Clinical risk factors for malignancy and overall survival in patients with pheochromocytomas and sympathetic paragangliomas: primary tumor size and primary tumor location as prognostic indicators

Management of Pheochromocytomas and Paragangliomas

Pheochromocytomas and paragangliomas are distinctive neuroendocrine tumors which frequently produce excess catecholamines with resultant cardiovascular morbidity. These tumors have a strong genetic component, with up to 40% linked to hereditary pathogenic variants; therefore, germline genetic testing is recommended for all patients. Surgical resection offers the only potential cure in the case of localized disease. Given the potential for catecholaminergic crises, appropriate perioperative management is crucial, and all patients should undergo alpha-adrenergic blockade before resection. Therapeutic options for metastatic disease are limited and include surgical debulking, radiopharmaceutical therapies, and conventional chemotherapy.

Weakly supervised detection of pheochromocytomas and paragangliomas in CT using noisy data

Pheochromocytomas and Paragangliomas (PPGLs) are rare adrenal and extra-adrenal tumors that have metastatic potential. Management of patients with PPGLs mainly depends on the makeup of their genetic cluster: SDHx, VHL/EPAS1, kinase, and sporadic. CT is the preferred modality for precise localization of PPGLs, such that their metastatic progression can be assessed. However, the variable size, morphology, and appearance of these tumors in different anatomical regions can pose challenges for radiologists. Since radiologists must routinely track changes across patient visits, manual annotation of PPGLs is quite time-consuming and cumbersome to do across all axial slices in a CT volume. As such, PPGLs are only weakly annotated on axial slices by radiologists in the form of RECIST measurements. To ameliorate the manual effort spent by radiologists, we propose a method for the automated detection of PPGLs in CT via a proxy segmentation task. Weak 3D annotations (derived from 2D bounding boxes) were used to train both 2D and 3D nnUNet models to detect PPGLs via segmentation. We evaluated our approaches on an in-house dataset comprised of chest-abdomen-pelvis CTs of 255 patients with confirmed PPGLs. On a test set of 53 CT volumes, our 3D nnUNet model achieved a detection precision of 70% and sensitivity of 64.1%, and outperformed the 2D model that obtained a precision of 52.7% and sensitivity of 27.5% (p< 0.05). SDHx and sporadic genetic clusters achieved the highest precisions of 73.1% and 72.7% respectively. Our state-of-the art findings highlight the promising nature of the challenging task of automated PPGL detection.

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.

Analysis of clinical and pathological characteristics of retroperitoneal paraganglioma and associated prognostic factors

BACKGROUND AND OBJECTIVES

The aim of this study is to explore the long-term prognostic risk factors associated with patients diagnosed with retroperitoneal paraganglioma (RPGL) and examine their clinical and pathological characteristics.

METHODS

Expressions of biomarkers were identified using immunohistochemistry (IHC) and case databases were retrospectively searched. Survival analysis was performed using Kaplan-Meier and Cox risk regression to identify the factors that influence the postoperative progression-free survival of patients with RPGL.

RESULTS

A total of 105 patients, most of whom had tumors situated in the paraaortic region, and whose average tumor size was 8.6 cm, were enrolled in this study. The average follow-up duration was 51 months, with a mortality rate of 19% and a recurrence and metastasis rate of 41.9%. Tumors were assessed using the modified Grading system for Adrenal Pheochromocytoma and Paraganglioma (GAPP), and SDHB, S-100, and Ki-67 were stained using IHC in all cases. Out of the total cases examined, negative in SDHB expression were observed in 18.1% of cases, S-100 expression was negative in 36.2% of cases, and endovascular tumor enboluswas present in approximately 25.7% of cases. The results of the univariate analysis indicated that several factors significantly influenced the progression-free survival of patients with PGL as follow: maximum tumor diameter (>5.5 cm), tumor morphological features, tumor grading (modified GAPP score > 6), SDHB negative, S-100 negative, and expression of proliferation index Ki-67 (>3%) (X2 = 4.217-27.420, p < 0.05). The results of the multivariate analysis indicated that negative of S-100 (p = 0.021) and SDHB (p = 0.038), as well as intravascular tumor thrombus (p = 0.047) expression were independent risk factors for progression-free survival in patients.

CONCLUSION

RPGL is characterized by diverse biological features and an elevated susceptibility to both recurrence and metastasis. Both SDHB and S-100 can be employed as traditional IHC indicators to predict the metastatic risk of PGL, whereas the tumor histomorphology-endovascular tumor enbolus assists in determining the metastasis risk of RPGL.

Preoperative prediction of metastatic pheochromocytoma and paraganglioma using clinical, genetic, and biochemical markers: A cohort study

BACKGROUND

The prevalence of metastatic pheochromocytoma and paraganglioma (PPGL) is approximately 15%-20%. Although there are indicators to assess metastatic risks, none of them predict metastasis reliably. Therefore, we aimed to develop and validate a scoring system using clinical, genetic, and biochemical risk factors to preoperatively predict the metastatic risk of PPGL.

METHODS

In the cross-sectional cohort (n = 180), clinical, genetic, and biochemical risk factors for metastasis were identified using multivariate logistic regression analysis, and a novel scoring system was developed. The scoring system was validated and compared with the age, size of tumor, extra-adrenal location, and secretory type (ASES) score in the longitudinal cohort (n = 114).

RESULTS

In the cross-sectional cohort, pseudohypoxia group-related gene variants (SDHB, SDHD, or VHL), methoxytyramine >0.16 nmol/L, and tumor size >6.0 cm were independently associated with metastasis after multivariate logistic regression. Using them, the gene variant, methoxytyramine, and size of tumor (GMS) score were developed. In the longitudinal cohort, Harrell's concordance index of the GMS score (0.873, 95% confidence interval [CI]: 0.738-0.941) was higher than that of the ASES score (0.713, 95% CI: 0.567-0.814, p = 0.007). In the longitudinal cohort, a GMS score ≥2 was significantly associated with a higher risk of metastasis (hazard ratio = 25.07, 95% CI: 5.65-111.20). A GMS score ≥2 (p < 0.001), but not ASES score ≥2 (p = 0.090), was associated with shorter progression-free survival.

CONCLUSION

The GMS scoring system, which integrates gene variant, methoxytyramine level, and tumor size, provides a valuable preoperative approach to assess metastatic risk in PPGL.

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.

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.

Cabozantinib in patients with unresectable and progressive metastatic phaeochromocytoma or paraganglioma (the Natalie Trial): a single-arm, phase 2 trial

BACKGROUND

Metastatic phaeochromocytomas and paragangliomas (MPPGs) are orphan diseases. Up to 50% of MPPGs are associated with germline pathogenic variants of the SDHB gene. These tumours and many non-familial MPPGs exhibit a phenotype that is characterised by abnormal angiogenesis. We aimed to assess the activity and safety of cabozantinib, an antiangiogenic multi-tyrosine kinase inhibitor, in patients with MPPGs.

