There were 72 (23.8%) deaths, 15 (5.0%), 29 (9.6%) and 28 (9.2%) due to PPGL, cardiovascular disease (CVD) and malignant or other diseases, respectively. Median OAS, DSS1 (tumor-related) and DSS2 (DSS1 and death caused by CVD) were 4.8, 5.9 and 5.2 years (patients with metastases at first diagnosis), 21.2, 21.2 and 19.9 years, and 38.0, undefined and 38.0 years (patients with metastatic and with nonmetastatic recurrences, respectively). Major adverse cardiovascular events (MACE) preceded the first diagnosis in 15% (n=44). Shorter DSS2 correlated with older age (P ≤ 0.001), male sex (P ≤ 0.02), MACE (P ≤ 0.01) and primary metastases (P<0.0001, also for DSS1).

Conclusion

The clinical course of unselected patients with PPGL is rather benign. Survival rates remain high for decades, unless there are MACE before diagnosis or metastatic disease.

Approach to the Patient: Concept and Application of Targeted Radiotherapy in the Paraganglioma Patient

Paragangliomas can metastasize, posing potential challenges both in symptomatic management and disease control. Systemic targeted radiotherapies using 131I-MIBG and 177Lu-DOTATATE are a mainstay in the treatment of metastatic paragangliomas. This clinical scenario and discussion aim to enhance physicians' knowledge of the stepwise approach to treat these patients with paraganglioma-targeted radiotherapies. It comprehensively discusses current approaches to selecting paraganglioma patients for targeted radiotherapies and how to choose between the two radiotherapies based on specific patient and tumor characteristics, when either therapy is feasible, or one is superior to another. The safety, efficacy, toxicity profiles, and optimization of these radiotherapies are also discussed, along with other therapeutic options including radiotherapies, available for patients besides these two therapies. Perspectives in radiotherapies of paraganglioma patients are outlined since they hold promising approaches in the near future that can improve patient outcomes.

Management of metastatic pheochromocytomas and paragangliomas: when and what

Recently, the treatment landscape for metastatic pheochromocytomas and paragangliomas (MPPGL) has seen both progress and setbacks. We provide an up-to-date review of the multimodality management of MPPGL and discuss novel opportunities and current challenges in the treatment landscape. Given the unique clinical presentation of MPPGL, we discuss the management of hormone-related clinical sequelae and traditional modalities of therapy. Advances in the understanding of the molecular biology of these diverse tumors have enabled novel strategies such as augmenting DNA damage by targeted delivery of radionuclides such as 131I and 177Lu, abrogating tumor angiogenesis, hypoxia resistance, and DNA damage repair. Despite progress, we address the significant challenges still faced by patients and researchers engaged in efforts to improve outcomes in these rare cancers.

[Diagnosis and management of patients with pheochromocytoma/paraganglioma: Consensus of experts of the Russian Medical Society for Arterial Hypertension and the Multidisciplinary Group for the Diagnosis and Treatment of Neuroendocrine Tumors]

The understanding of the nature of catecholamine-secreting tumors has changed significantly in recent years, affecting terminology and classification. Phaeochromocytoma/paraganglioma (PCC/PG) is a rare neuroendocrine tumor from chromaffin tissue that produces and secretes catecholamines. The incidence of PCC/PG is relatively low, with 2-8 cases per 1 million population per year; among patients with arterial hypertension, their prevalence is 0.2-0.6%. However, delayed diagnosis of PCC/PG is associated with a high risk of cardiovascular complications and a high mortality rate. The consensus presents the clinical manifestations of the disease with an emphasis on the course of arterial hypertension as the most common symptom in PCC/PG; modern ideas about the features of diagnosis, aspects of preoperative preparation, treatment, and follow-up of patients with PCC/PG are considered.

Phaeochromocytoma and paraganglioma

Phaeochromocytomas and paragangliomas are rare catecholamine-producing neuroendocrine tumours which can potentially cause catastrophic crises with high morbidity and mortality. This best practice article considers the causes and presentation of such tumours, screening and diagnostic tests, management of these patients and consideration of family members at risk.

A case of malignant pheochromocytoma with neurofibromatosis type 1 having difficulty in differentiating spinal tumor

Introduction

Neurofibromatosis type 1 is a hereditary condition often associated with pheochromocytomas but rarely with malignant pheochromocytomas. Neurofibromatosis type 1 is often associated with bone lesions, which complicates the distinction between malignant and benign tumors.

Case presentation

A 46-year-old man with a medical history of neurofibromatosis type 1 presented with right abdominal pain. Computed tomography revealed a right adrenal tumor, and metaiodobenzylguanidine scintigraphy showed accumulation in the right adrenal gland and thoracic vertebrae. He was diagnosed with pheochromocytoma, and a right adrenalectomy was performed. After surgery, a bone biopsy was conducted on the spinal lesion, confirming metastasis of pheochromocytoma, prompting irradiation. After that, lung and liver metastases emerged, and chemotherapy with cyclophosphamide, vincristine, and dacarbazine was initiated; however, the disease progressed, and he died 11 months after surgery.

Conclusion

We report a case of malignant pheochromocytoma associated with neurofibromatosis type 1 in which bone metastasis was difficult to diagnose.

Seventy years of pheochromocytomas and paragangliomas in Argentina. The FRENAR database

Pheochromocytomas and paragangliomas (PPGL) are neuroendocrine tumors characterized by the excessive production of catecholamines. This study aims to describe the clinical characteristics of PPGL cases in Argentina over recent decades. A multicenter retrospective cross-sectional analysis was carried out using a database comprising both pediatric and adult patients with confirmed PPGL diagnoses based on pathological reports. A cohort of 486 patients with PPGL was recruited. Women represent 58.4% of the patients, with a mean age of 38.3 years old at the time of diagnosis and 15.2% of the patients were under the age of 18. Hypertension, as well as classic signs and symptoms, were present in 80.9% of the patients. The adrenal incidentaloma, as a mode of presentation, increased in the last two decades rising from 3.9% (1953-2000) to 21.8% (2001-2022), p<0.001. Most tumors were located within the adrenal glands, accounting 83.0% of the cases, with bilateral occurrences noted in 20.0%. The median tumor size was 4.8cm. Local recurrence and metastases were observed in 10.9% and 12.2%. Out of 412 patients, 87.0% exhibited urinary excretion elevation of catecholamines and/or their metabolites. Furthermore, 148 patients, representing 30.4% of the study population, displayed a distinct genetic profile indicative of hereditary syndromes. The distribution of hereditary syndromes revealed that MEN2, VHL, and PGL4 constituted the most prevalent syndromes. This population-based study, spanning seven decades, offers valuable insights into the demographic and clinical characteristics of PPGL patients in Argentina.

High-Specific-Activity 131 I-MIBG for the Treatment of Advanced Pheochromocytoma and Paraganglioma

PATIENTS AND METHODS

The primary endpoints were objective response rate (ORR) and disease control rate (DCR). Secondary endpoints were duration of response, blood pressure control, safety, overall and progression-free survival rates, MIBG uptake, and correlations with genetic background.