METHODS

The Natalie Trial is a single-arm, phase 2 clinical trial being conducted at The University of Texas MD Anderson Cancer Center (Houston, TX, USA). Patients aged 18 years or older with histologically confirmed, progressive, and unresectable MPPGs, with an Eastern Cooperative Oncology Group performance status of 0-2, were treated with oral cabozantinib 60 mg/day. The primary endpoint was the investigator-assessed overall response rate per the Response Evaluation Criteria in Solid Tumours version 1.1 criteria. All outcomes were assessed in all evaluable participants who received any amount of study treatment. The trial is registered with ClinicalTrials.gov (NCT02302833) and is active but not recruiting.

FINDINGS

From March 10, 2015, to May 11, 2021, 17 patients (13 male participants and four female participants) were enrolled. The median follow-up was 25 months (IQR 18-49). The overall response rate was 25·0% (95% CI 7·3-52·4; four of 16 patients). Seven grade 3 adverse events were reported in six patients, including single cases of hand-and-foot syndrome, hypertension, rectal fistula, QT prolongation, and asymptomatic hypomagnesaemia, and two cases of asymptomatic elevations of amylase and lipase. There were no grade 4 adverse events and no patient died on-study.

INTERPRETATION

Cabozantinib shows promising activity in patients with MPPGs.

FUNDING

Team NAT Foundation, Margaret Cazalot, and Clarence P Cazalot.

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.

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.

177 Lu-DOTATATE in the Treatment of Recurrent Pheochromocytoma With Multiple Metastases

ABSTRACT

The treatment of metastatic pheochromocytoma is challenging. We report a case of a woman with recurrent pheochromocytoma with multiple metastases who achieved excellent response after 4 cycles of 177 Lu-DOTATATE therapy. She did not experience any observable adverse effects. Her disease was still stable 6 months after the fourth cycle of treatment.

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.

Non‑functional paraganglioma: A case report

Paraganglioma (PGL) usually presents as the elevation of blood pressure and metabolic changes in patients, and its common symptoms are persistent or paroxysmal hypertension. However, some patients have no typical clinical symptoms, such as patients with non-functional PGL. Therefore, the present study reviewed the literature and summarized the present rare case to provide more accurate and in-depth help for clinical diagnosis and comprehensive treatment. The case was a 64-year-old female with epigastrium malaise for 1 year and aggravation for 7 days. Contrast-enhanced CT revealed that the soft tissue of the irregular mass was in the front of the kidney on the right abdomen with a clear boundary and the size was ~6.5x5.4x6.6 cm. Large vessels were observed in the interior and edge of the lesion. The present study prepared for retroperitoneal tumour resection according to the diagnosis of PGL. After the operation, the patient recovered smoothly and was discharged from the hospital. As of March 2023, the general condition of the patient is good.

Bladder paraganglioma: Case report and review of the literature

Pheochromocytoma is a tumor that originates from the chromaffin cells of the adrenal medulla and is responsible for the production of catecholamines. However, when it occurs outside the adrenal glands, it is called a paraganglioma and accounts for 10%-15% of cases. In this report, we present the case of a 27-year-old male patient with a history of hypertension, who presented hematuria and dizziness on urination with a diagnosis of bladder paraganglioma. Contrast-enhanced computed tomography revealed the presence of a bladder tumor. Bladder paraganglioma is a rare condition, and understanding possible imaging findings is crucial to raising suspicion of this diagnosis and expanding our knowledge of this rare disease.

Local recurrence and metastatic disease in pheochromocytomas and sympathetic paragangliomas

Purpose

To evaluate the rate of recurrence among patients with pheochromocytomas and sympathetic paragangliomas (PGLs; together PPGLs) and to identify predictors of recurrence (local recurrence and/or metastatic disease).

Methods

This retrospective multicenter study included information of 303 patients with PPGLs in follow-up in 19 Spanish tertiary hospitals. Recurrent disease was defined by the development of local recurrence and/or metastatic disease after initial complete surgical resection.

Results

A total of 303 patients with PPGLs that underwent 311 resections were included (288 pheochromocytomas and 15 sympathetic PGLs). After a median follow-up of 4.8 years (range 1-19), 24 patients (7.9%) had recurrent disease (3 local recurrence, 17 metastatic disease and 4 local recurrence followed by metastatic disease). The median time from the diagnosis of the PPGL to the recurrence was of 11.2 months (range 0.5-174) and recurrent disease cases distributed uniformly during the follow-up period. The presence of a pathogenic variant in SDHB gene (hazard ratio [HR] 13.3, 95% CI 4.20-41.92), higher urinary normetanephrine levels (HR 1.02 per each increase in standard deviation, 95% CI 1.01-1.03) and a larger tumor size (HR 1.01 per each increase in mm, 95% CI 1.00-1.02) were independently associated with disease recurrence.

Conclusion

The recurrence of PPGLs occurred more frequently in patients with SDHB mutations, with larger tumors and with higher urinary normetanephrine levels. Since PPGL recurrence may occur at any time after the initial PPGL diagnosis is performed, we recommend performing a strict follow-up in all patients with PPGLs, especially in those patients with a higher risk of recurrent disease.

[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.

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.

Prediction of metastatic pheochromocytoma and paraganglioma: a machine learning modelling study using data from a cross-sectional cohort

BACKGROUND

Pheochromocytomas and paragangliomas have up to a 20% rate of metastatic disease that cannot be reliably predicted. This study prospectively assessed whether the dopamine metabolite, methoxytyramine, might predict metastatic disease, whether predictions might be improved using machine learning models that incorporate other features, and how machine learning-based predictions compare with predictions made by specialists in the field.

METHODS

In this machine learning modelling study, we used cross-sectional cohort data from the PMT trial, based in Germany, Poland, and the Netherlands, to prospectively examine the utility of methoxytyramine to predict metastatic disease in 267 patients with pheochromocytoma or paraganglioma and positive biochemical test results at initial screening. Another retrospective dataset of 493 patients with these tumors enrolled under clinical protocols at National Institutes of Health (00-CH-0093) and the Netherlands (PRESCRIPT trial) was used to train and validate machine learning models according to selections of additional features. The best performing machine learning models were then externally validated using data for all patients in the PMT trial. For comparison, 12 specialists provided predictions of metastatic disease using data from the training and external validation datasets.

FINDINGS

Prospective predictions indicated that plasma methoxytyramine could identify metastatic disease at sensitivities of 52% and specificities of 85%. The best performing machine learning model was based on an ensemble tree classifier algorithm that used nine features: plasma methoxytyramine, metanephrine, normetanephrine, age, sex, previous history of pheochromocytoma or paraganglioma, location and size of primary tumours, and presence of multifocal disease. This model had an area under the receiver operating characteristic curve of 0·942 (95% CI 0·894-0·969) that was larger (p<0·0001) than that of the best performing specialist before (0·815, 0·778-0·853) and after (0·812, 0·781-0·854) provision of SDHB variant data. Sensitivity for prediction of metastatic disease in the external validation cohort reached 83% at a specificity of 92%.

INTERPRETATION

Although methoxytyramine has some utility for prediction of metastatic pheochromocytomas and paragangliomas, sensitivity is limited. Predictive value is considerably enhanced with machine learning models that incorporate our nine recommended features. Our final model provides a preoperative approach to predict metastases in patients with pheochromocytomas and paragangliomas, and thereby guide individualised patient management and follow-up.

FUNDING

Deutsche Forschungsgemeinschaft.

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.

Pheochromocytoma presenting with upper abdominal pain and hypertensive crisis: A case report

Pheochromocytoma (PHEO) is a rare and complex molecularly driven endocrine disease that can present with a variety of clinical manifestations, including paroxysmal hypertension, episodic anxiety, tremors, devastating acute heart failure and acute pulmonary edema. The variety of PHEO-related symptoms increase the difficulty of identifying and diagnosing PHEO. We reported a case of a 27-year-old Chinese male was diagnosed PHEO by CT scan because of upper abdominal pain. The patient complicated with hypertensive crisis and headache following his admission, and he was underwent adrenal tumor surgical resection by carrying out appropriate clinical, laboratory and radiological imaging. Thus, the patient's PHEO-related symptoms were relieved and the blood pressure returned to normal, and discharged from the hospital with a follow-up plan. Although the PEHO-related symptoms are varied and difficult to diagnose, CT examination can be used for the preliminary detection and diagnosis. This case report emphasizes the importance of considering PHEO by CT scan and atypical symptoms, which help others better understand PHEO for early detection and timely surgical treatment to reduce catecholamine-related complications.

Cytoplasmic HIF-2α as tissue biomarker to identify metastatic sympathetic paraganglioma

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare neuroendocrine tumors. PGLs can further be divided into sympathetic (sPGLs) and head-and-neck (HN-PGLs). There are virtually no treatment options, and no cure, for metastatic PCCs and PGLs (PPGLs). Here, we composed a tissue microarray (TMA) consisting of 149 PPGLs, reflecting clinical features, presenting as a useful resource. Mutations in the pseudohypoxic marker HIF-2α correlate to an aggressive tumor phenotype. We show that HIF-2α localized to the cytoplasm in PPGLs. This subcompartmentalized protein expression differed between tumor subtypes, and strongly correlated to proliferation. Half of all sPGLs were metastatic at time of diagnosis. Cytoplasmic HIF-2α was strongly expressed in metastatic sPGLs and predicted poor outcome in this subgroup. We propose that higher cytoplasmic HIF-2α expression could serve as a useful clinical marker to differentiate paragangliomas from pheochromocytomas, and may help predict outcome in sPGL patients.

Peptide receptor radionuclide therapy in advanced Pheochromocytomas and Paragangliomas: a systematic review and meta-analysis

Objective

Peptide receptor radionuclide therapy (PRRT) for advanced pheochromocytomas and paragangliomas (PPGLs) has received increasing attention. The purpose of this article is to evaluate the efficacy and safety of PRRT in patients with metastatic or inoperable PPGLs by meta-analysis.

Methods

A literature search was conducted in PubMed, Embase, Scopus, and Cochrane Library databases up to November 2022. All articles on PRRT for PPGLs were searched, and appropriate data were included for analysis. The measures evaluated included objective response rate (ORR), disease control rate (DCR), clinical response rate, biochemical response rate, progression-free survival (PFS), overall survival (OS), and adverse events. Statistical analysis was performed using Stata 16.0 and the R programming language, data were combined using a random-effects model, and the results were presented using forest plots.

Results

A total of 20 studies with 330 patients were included in the analysis. The results showed that ORR and DCR were 20.0% (95% CI: 12.0%-28.0%) and 90.0% (95% CI: 85.0%-95.0%), respectively. Clinical and biochemical responses were 74.9% (95% CI: 56.3%-90.2%) and 69.5% (95%CI: 40.2%-92.9%). Median PFS and median OS were 31.79 (95% CI:21.25-42.33) months and 74.30 (95% CI: 0.75-147.84) months, respectively. Any grade of hematotoxicity and nephrotoxicity occurred in 22.3% (95% CI:12.5%-33.5%) and 4.3% (95% CI:0.2%-11.4%) patients. Grade 3-4 hemotoxicity occurred in 4.3% (95% CI:0.2%-11.4%) and grade 3-4 nephrotoxicity in 4/212 patients. Additionally, Treatment was discontinued in 9.0% (95% CI: 0.5%-23.3%) patients and one patient died as a result of a toxicity.

Conclusion

Patients with metastatic or inoperable PPGLs can be effectively treated with PRRT, and it has a favorable safety profile.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42022359232.

Multimodality Imaging Appearance of Intrapericardial Paragangliomas

Paragangliomas are neuroendocrine tumors of the sympathetic and parasympathetic nervous system that originate from neural crest cells. Less than 1% of paragangliomas are found in the heart, originating from intrinsic cardiac ganglia cells in the posterior wall the atria, atrioventricular groove, and along the root of the great vessels. A 10-year review of our institution's database identified nine patients who had documented intrapericardial paragangliomas. We describe the multimodality imaging appearance of these tumors. The most common findings include embedment and wrapping around the great vessels and atrioventricular groove within the confines of the pericardium, markedly avid heterogeneous enhancement, distinct engorged neovascularization, and in large lesions, central low attenuation areas compatible with hemorrhage, necrosis, or cystic degeneration.

Fumarate Hydratase Variants and Their Association With Paraganglioma/Pheochromocytoma

OBJECTIVE

To clarify the link between germline variants in fumarate hydratase (FH), hereditary leiomyomatosis and renal cell cancer (HLRCC), and paraganglioma (PGL) and pheochromocytoma (PCC) we utilize a well-annotated hereditary cancer testing database.

METHODS

Records of 120,061 patients receiving germline testing were obtained. FH variants were classified into 4 categories: autosomal dominant (AD) HLRCC variants, autosomal recessive (AR) fumarase deficiency (FMRD), variants, previously reported as PGL/PCC FH variants, and variants of unknown significance (VUS) not previously associated with PGL/PCC (NPP-VUS). Rates of PGL/PCC were compared with those with negative genetic testing.

RESULTS

About 1.3% of individuals carried FH variants which were more common among individuals with PGL/PCC compared to those without (3.1% vs 1.3%, P < .0001). PGL/PCC rates were higher among individuals with PGL/PCC FH variants compared to those with negative genetic testing (22.2% vs 0.9%, P < .0001). Neither AD HLRCC variants (0.3% vs 0.9%, P = .35) nor AR FMRD variants (1.4% vs 0.9%, P = .19) carried an increased prevalence of PGL/PCC. An increased prevalence of PGL/PCC was detected in those with NPP-VUS (2.0% vs 0.9%, P = .0023).

CONCLUSIONS

Certain FH variants confer an increased risk of PGL/PCC, but not necessarily HLRCC. While universal screening for PGL/PCC among all individuals with FH variants does not appear warranted, it should be considered in select high-risk PGL/PCC FH variants.