RESULTS

The study included 25 patients. Twenty-four patients had distant metastases, 17 (68%) had hormonally active tumors, and 13 (52%) had previously received antineoplastic treatment. In 24 evaluable patients, the ORR was 38%, including 2 patients with complete response, and the DCR was 83%; median time to response was 12.5 months (95% confidence interval, 4.6-25.1). Twelve patients had sporadic disease, among whom the ORR was 25% and DCR was 83%. Twelve patients had hereditary disease ( SDHB , VHL , RET ); among these, the ORR was 50%, and DCR was 83%. Plasma metanephrines normalized in 30% of patients and improved by greater than 50% in 46%. Sixteen patients had hormonally active tumors and hypertension; in 9 (56%) of these, blood pressure normalized, leading to discontinuation of antihypertensive therapy.The most common adverse events were grades 1-2 nausea/vomiting and transient bone marrow suppression. One patient developed premature ovarian failure. Reversible grades 3-4 myelosuppression were seen in 7 patients (28%). One patient had fatal pneumonitis.

CONCLUSIONS

HSA- 131 I-MIBG is associated with a high DCR in patients with MPPGL, regardless of underlying genetic mutation.

Genetic and Molecular Biomarkers in Aggressive Pheochromocytomas and Paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) are rare neoplasms producing catecholamines that occur as hereditary syndromes in 25-40% of cases. To date, PPGLs are no longer classified as benign and malignant tumors since any lesion could theoretically metastasize, even if it occurs only in a minority of cases (approximately 10-30%). Over the last decades, several attempts were made to develop a scoring system able to predict the risk of aggressive behavior at diagnosis, including the risk of metastases and disease recurrence; unfortunately, none of the available scores is able to accurately predict the risk of aggressive behavior, even including clinical, biochemical, and histopathological features. Thus, life-long follow-up is required in PPGL patients. Some recent studies focusing on genetic and molecular markers (involved in hypoxia regulation, gene transcription, cellular growth, differentiation, signaling pathways, and apoptosis) seem to indicate they are promising prognostic factors, even though their clinical significance needs to be further evaluated. The most involved pathways in PPGLs with aggressive behavior are represented by Krebs cycle alterations caused by succinate dehydrogenase subunits (SDHx), especially when caused by SDHB mutations, and by fumarate hydratase mutations that lead to the activation of hypoxia pathways and DNA hypermethylation, suggesting a common pathway in tumorigenesis. Conversely, PPGLs showing mutations in the kinase cascade (cluster 2) tend to display less aggressive behavior. Finally, establishing pathways of tumorigenesis is also fundamental to developing new drugs targeted to specific pathways and improving the survival of patients with metastatic disease. Unfortunately, the rarity of these tumors and the scarce number of cases enrolled in the available studies represents an obstacle to validating the role of molecular markers as reliable predictors of aggressiveness.

Effectiveness of cardiopulmonary bypass for radical resection of giant middle mediastinal paraganglioma

A non-functional middle mediastinal paraganglioma is a rare entity. We describe a case of a 67-year-old woman with a diagnosis of a big mediastinal paraganglioma by endobronchial ultrasound transbronchial needle aspiration after chest CT and 18F-fluorodeoxyglucose positron-emission tomography. The nine centimeter in length tumor was located between the superior vena cava and the posterior portion of the ascending aorta, compressing the left atrium and the trachea and main left bronchus, posteriorly, surrounding the right pulmonary artery. Uniportal right video-thoracoscopic biopsy was unconclusive and complicated by severe hemorrhage, however controlled. Surgical resection was performed via a trans-sternal trans-pericardial approach followed by cardiopulmonary bypass and ascending aorta resection which allows an excellent exposure and greater control of great vessels and heart. Complete resection of the tumor was achieved without perioperative complication except for the left vocal cord palsy. Twelve months late the patient is disease free and in good general conditions.

Functional vagal paraganglioma developing 15 years after resection of a retroperitoneal paraganglioma

The patient, a 40-year-old woman, was diagnosed as having a functional right vagal paraganglioma (PGL) 15 years after undergoing resection for a retroperitoneal PGL. 123I-MIBG scintigraphy showed no accumulation, but as the blood noradrenaline and urinary normetanephrine concentrations were elevated, the tumor was judged as being functional, and surgery was scheduled. The patient was started on doxazosin infusion and embolization of the tumor feeding vessel was performed before the surgery. Intraoperative examination showed that the tumor was contiguous with the vagal nerve, necessitating combined resection of the vagal nerve with the tumor. Postoperatively, the catecholamine levels returned to normal range. Histopathologically, the tumor was diagnosed as a moderately differentiated, intermediate-malignant-grade PGL, with a GAPP score of 4 to 6. No non-chromaffin tissue was observed in the tumor background, so that the functional vagal PGL was considered as a sporadic metachronous tumor rather than as a metastasis from the retroperitoneal PGL. More than half of head and neck paragangliomas (HNPGLs) are reported to arise in the carotid body, and about 5% from the vagal nerve. In addition, HNPGLs rarely produce catecholamines. Herein, we consider the relationship with the previously resected retroperitoneal PGL based on a review of the literature.

Prevalence and prognosis of hypoxia-inducible factor-2α (HIF-2α) pathway gene mutations across advanced solid tumors

INTRODUCTION

Hypoxia-inducible factor-2α (HIF-2α) modulates the hypoxic response pathway in tumors; however, mutations in pathways (including SDHA, SDHB, SDHC, SDHD, FH, and VHL genes) that are suspected to activate HIF-2α are poorly understood, with limited understanding of the prevalence and clinical prognosis.

METHODS

This retrospective observational study used a de-identified nationwide (US-based) clinico-genomic database (CGDB) across 15 available tumor types.

RESULTS

Among the 9467 adult patients with advanced/metastatic solid tumors included in the analysis, any mutation at the above-mentioned six genes was observed in 1.8% (95% CI: 1.5-2.1) of patients. The mutation prevalence ranged from 0.05% of SDHD to 0.93% of VHL. When further stratified by tumor type, the prevalence of gene mutation in each tumor type was well below 1%, except for VHL with 44% in renal cell carcinomas (RCC). Excluding RCC, the prevalence of any HIF-2α gene mutations in the study population was 0.9% (95% CI: 0.8-1.2). The median overall survival (OS) from 1 and 2 L therapy among patients with any HIF-2α gene mutation was 14.5 (95% CI: 11.5-24.2) and 9.3 (95% CI: 6.0-18.1) months, respectively, compared with 13.4 (95% CI: 12.9-13.9) and 9.8 (95% CI: 9.3-10.4) months among patients without HIF-2α gene mutations.

DISCUSSION AND CONCLUSIONS

The prevalence of HIF-2α related gene mutations was generally low (<1%) across the 15 solid tumor types, except for VHL in RCC. No significant association between HIF-2α gene mutation status and OS was identified among patients evaluated in this study.

Current management of carotid body tumors

Carotid body tumors (CBTs) are neoplasms that occur at the bifurcation of the carotid artery and are pathologically classified as paragangliomas. In the 4th edition of the WHO classification, paragangliomas are categorized as neoplasms with malignant potential. Clinically, about 5% of CBTs present with malignant features such as metastasis. Currently, it is challenging to distinguish between tumors with benign courses and those that present malignantly. Recent advances in genetic testing have elucidated the genetic characteristics of paragangliomas, including carotid body tumors. Over 20 genes have been identified as being involved in tumor development. Particularly in head and neck paragangliomas, abnormalities in genes related to succinate dehydrogenase are frequently observed. Research is ongoing to understand the mechanisms by which these genes contribute to tumor development. The definitive treatment for CBTs is surgical resection. These tumors are prone to bleeding and often adhere firmly to the carotid artery, making intraoperative bleeding control challenging. The risk of lower cranial nerve paralysis is relatively high, and there is a risk of stroke because of manipulation of the carotid artery. Preoperative evaluation with angiography is essential, and a multi-disciplinary surgical team approach is necessary. In cases where the tumor is difficult to resect or has metastasized, radiation therapy or chemotherapy are employed. Clinical trials involving targeted molecular therapies and radiopharmaceuticals have recently been conducted, with some applied clinically. The development of various new treatments is anticipated, providing hope for therapeutic options in refractory cases.