Long-Term Outcomes after Surgery for Pheochromocytoma and Sympathetic Paraganglioma

BACKGROUND

The prognosis of pheochromocytoma and sympathetic paraganglioma (PHEO/sPGL) is difficult to predict at the time of diagnosis and long-term follow-up data are scarce, especially for apparently benign and sporadic variants. The aim of the study was to analyze the long-term outcomes in PHEO/sPGL patients.

METHODS

A monocentric series of 170 patients who underwent surgery for PHEO/sPGL was analyzed.

RESULTS

The study cohort included 91 female and 79 males with a median age of 48 years (range 6-83). The majority of PHEO/sPGL cases were considered apparently benign at the time of diagnosis; evident malignant behavior was found in 5% of cases. The overall 10-year risk of recurrence was 13%, but it rose up to 33% at 30 years. The risk of new tumor recurrence was higher in patients with hereditary tumors, but the risk was still significant in patients with apparently sporadic variants (20-year risk: 38% vs. 6.5%, respectively; p < 0.0001). The risk of metastatic recurrence was higher in patients with locally aggressive tumors at diagnosis, but the risk was present also in apparently benign variants (5-year risk: 100% vs. 1%, respectively; p < 0.0001).

CONCLUSIONS

Lifelong follow-up is required not only for hereditary PHEO/sPGL but also for apparently benign and sporadic tumors at diagnosis because of the risk of long-term recurrent disease.

Management of pheochromocytomas and paragangliomas: Review of current diagnosis and treatment options

Pheochromocytomas (PCCs) are rare neuroendocrine tumors derived from the chromaffin cells of the adrenal medulla. When these tumors have an extra-adrenal location, they are called paragangliomas (PGLs) and arise from sympathetic and parasympathetic ganglia, particularly of the para-aortic location. Up to 25% of PCCs/PGLs are associated with inherited genetic disorders. The majority of PCCs/PGLs exhibit indolent behavior. However, according to their affiliation to molecular clusters based on underlying genetic aberrations, their tumorigenesis, location, clinical symptomatology, and potential to metastasize are heterogenous. Thus, PCCs/PGLs are often associated with diagnostic difficulties. In recent years, extensive research revealed a broad genetic background and multiple signaling pathways leading to tumor development. Along with this, the diagnostic and therapeutic options were also expanded. In this review, we focus on the current knowledge and recent advancements in the diagnosis and treatment of PCCs/PGLs with respect to the underlying gene alterations while also discussing future perspectives in this field.

Functional Imaging Evidence of Tumor Response to High-Specific-Activity 131 I-MIBG Therapy in an 84-Year-Old Patient With Metastatic Pheochromocytoma/Paraganglioma

ABSTRACT

An 84-year-old man with history of metastatic pheochromocytoma/paraganglioma (mPPGL) received surgery 13 years ago, with recent biopsy-proven mPPGL in the T11. 123 I-MIBG scan showed MIBG-avid liver and osseous. Given his medical condition and body habitus (weight, 45 kg; height, 140 cm), the patient was treated with high-specific-activity 131 I-MIBG (Azedra) 300 mCi ×2. He tolerated the medication and was totally asymptomatic. Series 123 I-MIBG scan showed good responses till 22 months after the first treatment at the last visit. This is probably the oldest and smallest adult mPPGL patient treated with Azedra and with prolonged good response.

Succinate Dehydrogenase Mutations as Familial Pheochromocytoma Syndromes

It is recognized that a large portion of pheochromocytoma and paraganglioma cases will have an underlying germline mutation, supporting the recommendation for universal genetic testing in all patients with PPGLs. A mutation in succinate dehydrogenase subunit B is associated with increased rates of developing synchronous and/or metachronous metastatic disease. Patients identified with this mutation require meticulous preoperative evaluation, a personalized surgical plan to minimize the risk of recurrence and tumor spread, and lifelong surveillance.

Proposed MIBG Scan-Based Tumor Response Criteria of High-Specific-Activity 131 I-MIBG Therapy in Metastatic Pheochromocytoma/Paraganglioma

ABSTRACT

High-specific-activity 131 I-MIBG (Azedra) is the only Food and Drug Administration-approved therapy for metastatic pheochromocytomas and paragangliomas, which are rare neuroendocrine tumors with limited treatment options. Based on our experience, we proposed here functional imaging-based tumor response criteria for these patient cohorts. Each response category was illustrated with typical sample cases, and clinical correlation was provided.

Biomarker response to high-specific-activity I-131 meta-iodobenzylguanidine in pheochromocytoma/paraganglioma

The objective of this study is to present the complete biomarker response dataset from a pivotal trial evaluating the efficacy and safety of high-specific-activity I-131 meta-iodobenzylguanidine in patients with advanced pheochromocytoma or paraganglioma. Biomarker status was assessed and post-treatment responses were analyzed for catecholamines, metanephrines, and serum chromogranin A. Complete biomarker response (normalization) or partial response, defined as at least 50% reduction from baseline if above the normal range, was evaluated at specified time points over a 12-month period. These results were correlated with two other study objectives: blood pressure control and objective tumor response as per RECIST 1.0. In this open-label, single-arm study, 68 patients received at least one therapeutic dose (~18.5 GBq (~500 mCi)) of high-specific-activity I-131 meta-iodobenzylguanidine. Of the patients, 79% and 72% had tumors associated with elevated total plasma free metanephrines and serum chromogranin A levels, respectively. Best overall biomarker responses (complete or partial response) for total plasma free metanephrines and chromogranin A were observed in 69% (37/54) and 80% (39/49) of patients, respectively. The best response for individual biomarkers was observed 6-12 months following the first administration of high-specific-activity I-131 meta-iodobenzylguanidine. Biochemical tumor marker response was significantly associated with both reduction in antihypertensive medication use (correlation coefficient 0.35; P = 0.006) as well as objective tumor response (correlation coefficient 0.36; P = 0.007). Treatment with high-specific-activity I-131 meta-iodobenzylguanidine resulted in long-lasting biomarker responses in patients with advanced pheochromocytoma or paraganglioma that correlated with blood pressure control and objective response rate. ClinicalTrials.gov number: NCT00874614.

Recurrent Disease in Patients With Sporadic Pheochromocytoma and Paraganglioma

CONTEXT

Long-term follow-up has been recommended for patients with pheochromocytoma or paraganglioma (PPGL) due to potential for recurrent disease. However, the need to follow patients with sporadic PPGL has recently become controversial.

OBJECTIVE

To investigate the prevalence of recurrence among patients with sporadic compared with hereditary PPGL and to identify predictors of recurrence for sporadic disease.

METHODS

This multicenter study included retrospective data from 1127 patients with PPGL. In addition to sex and age at primary tumor diagnosis, clinical information included location, size, and catecholamine phenotype of primary tumors, genetic test results, and subsequent development of recurrent and/or metastatic disease. Patients with sporadic PPGL were defined as those with negative genetic test results.