Paragangliomas of the Head and Neck: A Review of the Latest Diagnostic and Treatment Methods

Background and objectives: Paragangliomas of the head and neck are rare, slow-growing neuroendocrine tumors, benign in their vast majority, but with a possibility of developing distant metastases. They show great inheritable character, and their behavior has proven to be unpredictable; therefore, they are considered malignant. Material and methods: This article aims to offer a more comprehensive presentation of the pathogenesis, epidemiology, diagnostic methods, imaging development, and treatment guidelines. We tried to bring together all the necessary data that, in our opinion, a head and neck practitioner should know when managing this type of tumor. Our main focus is on the most recent studies, with the purpose of a homogenous presentation of all current guidelines and approaches to this pathology. Results: Paragangliomas of the head and neck are still a disputed topic. One of the main reasons for that is their low incidence of 0.3 to 1 per 100,000 every year. The most frequent locations are the carotid body, the temporal bone, the jugular and mastoid foramen, and the vagal nerve. Their clinical presentation usually involves a painless lateral mass associated with symptoms such as hoarseness, hearing loss, tinnitus, and cranial nerve deficits. Up to 40% of them are inherited, mostly linked with mutations of succinate dehydrogenase complex. Imaging evaluation consists of CT and MRI, and new functional explorations such as 18F-FDA and 18F-FDG PET/CT, 18F-DOPA PET, 123I-MIBG, and 68Ga-DOTATE PET/CT. Measuring the catecholamine levels in the plasma and urine is mandatory, even though paragangliomas of the head and neck rarely display secretory behavior. Treatment mainly consists of surgery, with different approaches and techniques, but conservative management methods such as wait and scan, radiotherapy, proton therapy, and chemotherapy have proven their efficiency. The therapeutical decision lacks consensus, and current studies tend to recommend an individualized approach. Guidelines regarding long-term follow-up are still a matter of debate.

Identification of Predictors of Metastatic Potential in Paragangliomas to Develop a Prognostic Score (PSPGL)

Context

Paragangliomas (PGLs) are rare tumors in adrenal and extra-adrenal locations. Metastasis are found in approximately 5% to 35% of PGLs, and there are no reliable predictors of metastatic disease.

Objective

This work aimed to develop a prognostic score of metastatic potential in PGLs.

Methods

A retrospective analysis was conducted of clinical data from a cohort with PGLs and tumor histological assessment. Patients were divided into metastatic PGL (presence of metastasis) and nonmetastatic PGL (absence of metastasis ≥96 months of follow-up) groups. Univariate and multivariable analysis were performed to identify predictors of metastatic potential. A prognostic score was developed based on coefficients of multivariable analysis. Kaplan-Meier curves were generated to estimate disease-specific survival (DSS).

Results

Out of 263 patients, 35 patients had metastatic PGL and 110 patients had nonmetastatic PGL. In multivariable analysis, 4 features were independently related to metastatic disease and composed the Prognostic Score of Paragangliomas (PSPGL): presence of central or confluent necrosis (33 points), more than 3 mitosis/10 high-power field (HPF) (28 points), extension into adipose tissue (20 points), and extra-adrenal location (19 points). A PSPGL of 24 or greater showed similar sensitivity with higher specificity than the Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) and Grading System for Adrenal Pheochromocytoma and Paraganglioma (GAPP). PSPGL less than or equal to 20 was associated with a risk of metastasis of approximately 10%, whereas a PSPGL of 40 or greater was associated with approximately 80%. The presence of metastasis and Ki-67 of 3% or greater were related to lower DSS.

Conclusion

The PSPGL, composed of 4 easy-to-assess parameters, demonstrated good performance in predicting metastatic potential and good ability in estimating metastasis risk.

Novel alternative tools for metastatic pheochromocytomas/paragangliomas prediction

OBJECTIVE

The existing prediction models for metastasis in pheochromocytomas/paragangliomas (PPGLs) showed high heterogeneity in different centers. Therefore, this study aimed to establish new prediction models integrating multiple variables based on different algorithms.

DESIGN AND METHODS

Data of patients with PPGLs undergoing surgical resection at the Peking Union Medical College Hospital from 2007 to 2022 were collected retrospectively. Patients were randomly divided into the training and testing sets in a ratio of 7:3. Subsequently, decision trees, random forest, and logistic models were constructed for metastasis prediction with the training set and Cox models for metastasis-free survival (MFS) prediction with the total population. Additionally, Ki-67 index and tumor size were transformed into categorical variables for adjusting models. The testing set was used to assess the discrimination and calibration of models and the optimal models were visualized as nomograms. Clinical characteristics and MFS were compared between patients with and without risk factors.

RESULTS

A total of 198 patients with 59 cases of metastasis were included and classified into the training set (n = 138) and testing set (n = 60). Among all models, the logistic regression model showed the best discrimination for metastasis prediction with an AUC of 0.891 (95% CI, 0.793-0.990), integrating SDHB germline mutations [OR: 96.72 (95% CI, 16.61-940.79)], S-100 (-) [OR: 11.22 (95% CI, 3.04-58.51)], ATRX (-) [OR: 8.42 (95% CI, 2.73-29.24)] and Ki-67 ≥ 3% [OR: 7.98 (95% CI, 2.27-32.24)] evaluated through immunohistochemistry (IHC), and tumor size ≥ 5 cm [OR: 4.59 (95% CI, 1.34-19.13)]. The multivariate Cox model including the above risk factors also showed a high C-index of 0.860 (95% CI, 0.810-0.911) in predicting MFS after surgery. Furthermore, patients with the above risk factors showed a significantly poorer MFS (P ≤ 0.001).

CONCLUSIONS

Models established in this study provided alternative and reliable tools for clinicians to predict PPGLs patients' metastasis and MFS. More importantly, this study revealed for the first time that IHC of ATRX could act as an independent predictor of metastasis in PPGLs.

Recent advances in the development of 225Ac- and 211At-labeled radioligands for radiotheranostics

Radiotheranostics utilizes a set of radioligands incorporating diagnostic or therapeutic radionuclides to achieve both diagnosis and therapy. Imaging probes using diagnostic radionuclides have been used for systemic cancer imaging. Integration of therapeutic radionuclides into the imaging probes serves as potent agents for radionuclide therapy. Among them, targeted alpha therapy (TAT) is a promising next-generation cancer therapy. The α-particles emitted by the radioligands used in TAT result in a high linear energy transfer over a short range, inducing substantial damage to nearby cells surrounding the binding site. Therefore, the key to successful cancer treatment with minimal side effects by TAT depends on the selective delivery of radioligands to their targets. Recently, TAT agents targeting biomolecules highly expressed in various cancer cells, such as sodium/iodide symporter, norepinephrine transporter, somatostatin receptor, αvβ3 integrin, prostate-specific membrane antigen, fibroblast-activation protein, and human epidermal growth factor receptor 2 have been developed and have made remarkable progress toward clinical application. In this review, we focus on two radionuclides, 225Ac and 211At, which are expected to have a wide range of applications in TAT. We also introduce recent fundamental and clinical studies of radiopharmaceuticals labeled with these radionuclides.

Peptide receptor radionuclide therapy with 177Lu- or 90Y-SSTR peptides in malignant pheochromocytomas (PCCs) and paragangliomas (PGLs): results from a single institutional retrospective analysis

BACKGROUND

Malignant pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare tumors and available systemic therapies are limited.

AIM

To explore the role of peptide receptor radionuclide therapy (PRRT) with Yttrium-90 (90Y) and Lutetium-177 (177Lu) peptides in pheochromocytomas (PCCs) and paragangliomas (PGLs).

METHODS

We retrospectively analyzed more than 1500 patients with histologically proven neuroendocrine tumors treated with 177Lu- or 90Y-DOTA-TATE or -TOC between 1999 to 2017 at our Institute. Overall, 30 patients with confirmed malignant PCCs and PGLs matched inclusion/exclusion criteria and were considered eligible for this analysis.

RESULTS

Thirty (n = 30) patients were treated: 22 with PGLs and 8 with PCCs (12 M and 18 F, median age 47 [IQR: 35-60 years]). Eighteen patients (n = 18) had head and neck PGLs, 3 patients thoracic PGLs and 1 patient abdominal PGL. Sixteen patients (53%) had locally advanced and fourteen (47%) had metastatic disease. Twenty-seven (90%) patients had disease progression at baseline. Four (13%) patients were treated with 90Y, sixteen (53%) with 177Lu and ten (33%) with 90Y + 177Lu respectively. The median total cumulative activity from treatment with 90Y- alone was 9.45 GBq (range 5.11-14.02 GBq), from 177Lu- alone was 21.9 GBq (7.55-32.12 GBq) and from the combination treatment was 4.94 GBq from 90Y- and 6.83 GBq from 177Lu- (ranges 1.04-10.1 and 2.66-20.13 GBq, respectively). Seven out of 30 (23%) patients had partial response and 19 (63%) stable disease. Median follow up was 8.9 years (IQR: 2.9-12). The 5-y and 10-y PFS was 68% (95% CI: 48-82) and 53% (95% CI: 33-69), respectively, whereas 5-y and 10-y OS was 75% (95% CI: 54-87) and 59% (95% CI: 38-75), respectively. Grade 3 or 4 acute hematological toxicity occurred in three patients, two with leucopenia and one with thrombocytopenia, respectively.

CONCLUSION

PRRT with 177Lu- or 90Y-DOTA-TATE or -TOC is feasible and well tolerated in advanced PGLs and PCCs.

Recurrent Pheochromocytoma With Bone Metastasis Eight Years After Bilateral Adrenalectomies in a Patient With Neurofibromatosis Type 1

Background/Objective

Pheochromocytoma can recur years after curative surgical resection. Rarely, it may reoccur as metastasis. Here, we present a case of metastatic pheochromocytoma to the bones in a patient with neurofibromatosis type 1 (NF1), 8 years after initial resection of primary bilateral adrenal pheochromocytomas without metastases.

Case Report

A 44-year-old woman presented with diffuse body pain and palpitations. Her past medical history included NF1 and hypertension. Eight years prior to her current presentation, she had undergone a bilateral adrenalectomy for the management of bilateral adrenal pheochromocytomas. Her plasma metanephrines normalized after surgery and remained normal at her 1-year postoperative visit. She was subsequently lost to follow-up until her current presentation. Our evaluation revealed significantly elevated urine and plasma metanephrines as well as innumerable DOTATATE avid lesions along the axial and perpendicular spine compatible with a metastatic neuroendocrine tumor. She was started on doxazosin and metoprolol and discharged home with a plan to be seen by Oncology to discuss systemic therapy.

Discussion

Predicting malignant disease in patients with primary tumors without metastases is challenging. There is no single factor that can reliably predict tumor behavior. It is unknown if individuals with NF1, who have a genetic predisposition for developing pheochromocytomas, are at an increased risk of malignant disease.

Conclusion

Due to a lack of accurate predictors, annual biochemical testing is recommended after primary tumor resection and in patients with a genetic predisposition. Strict lifelong follow-up should be strongly considered due to a possible higher risk of malignant disease.

Head and Neck Malignant Paragangliomas: Experience from a Single Institution

Objectives: To summarize the clinicopathological and genetic features of malignant paragangliomas in head and neck cancer and to explore the appropriate treatment options for this rare lesion. Methods: Six patients harboring head and neck malignant paraganglioma from Beijing Tongren Hospital were retrospectively reviewed. The clinicopathological characteristics, gene mutations, and prognosis of these patients were analyzed. Results: Of these 6 patients, 3 were male and 3 were female; 4 patients harbored malignant carotid body tumors, and two had malignant vagal paragangliomas. Three patients had cervical lymph node metastasis, two presented with lung and bone metastasis, and 1 had lung and liver metastasis. Of the 6 patients, four underwent surgical resection, and the other two patients denied surgery and instead received chemotherapy with paclitaxel, ifosfamide, and dacarbazine. These 2 patients with vagal paraganglioma received postoperative radiotherapy. All 6 patients are still alive at the present time, with a median follow-up time of 66 months. Positive Ki-67 expression in tumor tissue ranged from 1% to 40%. Genetic mutations in SDHD, SDHB, ATR, and MAP3K13 were identified in 4 patients. Conclusions: After comprehensive treatment, head and neck malignant paraganglioma can attain a favorable prognosis. Genetic mutations are commonly detected in patients with malignant paragangliomas. This study also identified mutations in ATR and MAP3K13 in these patients.

Unrecognised paraganglioma of the urinary bladder precipitating hypertensive crisis

Bladder paragangliomas (bPGLs) account for only 0.06% of all bladder tumours, most commonly presenting with post-micturition syncope and hypertensive crisis. Silent paragangliomas are very rare, and failure to recognise them in the perioperative setting can precipitate a hypertensive crisis in the absence of sufficient alpha-blockade. Here, we describe a case of unrecognised bPGL in a woman with pre-existing hypertension and a single prior episode of haematuria thought to be related to urothelial carcinoma. She was found to have a low-grade non-invasive papillary urothelial carcinoma (potentially the cause of her haematuria) and an unrelated vascular-appearing tumour causing hypertensive crisis and broad complex tachycardia on resection. This was confirmed to be a bPGL on histology for which she underwent definitive management with a partial cystectomy following blood pressure management.

Tumor metabolism in pheochromocytomas: clinical and therapeutic implications

Pheochromocytomas and paragangliomas (PPGLs) have emerged as one of the most common endocrine tumors. It epitomizes fascinating crossroads of genetic, metabolic, and endocrine oncology, providing a canvas to explore the molecular intricacies of tumor biology. Predominantly rooted in the aberration of metabolic pathways, particularly the Krebs cycle and related enzymatic functionalities, PPGLs manifest an intriguing metabolic profile, highlighting elevated levels of oncometabolites like succinate and fumarate, and furthering cellular malignancy and genomic instability. This comprehensive review aims to delineate the multifaceted aspects of tumor metabolism in PPGLs, encapsulating genetic factors, oncometabolites, and potential therapeutic avenues, thereby providing a cohesive understanding of metabolic disturbances and their ramifications in tumorigenesis and disease progression. Initial investigations into PPGLs metabolomics unveiled a stark correlation between specific genetic mutations, notably in the succinate dehydrogenase complex (SDHx) genes, and the accumulation of oncometabolites, establishing a pivotal role in epigenetic alterations and hypoxia-inducible pathways. By scrutinizing voluminous metabolic studies and exploiting technologies, novel insights into the metabolic and genetic aspects of PPGLs are perpetually being gathered elucidating complex interactions and molecular machinations. Additionally, the exploration of therapeutic strategies targeting metabolic abnormalities has burgeoned harboring potential for innovative and efficacious treatment modalities. This review encapsulates the profound metabolic complexities of PPGLs, aiming to foster an enriched understanding and pave the way for future investigations and therapeutic innovations in managing these metabolically unique tumors.