RESULTS

Prevalence of recurrence among patients with sporadic PPGL (14.7%) was lower (P < 0.001) than for patients with pathogenic variants that activate pseudohypoxia pathways (47.5%), but similar to those with variants that activate kinase pathways (14.9%). Among patients with sporadic recurrent PPGL, 29.1% and 17.7% were respectively diagnosed at least 10 and 15 years after first diagnosis. Multivariable regression analysis showed that a noradrenergic/dopaminergic phenotype (HR 2.73; 95% CI, 1.553-4.802; P < 0.001), larger size (HR 1.82; 95% CI, 1.113-2.962; P = 0.017) and extra-adrenal location (HR 1.79; 95% CI, 1.002-3.187; P = 0.049) of primary tumors were independent predictors of recurrence in sporadic PPGL.

CONCLUSION

Patients with sporadic PPGL require long-term follow-up, as supported by the 14.7% prevalence of recurrent disease, including recurrences at more than 10 years after first diagnosis. The nature of follow-up could be individualized according to tumor size, location, and biochemical phenotype.

SDHB immunohistochemistry for prognosis of pheochromocytoma and paraganglioma: A retrospective and prospective analysis

INTRODUCTION

Pheochromocytomas and paragangliomas (PCC/PGL) are rare neuroendocrine tumors and can secrete catecholamine. Previous studies have found that SDHB immunohistochemistry (IHC) can predict SDHB germline gene mutation, and SDHB mutation is closely associated with tumor progression and metastasis. This study aimed to clarify the potential effect of SDHB IHC as a predictive marker for tumor progression in PCC/PGL patients.

METHODS

We included PCC/PGL patients diagnosed in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from 2002 to 2014 for retrospective analysis and discovered that SDHB (-) staining patients had poorer prognoses. Then we examined SDHB protein expression by IHC on all tumors in the prospective series, which was composed of patients from 2015 to 2020 in our center.

RESULTS

In the retrospective series, the median follow-up was 167 months, and during follow-up, 14.4% (38/264) patients developed metastasis or recurrence, and 8.0% (22/274) patients died. Retrospective analysis revealed that 66.7% (6/9) of participants in the SDHB (-) group and 15.7% (40/255) of those in the SDHB (+) group developed progressive tumors (OR: 10.75, 95% CI: 2.72-52.60, P=0.001), and SDHB (-) was independently associated with poor outcomes after adjusting by other clinicopathological parameters (OR: 11.68, 95% CI: 2.58-64.45, P=0.002). SDHB (-) patients had shorter disease-free survival (DFS) and overall survival (OS) (P<0.001) and SDHB (-) was significantly associated with shorter median DFS (HR: 6.89, 95% CI: 2.41-19.70, P<0.001) in multivariate cox proportional hazard analysis. In the prospective series, the median follow-up was 28 months, 4.7% (10/213) patients developed metastasis or recurrence, and 0.5% (1/217) patient died. For the prospective analysis, 18.8% (3/16) of participants in the SDHB (-) group had progressive tumors compared with 3.6% (7/197) in the SDHB (+) group (RR: 5.28, 95% CI: 1.51-18.47, P=0.009), statistical significance remained (RR: 3.35, 95% CI: 1.20-9.38, P=0.021) after adjusting for other clinicopathological factors.

CONCLUSIONS

Our findings demonstrated patients with SDHB (-) tumors had a higher possibility of poor outcomes, and SDHB IHC can be regarded as an independent biomarker of prognosis in PCC/PGL.

Tumour microenvironment in pheochromocytoma and paraganglioma

Pheochromocytomas and Paragangliomas (Pheo/PGL) are rare catecholamine-producing tumours derived from adrenal medulla or from the extra-adrenal paraganglia respectively. Around 10-15% of Pheo/PGL develop metastatic forms and have a poor prognosis with a 37% of mortality rate at 5 years. These tumours have a strong genetic determinism, and the presence of succinate dehydrogenase B (SDHB) mutations are highly associated with metastatic forms. To date, no effective treatment is present for metastatic forms. In addition to cancer cells, the tumour microenvironment (TME) is also composed of non-neoplastic cells and non-cellular components, which are essential for tumour initiation and progression in multiple cancers, including Pheo/PGL. This review, for the first time, provides an overview of the roles of TME cells such as cancer-associated fibroblasts (CAFs) and tumour-associated macrophages (TAMs) on Pheo/PGL growth and progression. Moreover, the functions of the non-cellular components of the TME, among which the most representatives are growth factors, extracellular vesicles and extracellular matrix (ECM) are explored. The importance of succinate as an oncometabolite is emerging and since Pheo/PGL SDH mutated accumulate high levels of succinate, the role of succinate and of its receptor (SUCNR1) in the modulation of the carcinogenesis process is also analysed. Further understanding of the mechanism behind the complicated effects of TME on Pheo/PGL growth and spread could suggest novel therapeutic targets for further clinical treatments.

Prognostic value of [18F]FDG-PET prior to [131I]MIBG treatment for pheochromocytoma and paraganglioma (PPGL)

OBJECTIVE

Pheochromocytomas and paragangliomas (PPGLs) are rare tumors arising from the neural crest cells that form the sympathetic and parasympathetic nervous systems. Radiotherapy with [¹³¹I]metaiodobenzylguanidine (MIBG) is recommended for unresectable PPGLs. We investigated the usefulness of the metabolic tumor volume (MTV) and total lesion glycolysis (TLG) derived from [¹⁸F]fluorodeoxyglucose-positron emission tomography (FDG-PET) for predicting the prognosis of patients with unresectable PPGL(s) before receiving [¹³¹I]MIBG therapy.

PATIENTS AND METHODS

We retrospectively analyzed the cases of 25 patients with unresectable PPGLs treated with [¹³¹I]MIBG at our hospital between 2001 and 2020. The MTV and TLG were measured in reference to liver accumulation. We divided the patients into two groups based on median values for the maximum standardized uptake value (SUVmax), MTV, and TLG, and evaluated between-group differences using log-rank tests. Cox proportional hazards models were used to determine whether there were significant differences in prognosis with respect to tumor type (pheochromocytoma vs. paraganglioma), site of metastasis, age, past treatment (chemotherapy, external radiation or [¹³¹I]MIBG treatment before the current [¹³¹I]MIBG treatment), urinary catecholamine, SUVmax, MTV, and TLG.

RESULTS

The median follow-up time was 42 months (range 2-136 months). The median overall survival was 63 months. The overall survival (OS) was significantly shorter in the high-MTV group (log-rank test, p = 0.049) and the high-TLG group (p = 0.049), with no significant difference between the high- and low-SUVmax groups (p = 0.19). Likewise, there was no significant difference in prognosis according to pheochromocytoma or paraganglioma, metastasis location, age, or prior chemotherapy. A history of external radiation before [¹³¹I]MIBG treatment was associated with a significantly worse prognosis (hazard ration [HR] = 7.95, p = 0.0018). Urinary adrenaline and noradrenaline were not significant prognostic factors (p = 0.70, p = 0.25, respectively), but urinary dopamine did predict a worse outcome (p = 0.022). There was no increased risk of death for higher SUVmax or TLG (p = 0.63 and 0.057, respectively), but higher MTV did predict a worse outcome (HR = 7.27, p = 0.029).