Comprehensive Investigation of Angiogenesis, PASS Score and Immunohistochemical Factors in Risk Assessment of Malignancy for Paraganglioma and Pheochromocytoma

A challenging task in routine practice is finding the distinction between benign and malignant paragangliomas and pheochromocytomas. The aim of this study is to conduct a comparative analysis of angiogenesis by assessing intratumoral microvascular density (MVD) with immunohistochemical (IHC) markers (CD31, CD34, CD105, ERG), and S100 immunoreactivity, Ki67 proliferative index, succinate dehydrogenase B (SDHB) expressiveness, tumor size with one the most utilized score Pheochromocytoma of Adrenal Gland Scales Score (PASS), using tissue microarray (TMA) with 115 tumor samples, 61 benign (PASS < 4) and 54 potentially malignant (PASS ≥ 4). We found no notable difference between intratumoral MVD and potentially malignant behavior. The group of potentially malignant tumors is significantly larger in size, has lower intratumoral MVD, and a decreased number of S100 labeled sustentacular cells. Both groups have low proliferative activity (mean Ki67 is 1.02 and 1.22, respectively). Most tumors maintain SDHB expression, only 6 cases (5.2%) showed a loss of expression (4 of them in PASS < 4 group and 2 in PASS ≥ 4). PASS score is easily available for assessment and complemented with markers of biological behavior to complete the risk stratification algorithm. Size is directly related to PASS score and malignancy. Intratumoral MVD is extensively developed but it is not crucial in evaluating the malignant potential.

Case report: Rare case of a preoperatively diagnosed spermatic cord paraganglioma and literature review

Paraganglioma (PGL) is rare, and PGL that arises from the urogenital system is even rarer. Here we report a case of PGL in spermatic cord and review the relevant literatures. We encountered a 15-year-old boy with a history of hypertension for almost 2 years, accompanied with headache and palpitations. His serum and urine catecholamines were elevated, but no adrenal lesions were detected, suggesting the existence of PGL. Upon physical examination, a painless nodule adherent to the spermatic cord in the right scrotum was found. A systemic Ga68 DOTATATE PET-CT was then performed, and it revealed a mass with high DOTATATE uptake in the right scrotum. The CT, MRI, and ultrasound images showed the abundant blood supply to the tumor. Based on the above-mentioned imaging and biochemical information, a diagnosis of PGL was made prior to surgery. After 2 weeks of preparation with Cardura, an open surgery was performed to remove the tumor together with the right testis and right epididymis. The blood pressure increased to 180/100 mmHg when the tumor was touched intraoperatively and decreased to 90/55 mmHg after the tumor was removed. Post-operative pathology confirmed our diagnosis of PGL originating from the spermatic cord. Immunohistochemical (IHC) staining showed SDHB (+), CgA (+), synaptophysin (+), GATA3 (+), CD56 (+), sertoli cells S-100 (+), and Ki67 (5%). Genetic testing revealed a missense mutation in the SDHA gene. Only 16 cases of spermatic cord PGL have been reported to date. Although it is easy to diagnose by histology and IHC examinations, preoperative diagnosis is quite important as it can actually reduce intraoperative complications.

Anlotinib for Metastatic Progressed Pheochromocytoma and Paraganglioma: A Retrospective Study of Real-World Data

Introduction

Pheochromocytomas (PCC) and paragangliomas (PGL) (collectively PPGL) are a type of rare hypervascular neuroendocrine tumors that are very challenging to treat. This study aimed to determine the efficacy and safety of the multi-tyrosine kinase inhibitor anlotinib for the treatment of locally advanced or metastatic (LA/M) PPGL.

Methods

A total of 37 eligible patients with unresectable or progressive LA/M PPGL were enrolled. Of them, 27 patients received anlotinib alone (n = 19) or in combination (n = 8) with radionuclide therapies, including peptide receptor radionuclide therapy (PRRT) and iodine 131 meta-iodobenzylguanidine (131I-MIBG). The primary endpoints included objective response rate (ORR), defined as partial response (PR) or complete response (CR), and disease-control rate, defined as PR, CR, or stable disease (SD). The secondary endpoints were progression-free survival (PFS), duration of response, and drug safety.

Results

In the efficacy evaluation for all 27 patients, the ORR was 44.44% (95% CI: 24.4%-64.5%) and disease-control rate was 96.29% (95% CI: 88.7%-100%). Twelve cases (44.44%) achieved PR, 14 (51.85%) SD. The median PFS was 25.2 months (95% CI: 17.2 months to not reached). PFS was shorter in the anlotinib monotherapy group than in the group receiving anlotinib in combination with radionuclide therapy (P = .2). There were no serious treatment-related AEs.

Conclusion

Anlotinib monotherapy or in combination with radionuclide therapies shows promising efficacy and safety for the treatment of LA/M PCC and PGL. Multi-tyrosine kinase inhibitors might represent a novel therapeutic strategy for patients with PPGL; however, large-scale prospective randomized, blinded, controlled clinical research studies are required.

Patient Sex and Origin Influence Distribution of Driver Genes and Clinical Presentation of Paraganglioma

Context

Sexual and ancestral differences in driver gene prevalence have been described in many cancers but have not yet been investigated in pheochromocytoma and paraganglioma (PPGL).

Objective

This study aims to assess whether sex and ancestry influence prevalence of PPGL driver genes and clinical presentation.

Methods

We conducted a retrospective analysis of patients with PPGL considering studies from 2010 onwards that included minimal data of type of disease, sex, mutated gene, and country of origin. Additional features were recorded when available (age, tumor location, bilateral or multifocal, somatic or germline, and metastatic disease).

Results

We included 2162 patients: 877 in Europe and 757 in Asia. Males presented more often with germline pathogenic variants (PVs) in genes activating hypoxia pathways (P = .0006) and had more often sympathetic paragangliomas (P = .0005) and metastasis (P = .0039). On the other hand, females with PPGLs due to MAX PVs were diagnosed later than males (P = .0378) and more often developed metastasis (P = .0497). European but not Asian females presented more often with PPGLs due to PVs in genes related to kinase signaling (P = .0052), particularly RET and TMEM127. Contrary to experiences from Europe, Asian patients with PPGL due to PVs in kinase signaling genes NF1, HRAS, and FGFR1 showed a high proportion of sympathetic tumors, while European patients almost exclusively had adrenal tumors (P < .005).

Conclusion

Personalized management of patients with PPGL might benefit from considering sexual and ancestral differences. Further studies with better clinically aligned cohorts from various origins are required to better dissect ancestral influences on PPGL development.

Pediatric malignant pheochromocytoma with atypical presentation as vision changes, lung metastasis, and recurrence: a case report

BACKGROUND

This case report documents a case of malignant pheochromocytoma manifested as vision changes with lung metastasis and recurrence.