CONCLUSION

High MTV and high TLG were significantly associated with a poor prognosis after [¹³¹I]MIBG therapy for PPGLs. Other treatment strategies for such patients may need to be explored.

Other Less Prevalent Tumors of the Central Nervous System

The presented tumors in this chapter are somewhat very rare, and their management is still debated due to the scarcity of information about their cell of origin, behavior, and biology. Treatment options are still limited, but we are confident that in the near future by discovering the genetic and biological mechanisms that drive tumor growth we will be able to offer new target therapies that should be flanked by surgery, radiotherapy, and chemotherapeutic agents actually in use. The purpose of this chapter is to highlight the most important known characteristics of these tumors offering the chance to recognize the disease and then offer the best opportunity for treatment to patients. The 5th WHO Classification Central Nervous System features substantial changes by moving further to advance the role of molecular diagnostics in CNS tumor classification, but remaining rooted in other established approaches to tumor characterization, including histology and immunohistochemistry, and probably, the category of many tumors will change. Here, the most important characteristics of each neoplasm are summarized focusing on genetic mechanisms and molecular pathways, their histopathologic footprints, signs and symptoms, radiologic features, therapeutic approaches, and prognosis as well as follow-up protocols. Schematic classifications are also presented to offer a better understanding of the pathology.

Immune signature of pheochromocytoma and paraganglioma in context of neuroendocrine neoplasms associated with prognosis

PURPOSE

To understand prognostic immune cell infiltration signatures in neuroendocrine neoplasms (NENs), particularly pheochromocytoma and paraganglioma (PCPG), we analyzed tumor transcriptomic data from The Cancer Genome Atlas (TCGA) and other published tumor transcriptomic data of NENs.

METHODS

We used CIBERSORT to infer immune cell infiltrations from bulk tumor transcriptomic data from PCPGs, in comparison to gastroenteropancreatic neuroendocrine tumors (GEPNETs) and small cell lung carcinomas (SCLCs). PCPG immune signature was validated with NanoString immune panel in an independent cohort. Unsupervised clustering of the immune infiltration scores from CIBERSORT was used to find immune clusters. A prognostic immune score model for PCPGs and the other NENs were calculated as a linear combination of the estimated infiltration of activated CD8+/CD4+ T cells, activated NK cells, and M0 and M2 macrophages.

RESULTS

In PCPGs, we found five dominant immune clusters, associated with M2 macrophages, monocytes, activated NK cells, M0 macrophages and regulatory T cells, and CD8+/CD4+ T cells respectively. Non-metastatic tumors were associated with activated NK cells and metastatic tumors were associated with M0 macrophages and regulatory T cells. In GEPNETs and SCLCs, M0 macrophages and regulatory T cells were associated with unfavorable outcomes and features, such as metastasis and high-grade tumors. The prognostic immune score model for PCPGs and the NENs could predict non-aggressive and non-metastatic diseases. In PCPGs, the immune score was also an independent predictor of metastasis-free survival in a multivariate Cox regression analysis.

CONCLUSION

The transcriptomic immune signature in PCPG correlates with clinical features like metastasis and prognosis.

Primary Functioning Hepatic Paraganglioma Treated by Laparoscopy: A Case Report

Paragangliomas are highly vascularised and often heritable tumors derived from the paraganglia. They are typically discovered in the retroperitoneal space as well as the head and neck region but are rarely encountered in the liver parenchyma. We report a case of a primary functioning hepatic paraganglioma and provide an up-to-date literature review of patients with such tumors. We present a case of functioning paraganglioma in a 34-year-old female patient who suffered a solitary lesion in her left lateral lobe with symptoms of hypertension since pregnancy. She did not have any family history and her pre-pregnancy examination was negative. An abdominal CT imaging revealed a 6.5 × 5.7 cm liver lesion in segments II and III. Laboratory investigations identified elevation in plasma-free catecholamines. With sufficient preoperative preparation, the patient underwent laparoscopic left hemihepatectomy. Immunohistochemical staining revealed Syn (+) tumor cell nests surrounded by S-100 sustentacular cells (+), providing a definitive diagnosis of paraganglioma. The patient recovered uneventfully without signs of recurrence during a 1-year follow-up period. Our case demonstrates that primary refractory hypertension in pregnancy should be screened for paraganglioma through abdominal ultrasound and plasma free catecholamines. On the other hand, laparoscopic surgery is technically safe and feasible for the treatment of patients with hepatic paragangliomas in favorable locations.

TNM Staging and Overall Survival in Patients with Pheochromocytoma and Sympathetic Paraganglioma

BACKGROUND

Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine tumors. Metastases develop in 15-20%. The American Joint Committee on Cancer (AJCC) established inaugural guidelines for PPGL tumor-node-metastasis (TNM) staging. The objective of this analysis is to investigate the associations between TNM staging and overall survival (OS).

METHODS

We retrospectively applied the TNM staging at the time of diagnosis of the primary tumor. The primary outcome was OS. Unadjusted survival rates were estimated by the Kaplan-Meier method. Cox proportional hazards regression models were used to evaluate the associations between OS and covariates of interest.

RESULTS

The study included 458 patients. Median OS was 18.0 (95% CI: 15.6-not reached) years. At diagnosis, 126 (27.5%) tumors were stage I, 213 (46.5%) were stage II, 47 (10.3%) were stage III, and 72 (15.7%) were stage IV. The 10-year OS probabilities were 0.844 (95% CI: 0.768-0.928) for patients with stage I tumors, 0.792 (95% CI: 0.726-0.865) for stage II, 0.595 (95% CI: 0.435-0.813) for stage III, and 0.221 (95% CI: 0.127-0.384) for stage IV. Compared with stage I, the hazard ratios (HR) for death were 1.50 (0.87-2.57) for stage II, 2.85 (1.45-5.63) for stage III, and 8.88 (5.16-15.29) for stage IV (p < 0.001). Compared with patients with no germline mutations, those with RET 634/918 had better OS (HR: 0.28, 95% CI: 0.12-0.69). Other germline mutations, including SDHB, did not exhibit worse OS than patients with metastasis and sporadic disease.

CONCLUSIONS

OS rates correlated with the recently developed AJCC TNM staging and was not worse in hereditary disease. Stage IV disease exhibited a significantly shorter OS compared with stages I-III. Future staging systems could be adjusted to better separate stages I and II.

Single-nuclei and bulk-tissue gene-expression analysis of pheochromocytoma and paraganglioma links disease subtypes with tumor microenvironment

Pheochromocytomas (PC) and paragangliomas (PG) are rare neuroendocrine tumors associated with autonomic nerves. Here we use single-nuclei RNA-seq and bulk-tissue gene-expression data to characterize the cellular composition of PCPG and normal adrenal tissues, refine tumor gene-expression subtypes and make clinical and genotypic associations. We confirm seven PCPG gene-expression subtypes with significant genotype and clinical associations. Tumors with mutations in VHL, SDH-encoding genes (SDHx) or MAML3-fusions are characterized by hypoxia-inducible factor signaling and neoangiogenesis. PCPG have few infiltrating lymphocytes but abundant macrophages. While neoplastic cells transcriptionally resemble mature chromaffin cells, early chromaffin and neuroblast markers are also features of some PCPG subtypes. The gene-expression profile of metastatic SDHx-related PCPG indicates these tumors have elevated cellular proliferation and a lower number of non-neoplastic Schwann-cell-like cells, while GPR139 is a potential theranostic target. Our findings therefore clarify the diverse transcriptional programs and cellular composition of PCPG and identify biomarkers of potential clinical significance.

Multimodality imaging appearance of intrapericardial paragangliomas

Paragangliomas are neuroendocrine tumours of the sympathetic and parasympathetic nervous systems originating from neural crest cells. Less than 1% of paragangliomas in the heart originate from intrinsic cardiac ganglia cells in the posterior wall of the atria, atrioventricular groove, and along the root of the great vessels. We describe the tumour characteristics, patient demographics, presentation, means of diagnosis, pathology correlation, management, and outcome in 11 patients with intrapericardial paragangliomas. To the authors' knowledge, this is the largest case series reported, with emphasis on multimodality imaging findings.

Unusually large paraganglioma complicated with successive catecholamine crises: A case report and review of the literature

Background

Paragangliomas are rare neuroendocrine tumors that could secret catecholamines. Hypertension and heart failure caused by the catecholamine crisis are fatal cardiovascular events. However, silent paragangliomas that lack typical symptoms of catecholamine pose a significant diagnostic challenge.

Case summary

A 45-year-old woman who presented with more than 1-year history of abdominal discomfort was suspected of having a gastrointestinal stromal tumor by a local hospital since a vast metastatic mass occupied her left abdomen. Thus, she was recommended to our hospital. After completing the gastroscopy, she unexpectedly developed acute heart failure and was transferred to the Intensive Care Unit (ICU) where the initial diagnosis of paraganglioma was considered through path. However, a second catecholamine crisis due to constipation led to acute heart failure again. After anti-heart failure therapy and rigorous preoperative preparation, surgery was arranged to remove the tumor. Postoperative pathology confirmed the paraganglioma, and the patient was discharged from the hospital in good condition.

Conclusion

We reported a rare case of huge retro-peritoneal paraganglioma with successive catecholamine crises and acute heart failure. This was probably the largest retro-peritoneal paraganglioma since the 1980s. Besides, we were the first to use surgical drawing to illustrate its complex anatomical adjacent relationship of retro-peritoneal paraganglioma. Our case emphasizes the inclusion of extra-adrenal paraganglioma in the differential diagnosis of retroperitoneal tumors. In suspected paragangliomas, catecholamine testing is preferable to invasive procedures including gastroscopy and biopsy to avoid triggering a catecholamine crisis. Surgical resection is the primary treatment. We highlight the priority of dealing with the venous reflux branches of the tumor to prevent the release of catecholamines into the blood. In particular, preoperative preparation plays a vital role in managing paraganglioma. Moreover, it is necessary to schedule genetic testing and clinical follow-up due to the metastatic potential of paragangliomas.

Pheochromocytoma manifesting as cortical blindness secondary to PRES with associated TMA: a case report and literature review

BACKGROUND

Pheochromocytomas are neoplasms originating from neuroectodermal chromaffin cells leading to excess catecholamine production. They are notorious for causing a triad of headaches, palpitations, and sweats. Though the Menard triad is one to be vigilant of, symptomatic presentation can vary immensely, hence the tumor earning the label "the great masquerader."

CASE PRESENTATION

We report a case of pheochromocytoma initially presenting with cortical blindness secondary to posterior reversible encephalopathy syndrome and thrombotic microangiopathy from malignant hypertension. Our patient was seen in our facility less than a week prior to this manifestation and discharged after an unremarkable coronary ischemia work-up. In the outpatient setting, she had been prescribed multiple anti-hypertensives with remarkably elevated blood pressure throughout her hospitalization history.

CONCLUSION

Pheochromocytoma presenting with malignant hypertension and hypertensive encephalopathy should be expected if left untreated; nonetheless, the precipitation of cortical blindness is rare in the literature. This case contributes an additional vignette to the growing literature revolving adrenal tumors and their symptomatic presentation along with complex management. It also serves to promote increased diagnostic suspicion among clinicians upon evaluating patients with refractory hypertension.

Clinical and Pathological Tools for Predicting Recurrence and/or Metastasis in Patients with Pheochromocytoma and Paraganglioma

Pheochromocytomas and paragangliomas are endocrine tumors belonging to the family of neural crest cell-derived neoplasms. They have an extremely variable clinical course, characterized by a non-negligible percentage of relapse and/or metastasis after radical surgery. To date, there are no reliable methods to predict the metastatic potential of these neoplasms, despite several clinical, molecular, and histopathological factors that have been extensively studied in the literature as predictors of the recurrence and/or metastasis in these neoplasms with different performances and results. In this review, we aimed to discuss and analyze the most important clinical and histopathological tools for predicting recurrence risk in patients affected by pheochromocytomas or paragangliomas. Thus, we compared the main available predictive models, exploring their applications in stratifying patients’ risks. In conclusion, we underlined the importance of simple and validated tools to better define disease aggressiveness and establish tailored patients’ treatments and follow-ups.

Novel GLCCI1-BRAF fusion drives kinase signaling in a case of pheochromocytomatosis

INTRODUCTION

Recurrent and metastatic pheochromocytoma (PCC) are rare advanced endocrine neoplasms with limited treatment options. Insight into the pathogenic molecular alterations in patients with advanced PCC can provide therapeutic options for precisely targeting dysregulated pathways.

OBJECTIVE

We report the discovery and characterization of a novel BRAF-containing fusion transcript and its downstream molecular alterations in a patient with recurrent PCC with peritoneal seeding (pheochromocytomatosis).

METHODS

We reviewed the medical record of a patient with pheochromocytomatosis. A comprehensive pan-cancer molecular profiling using next-generation sequencing (NGS) as well as confirmatory real-time-quantitative PCR were performed on surgical specimens. BRAF rearrangement and downstream molecular changes were assayed using fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC), respectively. Western blot was used to assess the in vitro activation of the mitogen-activated protein kinase (MAPK) signaling pathway and the EMT markers in transfected HEK-293 cells.