CASE PRESENTATION

A 10-year-old Han Chinese girl presented with vision changes and was eventually diagnosed with pheochromocytoma by contrast-enhanced computed tomography, urine vanillylmandelic acid. After medication for hypertension and surgery, clinical symptoms disappeared. Malignant pheochromocytoma with lung metastasis was confirmed histologically using the Pheochromocytoma of the Adrenal Gland Scaled Score scoring system and genetically with succinate dehydrogenase complex iron sulfur subunit B mutation, and 3 months later, unplanned surgery was performed because of the high risks and signs of recurrence. She is asymptomatic as of the writing of this case report. Our patient's case highlights the importance of considering a diagnosis of malignant pheochromocytoma, and long-term follow-up for possible recurrence.

CONCLUSION

Although there are well-recognized classic clinical manifestations associated with pheochromocytoma, atypical presentation, such as vision changes in children, should be considered. In addition, malignant pheochromocytoma children with a high Pheochromocytoma of the Adrenal Gland Scaled Score and succinate dehydrogenase complex iron sulfur subunit B mutation require a long-term follow-up or even unplanned surgery because of the higher risk of recurrence.

Management of phaeochromocytoma and paraganglioma in patients with germline SDHB pathogenic variants: an international expert Consensus statement

Adult and paediatric patients with pathogenic variants in the gene encoding succinate dehydrogenase (SDH) subunit B (SDHB) often have locally aggressive, recurrent or metastatic phaeochromocytomas and paragangliomas (PPGLs). Furthermore, SDHB PPGLs have the highest rates of disease-specific morbidity and mortality compared with other hereditary PPGLs. PPGLs with SDHB pathogenic variants are often less differentiated and do not produce substantial amounts of catecholamines (in some patients, they produce only dopamine) compared with other hereditary subtypes, which enables these tumours to grow subclinically for a long time. In addition, SDHB pathogenic variants support tumour growth through high levels of the oncometabolite succinate and other mechanisms related to cancer initiation and progression. As a result, pseudohypoxia and upregulation of genes related to the hypoxia signalling pathway occur, promoting the growth, migration, invasiveness and metastasis of cancer cells. These factors, along with a high rate of metastasis, support early surgical intervention and total resection of PPGLs, regardless of the tumour size. The treatment of metastases is challenging and relies on either local or systemic therapies, or sometimes both. This Consensus statement should help guide clinicians in the diagnosis and management of patients with SDHB PPGLs.

Bone metastasis manifested 52 years after resection of an apparently benign paraganglioma: A case report

Paraganglioma is derived from the paraganglia tissue in the neck, along the sympathetic trunk, and in the pelvis. Paraganglioma has malignant potential and can metastasize to remote organs such as the liver, lungs, and bones. Most metachronous metastases occur within several years after the initial diagnosis of paraganglioma. Here, we report the case of a 71-year-old male patient who developed bony metastasis 52 years after the resection of a large paraganglioma at the aortic bifurcation. The biopsy-proven paraganglioma metastasis to the lesser trochanter of left femur presented as an avulsion fracture. His normetanephrine level was elevated. DOTATATE PET (positron emission tomography) did not find any other metastatic lesions. The bony metastasis was treated with radiation therapy. We believe that the patient had one of the longest gaps ever reported, 52 years, between the initial diagnosis and metastasis of paraganglioma. This case highlights the importance of long-term surveillance of patients with paraganglioma for metastasis.

Diagnosis and Management of Pheochromocytomas and Paragangliomas: A Guide for the Clinician

OBJECTIVE

The aim of this review was to provide a practical approach for clinicians regarding the diagnosis and management of pheochromocytomas and paragangliomas (PPGLs).

METHODS

A literature search of PubMed was carried out using key words, including pheochromocytoma, paraganglioma, treatment, diagnosis, screening, and management. The discussion of diagnosis and management of PPGL is based on the evidence available from prospective studies when available and mostly from cohort studies, cross-sectional studies, and expert consensus.

RESULTS

PPGL are neuroendocrine tumors arising from the chromaffin cells of adrenal medulla and sympathetic and parasympathetic ganglia, respectively. PPGL can be localized or metastatic, and they may secrete catecholamines, causing a variety of symptoms and potentially catastrophic and lethal complications if left untreated. The rarity of these tumors along with heterogeneous clinical presentation often poses challenges for the diagnosis and management. PPGL can be associated with several familial syndromes which are important to recognize.

CONCLUSION

The last few years have witnessed an exponential growth in the knowledge around PPGL. This review aims at providing a comprehensive discussion of current concepts for clinicians regarding clinical presentation, diagnostic tools, and management strategies for PPGL.

Paragangliomas and Anemia: Literature Review and Case Report

Paragangliomas are rare neuroendocrine tumors that arise from the extra-adrenal autonomic paraganglia, i.e., small organs consisting mainly of neuroendocrine cells that are derived from the embryonic neural crest and have the ability to secrete catecholamines. Paragangliomas can derive from either parasympathetic or sympathetic paraganglia. Most of the parasympathetic ganglia-derived paragangliomas are nonfunctional, and symptoms result from mass effect. Conversely, the sympathetic paragangliomas are functional and produce catecholamine. Although such patients could have symptoms similar to pheochromocytoma, mass effect symptoms, or non-specific symptoms, being benign tumors, they can also present with anemia, specifically iron-deficiency anemia. Considering that neoplastic pathology is chronically accompanied by moderate, normochromic, normocytic anemia, association between paragangliomas that are mostly benign but with a potential degree of malignancy and anemia is not as frequent as expected, with only 12 cases reported in the literature. We report a case of a 54-year-old female patient diagnosed with a paraganglioma of the carotid glomus accompanied by severe normochromic, normocytic anemia, which reached normal limits after excision of the paraganglioma.

Pheochromocytoma: a changing perspective and current concepts

This article aims to review current concepts in diagnosing and managing pheochromocytoma and paraganglioma (PPGL). Personalized genetic testing is vital, as 40-60% of tumors are linked to a known mutation. Tumor DNA should be sampled first. Next-generation sequencing is the best and most cost-effective choice and also helps with the expansion of current knowledge. Recent advancements have also led to the increased incorporation of regulatory RNA, metabolome markers, and the NETest in PPGL workup. PPGL presentation is highly volatile and nonspecific due to its multifactorial etiology. Symptoms mainly derive from catecholamine (CMN) excess or mass effect, primarily affecting the cardiovascular system. However, paroxysmal nature, hypertension, and the classic triad are no longer perceived as telltale signs. Identifying high-risk subjects and diagnosing patients at the correct time by using appropriate personalized methods are essential. Free plasma/urine catecholamine metabolites must be first-line examinations using liquid chromatography with tandem mass spectrometry as the gold standard analytical method. Reference intervals should be personalized according to demographics and comorbidity. The same applies to result interpretation. Threefold increase from the upper limit is highly suggestive of PPGL. Computed tomography (CT) is preferred for pheochromocytoma due to better cost-effectiveness and spatial resolution. Unenhanced attenuation of >10HU in non-contrast CT is indicative. The choice of extra-adrenal tumor imaging is based on location. Functional imaging with positron emission tomography/computed tomography and radionuclide administration improves diagnostic accuracy, especially in extra-adrenal/malignant or familial cases. Surgery is the mainstay treatment when feasible. Preoperative α-adrenergic blockade reduces surgical morbidity. Aggressive metastatic PPGL benefits from systemic chemotherapy, while milder cases can be managed with radionuclides. Short-term postoperative follow-up evaluates the adequacy of resection. Long-term follow-up assesses the risk of recurrence or metastasis. Asymptomatic carriers and their families can benefit from surveillance, with intervals depending on the specific gene mutation. Trials primarily focusing on targeted therapy and radionuclides are currently active. A multidisciplinary approach, correct timing, and personalization are key for successful PPGL management.

[Metastatic risk factors in pheochromocytoma/paraganglioma]

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

[French recommendations for malignant pheochromocytomas and paragangliomas by the national ENDOCAN-COMETE network]

Pheochromocytomas and paragangliomas are rare neuroendocrine tumors, developed respectively in the adrenal medulla and in extra-adrenal locations. Their malignancy is defined by the presence of distant metastases. Forty percent of them are inherited and can be part of different hereditary syndromes. Their management is ensured in France by the multidisciplinary expert centers of the ENDOCAN-COMETE national network "Cancers of the Adrenal gland", certified by the National Cancer Institute and discussed within multidisciplinary team meetings. The diagnostic and therapeutic work-up must be standardized, based on an expert analysis of clinical symptoms, hormonal biological secretions, genetics, morphological and specific metabolic imaging. In the context of a heterogeneous survival sometimes beyond seven to ten years, therapeutic intervention must be justified. This is multidisciplinary and relies on surgery, interventional radiology, external or internal radiotherapy and medical treatments such as sunitinib or dacarbazine and temodal chemotherapy. The personalized approach based on functional imaging fixation status and genetics is progressing despite the extreme rarity of this disease.

Reduced uptake pattern on 68 Ga-DOTATATE-scan may indicate necrosis predicting aggressive behavior in pheochromocytoma and paragangliomas (PPGLs)

BACKGROUND

Predicting malignancy among pheochromocytoma paragangliomas (PPGLs) remains a challenge, with only limited understanding of the clinical and molecular characteristics. It has been suggested that reduced avidity of a PPGL on 68 Ga-DOTATATE PET/CT could be a sign of not only altered metabolic activity, but also of increased biologic aggressiveness, possibly due to loss of SSTR-expression.

DESIGN

Retrospective cohort review.

PATIENTS AND MEASUREMENTS

Thirty-seven patients who underwent treatment for PPGL at a tertiary institution over the period 2010-2022, had their biochemical, radiological, and clinicopathological variables collected.

RESULTS

Five of 37 (13%) patients (5 males) with a mean age of 42 years were found to have malignant PPGLs. The mean size of the tumors were 5.4 cm, with 4 located in the paraaortic area and 1 in right adrenal. Functional imaging with 68 Ga-DOTATATE PET/CT showed a mean SUVmax of 4.5. Four of 5 patients underwent open resection of the tumors under general anesthesia following preoperative alpha blockade with oral phenoxybenzamine. The mean PASS score of the excised tumors was 5.5 in keeping with biologically aggressive tumors, with evidence of necrosis. All but 1 patient had germline SDHB-mutation (Deletion Exon 1). Postintervention after a mean follow-up of 31 months, 2 of 5 (40%) patient developed spinal metastasis and 1 patients (25%) died of cardiac complications.

CONCLUSION

A non-highly avid PPGL on DOTATE scan should be considered as possibly having necrosis of tumors indicating a more aggressive tumor-biology. There might be a subgroup of patients in whom FDG-PET scan should be considered to gain additional information.

Dissecting a diagnostic enigma: Hypertension in a young patient from an organ of Zuckerkandl paraganglioma

Hypertension in young patients can mask rare conditions like paragangliomas, especially in the absence of conventional symptoms. A comprehensive diagnostic evaluation and multidisciplinary approach are crucial for optimal management and outcomes.

Image-Guided Precision Medicine in the Diagnosis and Treatment of Pheochromocytomas and Paragangliomas

In this comprehensive review, we aimed to discuss the current state-of-the-art medical imaging for pheochromocytomas and paragangliomas (PPGLs) diagnosis and treatment. Despite major medical improvements, PPGLs, as with other neuroendocrine tumors (NETs), leave clinicians facing several challenges; their inherent particularities and their diagnosis and treatment pose several challenges for clinicians due to their inherent complexity, and they require management by multidisciplinary teams. The conventional concepts of medical imaging are currently undergoing a paradigm shift, thanks to developments in radiomic and metabolic imaging. However, despite active research, clinical relevance of these new parameters remains unclear, and further multicentric studies are needed in order to validate and increase widespread use and integration in clinical routine. Use of AI in PPGLs may detect changes in tumor phenotype that precede classical medical imaging biomarkers, such as shape, texture, and size. Since PPGLs are rare, slow-growing, and heterogeneous, multicentric collaboration will be necessary to have enough data in order to develop new PPGL biomarkers. In this nonsystematic review, our aim is to present an exhaustive pedagogical tool based on real-world cases, dedicated to physicians dealing with PPGLs, augmented by perspectives of artificial intelligence and big data.

Metastatic paraganglioma presenting with spinal cord compression requiring urgent surgery

We report a rare case of a functional bladder paraganglioma diagnosed in a young man who presented with acute compressive thoracic myelopathy secondary to vertebral metastasis. A histological diagnosis of a metastatic paraganglioma was made following biopsy of a rib lesion. CT revealed a lesion in the inferior wall of the bladder, which demonstrated avid uptake on 68Ga-DOTATATE PET/CT. Serum metanephrine levels were more than 40 times the upper limit of normal. The patient was hypertensive and treatment with doxazosin was initiated. In view of neurological deterioration, he required urgent spinal decompression to preserve neurological function and prevent permanent paraplegia. Despite inadequate alpha-blockade, surgery was successful, and the perioperative course was uneventful. Alpha-blockade was subsequently optimised. Treatment with cyclophosphamide, vincristine and dacarbazine was started but, in view of disease progression, treatment was subsequently changed to sunitinib.

Reduced Risk of Corporal Tumors in Patients With Head and Neck Paragangliomas With p.Pro81Leu Mutations

OBJECTIVE

Patients with head and neck paragangliomas who are positive for the SDHD p.Pro81Leu (P81L) mutation are thought to have a distinct phenotype from other SDHx mutations, but few studies have focused on this mutation. The objective of this study was to determine the hazard of developing a second primary, metastatic, or recurrent paraganglioma in SDHx patients with or without P81L.

STUDY DESIGN

Retrospective chart review of 60 patients with head and neck paragangliomas and genetic testing, followed for a median of 9 years.

SETTING

Single academic medical center.

METHODS

Univariable Cox proportional hazards regression evaluated second primary and recurrent paragangliomas in patients with SDHD P81L, SDHx non-P81L, and nonhereditary paraganglioma.

RESULTS

This series comprised 31 patients without SDHx, 14 with SDHD P81L, and 15 with other SDHx mutations. At a median 9 years of follow-up, corporal (not head and neck) second primary paragangliomas occurred in 31% of patients with SDHx non-P81L mutations, compared with 0% and 4% of patients with SDHD P81L and without SDHx mutations, respectively. Second corporal paragangliomas were more likely in patients with SDHx non-P81L mutations than in those without a mutation (hazard ratio = 5.461, 95% confidence interval: 0.596-50.030, p = .13).

CONCLUSION

This is the first study to report a lower likelihood of corporal tumors for patients with head and neck paragangliomas with SDH mutations positive for P81L. Larger studies are needed to determine if head and neck paraganglioma patients with P81L qualify for less intensive imaging surveillance to screen for second primary paragangliomas outside the head and neck.