RESULTS

The NGS analysis of a specimen from a 72-year-old female patient with pheochromocytomatosis showed an in-frame fusion of exon 3 of Glucocorticoid Induced 1 (GLCCI1) to exon 9 of BRAF. The upstream auto-inhibitory domain of BRAF was excluded from the GLCCI1-BRAF fusion; however, the downstream BRAF kinase domain was intact. A BRAF rearrangement was confirmed via a BRAF-specific break-apart FISH assay. Four separate tumor foci harbored GLCCI1-BRAF fusion. IHC demonstrated increased phosphorylated MEK. HEK-293 cells transfected with the GLCCI1-BRAF fusion demonstrated increased phosphorylated MEK as well as higher expression of EMT markers SNAI1 and ZEB1 in vitro.

CONCLUSION

We demonstrate a novel pathogenic gene fusion of GLCCI1 with the oncogenic kinase domain of BRAF, resulting in an activation of the MAPK signaling pathway and EMT markers. Thus, this patient may benefit from clinically available MEK and/or BRAF inhibitors when systemic therapy is indicated.

SUMMARY STATEMENT

This report is the first of GLCCI1 fused to BRAF in a human neoplasm and only the second BRAF-containing fusion transcript in PCC. Detailed molecular characterization of PCC can be a valuable tool in managing patients with recurrent PCC and pheochromocytomatosis that represents a significant clinical challenge.

From SGAP-Model to SGAP-Score: A Simplified Predictive Tool for Post-Surgical Recurrence of Pheochromocytoma

A reliable prediction of the recurrence risk of pheochromocytoma after radical surgery would be a key element for the tailoring/personalization of post-surgical follow-up. Recently, our group developed a multivariable continuous model that quantifies this risk based on genetic, histopathological, and clinical data. The aim of the present study was to simplify this tool to a discrete score for easier clinical use. Data from our previous study were retrieved, which encompassed 177 radically operated pheochromocytoma patients; supervised regression and machine-learning techniques were used for score development. After Cox regression, the variables independently associated with recurrence were tumor size, positive genetic testing, age, and PASS. In order to derive a simpler scoring system, continuous variables were dichotomized, using > 50 mm for tumor size, ≤ 35 years for age, and ≥ 3 for PASS as cut-points. A novel prognostic score was created on an 8-point scale by assigning 1 point for tumor size > 50 mm, 3 points for positive genetic testing, 1 point for age ≤ 35 years, and 3 points for PASS ≥ 3; its predictive performance, as assessed using Somers’ D, was equal to 0.577 and was significantly higher than the performance of any of the four dichotomized predictors alone. In conclusion, this simple scoring system may be of value as an easy-to-use tool to stratify recurrence risk and tailor post-surgical follow-up in radically operated pheochromocytoma patients.

Integration of molecular imaging in the personalized approach of patients with adrenal masses

Adrenal masses are a frequent finding in clinical practice. Many of them are incidentally discovered with a prevalence of 4% in patients undergoing abdominal anatomic imaging and require a differential diagnosis. Biochemical tests, evaluating hormonal production of both adrenal cortex and medulla (in particular, mineralocorticoids, glucocorticoids and catecholamines), have a primary importance in distinguishing functional or non-functional lesions. Conventional imaging techniques, in particular computerized tomography (CT) and magnetic resonance imaging (MRI), are required to differentiate between benign and malignant lesions according to their appearance (size stability, contrast enhanced CT and/or chemical shift on MRI). In selected patients, functional imaging is a non-invasive tool able to explore the metabolic pathways involved thus providing additional diagnostic information. Several single photon emission tomography (SPET) and positron emission tomography (PET) radiopharmaceuticals have been developed and are available, each of them suitable for studying specific pathological conditions. In functional masses causing hypersecreting diseases (mainly adrenal hypercortisolism, primary hyperaldosteronism and pheochromocytoma), functional imaging can lateralize the involvement and guide the therapeutic strategy in both unilateral and bilateral lesions. In non-functioning adrenal masses with inconclusive imaging findings at CT/MR, [¹⁸F]-FDG evaluation of tumor metabolism can be helpful to characterize them by distinguishing between benign nodules and primary malignant adrenal disease (mainly adrenocortical carcinoma), thus modulating the surgical approach. In oncologic patients, [¹⁸F]-FDG uptake can differentiate between benign nodule and adrenal metastasis from extra-adrenal primary malignancies.

Aorto-iliac paraganglioma: Case report and literature review

Introduction

Paraganglioma and pheochromocytoma are uncommon conditions that affect around 1.5–9 patients per million. The most frequent symptoms are headache, hypertension and diaphoresis; however, palpitations or tachycardia could be present. Malignancy is not frequent, and when is suspected, positron emission tomography (PET) should be performed. Surgery it's the gold standard treatment, with acceptable rates of morbidity and mortality.

Presentation of the case

A 33-year-old woman presented to private practice with long-standing symptoms consisting of asthenia, adynamia, and sensation of palpable masses in the neck. Due to her medical history and imaging findings, urine metanephrines were obtained, showing high values of adrenaline 6.69 (μg/24 h), noradrenaline 130.09 (μg/24 h), dopamine 262.59 (μg/24 h). PET was performed to identify hyperfunctioning masses in other locations, finding bilateral carotid hypermetabolic masses and a nodular lesion anterior to the aortoiliac bifurcation, probably malignant. Laparoscopic retroperitoneal tumor resection was performed by a laparoscopic and metabolic surgeon, with intraoperative findings of a vascularized mass (30 × 25 mm) closely related to the left aortoiliac bifurcation and peritoneal fluid.

Discussion

Paragangliomas are rare tumors that frequently produce catecholamines with varied symptoms. Diagnosis requires patient history, laboratory studies including 24-hour urine-metanephrines and plasma metanephrine levels. Imaging such as CT, MRI and PET scan are necessary. Perioperative management needs to be performed and surgery is the basis of the treatment in patients with localized disease. Metastatic disease has a 50% mortality at 5 years and requires a different approach.

Conclusion

Paraganglioma is a rare and complex entity that requires a multidisciplinary approach.

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Paragangliomas are rare tumors that produce catecholamines with varied symptoms.

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Diagnosis requires a detailed history, laboratory and imaging studies.

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Perioperative management needs to be performed by a multidisciplinary board.

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Surgery is the cornerstone treatment of this pathology.

Metastatic pheochromocytomas and paragangliomas: where are we?

Pheochromocytomas and paragangliomas (PPGLs) can metastasize in approximately 15-20% of cases. This review discusses the available evidence on the biology and treatment of metastatic PPGLs. Chemotherapy is the first-line treatment option for this evolving and symptomatic disease. In patients with high MIBG uptake and positive PETGa-68, radiometabolic treatment may be considered. The efficacy of sunitinib has been shown in observational studies, and pembrolizumab has been evaluated in phase II clinical studies, while other agents investigated in this setting are anti-angiogenic drugs cabozantinib, dovitinib, axitinib and lenvatinib. As these agents' efficacy and safety data, alone or in combination, are scant and based on few treated patients, enrollment in clinical trials is mandatory. Future therapeutic options may be represented by DNA repair system inhibitors (such as olaparib), HIF2 inhibitors and immunotherapy.