Can Superoxide Anions Predict the Malignant Potential of Carotid body Tumor? - A Pilot Study

Currently, there is no consensus on estimating the malignant potential of Carotid Body Tumor (CBT) and the only way to predict a metastatic CBT is through DOTANOC Positron Emission Tomography (PET) scan. There is a well-established correlation between CBT and superoxide anions inside tumor cells. The purpose of this pilot study was to measure superoxide anions inside CBT cells and find if these can be used as marker to predict malignant potential of CBT. The results were also co-related with findings of DOTANOC PET scan retrospectively. The CBT tissue from 10 patients was stained using a fluorogenic dye and superoxide anions were measured by analysis of fluorescent image. The patients were divided into two groups - First group with four patients having potentially malignant CBT based upon clinico-surgical characteristics and second group with the rest of the six patients. It was seen that the superoxide anions were highest in the first group which included patients with metastatic carotid body tumor, patients with multiple paragangliomas and patient with positive family history (p = 0.011). The same patients also had metastasis and multiple tumors detected on DOTANOC PET scan. It was concluded that measuring superoxide anions in excised tumor tissue can be used to estimate malignant potential of CBT and can identify patients who truly require DOTANOC PET scan; without affecting the treatment, as it is an expensive investigation involving ionizing radiation and may not be available in all centres.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03623-6.

Surgical management of recurrent and extra-adrenal pheochromocytomas requiring vascular resection and reconstruction

This case series highlights that extra-adrenal and recurrent pheochromocytomas can require en bloc vascular resection to achieve negative margins. Through this series of cases performed in a multidisciplinary fashion, we aim to highlight the technical aspects of these cases that can add to their complexity. Vascular invasion alone should not preclude an otherwise feasible oncologic resection.

Global trends and current status in pheochromocytoma: a bibliometric analysis of publications in the last 20 years

Objective

Pheochromocytoma is a rare catecholamine-producing neuroendocrine tumour originating from the chromaffin cells of the adrenal medulla or extra-adrenal paraganglia. However, there are few bibliometric studies on Pheochromocytoma. Therefore, this study was employed to summarize the global trends and current status in pheochromocytoma by bibliometric analysis.

Materials and methods

The Web of Science (WOS) core collection database was searched for publications relating to pheochromocytoma from 2001 to 2021. Bibliometric analysis was used to examine the data, and Microsoft Excel was utilized to create bar graphs. In addition, VOSviewer was used to carry out co-authorship analysis, co-citation analysis and co-occurrence analysis. CiteSpace was used to analyze the keywords citation bursts.

Results

A total of 8,653 publications published in 1,806 journals by 38,590 authors in 6,117 organizations from 100 countries/regions were included in our study. Among them, USA was the leading countries in terms of total publications and sum of time cited, whereas Eunice Kennedy Shriver Natl Inst Child Hlth & Hum was the leading institutions. The main publications for pheochromocytoma-related articles were Journal of clinical endocrinology &metabolism. Pacak karel and Eisenhofer Graeme were the main contributing authors. The studies on pheochromocytoma could be grouped into five clusters: Treatment, Mechanism, Etiology, Radiology and Hormones study. Moreover, the radiology study, etiology study and some specific keywords such germlines mutation, mesenchymal stem-cells, autophagy, neuroinflammation, neurotoxicity, and hemodynamic instability, may become the hot spots of future.

Conclusion

Although the number of articles on pheochromocytoma has fluctuated slightly over the past 20 years, there has been an overall upward trend. In general, precision medicine research on pheochromocytoma, especially metastatic pheochromocytoma, in terms of diagnosis, treatment, and etiology will be a hot research topic in the future. This study helps to understand the research perspectives, hot spots and trends of pheochromocytoma and provide new insight and a basis for future pheochromocytoma research quickly.

Platelet-Lymphocyte and Neutrophil-Lymphocyte Ratios Are Prognostic Markers for Pheochromocytomas and Paragangliomas

CONTEXT

Preoperative inflammatory markers, such as the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and lymphocyte-monocyte ratio (LMR), have recently been proposed as prognostic markers in different tumors. However, their predictive values in patients with pheochromocytomas and paragangliomas (PPGLs) are uncertain.

OBJECTIVE

This study aimed to investigate the prognostic significance of inflammatory biomarkers in PPGL patients.

METHODS

Data from 1247 consecutive PPGL patients between 2002 and 2020 were evaluated. The preoperative inflammatory markers were evaluated. The prognostic roles were identified by X-tile software, Kaplan-Meier curves, and Cox regression models.

RESULTS

A total of 728 patients were included in the analysis, with a median follow-up of 63 months (IQR, 31-111 months); 31 individuals died, 28 patients developed metastases, and 12 patients developed recurrence. Our study showed that deaths were observed significantly more frequently in patients with high NLR(≥3.5) and high PLR (≥217.4) than those with low NLR (<3.5) (P = .003) and low PLR (<217.4) (P = .005). Elevated NLR (≥3.5) and elevated PLR (≥217.4) was significantly associated with decreased overall survival (OS) (P = .005), and elevated PLR (≥238.3) was significantly associated with decreased metastasis-free survival (MFS) (P = .021). Cox models illustrated that NLR and PLR were independent prognostic factors for OS, and PLR was an independent prognostic factor for MFS.

CONCLUSION

Both elevated NLR and PLR are associated with poor prognosis in PPGLs. They are convenient predictive markers that could be used in daily clinical practice.

Diagnosis, Genetics, and Management of 24 Patients With Cardiac Paragangliomas: Experience From a Single Center

Context

Paragangliomas located within the pericardium represent a rare yet challenging clinical situation.

Objective

The current analysis aimed to describe the clinical characteristics of cardiac paragangliomas, with emphasis on the diagnostic approach, genetic background, and multidisciplinary management.

Methods

Twenty-four patients diagnosed with cardiac paraganglioma (PGL) in Peking Union Medical College Hospital, Beijing, China, between 2003 and 2021 were identified. Clinical data was collected from medical record. Genetic screening and succinate dehydrogenase subunit B immunohistochemistry were performed in 22 patients.

Results

The median age at diagnosis was 38 years (range 11-51 years), 8 patients (33%) were females, and 4 (17%) had familial history. Hypertension and/or symptoms related to catecholamine secretion were present in 22 (92%) patients. Excess levels of catecholamines and/or metanephrines were detected in 22 (96%) of the 23 patients who have completed biochemical testing. Cardiac PGLs were localized with 131I-metaiodobenzylguanidine scintigraphy in 11/22 (50%), and 99mTc-hydrazinonicotinyl-tyr3-octreotide scintigraphy in 24/24 (100%) patients. Genetic testing identified germline SDHx mutations in 13/22 (59%) patients, while immunohistochemistry revealed succinate dehydrogenase (SDH) deficiency in tumors from 17/22 (77%) patients. All patients were managed by a multidisciplinary team through medical preparation, surgery, and follow-up. Twenty-three patients received surgical treatment and perioperative death occurred in 2 cases. Overall, 21 patients were alive at follow-up (median 7.0 years, range 0.6-18 years). Local recurrence or metastasis developed in 3 patients, all of whom had SDH-deficient tumors.

Conclusion

Cardiac PGLs can be diagnosed based on clinical manifestations, biochemical tests, and appropriate imaging studies. Genetic screening, multidisciplinary approach, and long-term follow-up are crucial in the management of this disease.