Observer Variation in the Application of the Pheochromocytoma of the Adrenal Gland Scaled Score

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.

Validation and Evaluation of 5 Scoring Systems for Predicting Metastatic Risk in Pheochromocytoma and Paraganglioma

Currently, 5 scoring systems have been proposed in the literature for predicting metastatic risk in pheochromocytoma and paraganglioma (PPGL): Pheochromocytoma of the Adrenal Gland Scaled Score (PASS), Grading System for Adrenal Pheochromocytoma and Paraganglioma (GAPP), Composite Pheochromocytoma/paraganglioma Prognostic Score (COPPS), Age, Size, Extra-adrenal location, Secretion type (ASES) score, and Size, Genetic, Age, and PASS (SGAP) model. To validate and evaluate these 5 scoring systems, we conducted a retrospective review of cases diagnosed as PPGL at the Department of Pathology, West China Hospital of Sichuan University, between January 2012 and December 2019. A total of 185 PPGL cases were included, comprising 35 cases with metastasis and 150 cases remained metastasis-free for over 8 years after surgery. The criteria of the 5 scoring systems were used for scoring and risk classification. The predictive performance of the 5 scoring systems was validated, compared, and evaluated using concordance index (C-index) and decision curve analysis (DCA). The C-indices for PASS, GAPP, and SGAP were 0.600, 0.547, and 0.547, respectively, indicating low discriminative ability. In contrast, COPPS and ASES had C-indices of 0.740 and 0.706, respectively, indicating better discriminative performance. DCA also showed that the predictive capability of COPPS was superior to that of ASES, with both outperformed PASS, while PASS had better predictive ability than GAPP and SGAP. Our analysis indicated that pathology-based scoring systems cannot accurately predict metastatic risk of PPGL. Establishing a precise prediction system requires integrating clinical, pathologic, and molecular information, using a scientific methodology for predictive factor selection and weight assessment.

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.

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.

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.

Molecular classification and tumor microenvironment characteristics in pheochromocytomas

Pheochromocytomas (PCCs) are rare neuroendocrine tumors that originate from chromaffin cells in the adrenal gland. However, the cellular molecular characteristics and immune microenvironment of PCCs are incompletely understood. Here, we performed single-cell RNA sequencing (scRNA-seq) on 16 tissues from 4 sporadic unclassified PCC patients and 1 hereditary PCC patient with Von Hippel-Lindau (VHL) syndrome. We found that intra-tumoral heterogeneity was less extensive than the inter-individual heterogeneity of PCCs. Further, the unclassified PCC patients were divided into two types, metabolism-type (marked by NDUFA4L2 and COX4I2) and kinase-type (marked by RET and PNMT), validated by immunohistochemical staining. Trajectory analysis of tumor evolution revealed that metabolism-type PCC cells display phenotype of consistently active metabolism and increased metastasis potential, while kinase-type PCC cells showed decreased epinephrine synthesis and neuron-like phenotypes. Cell-cell communication analysis showed activation of the annexin pathway and a strong inflammation reaction in metabolism-type PCCs and activation of FGF signaling in the kinase-type PCC. Although multispectral immunofluorescence staining showed a lack of CD8+ T cell infiltration in both metabolism-type and kinase-type PCCs, only the kinase-type PCC exhibited downregulation of HLA-I molecules that possibly regulated by RET, suggesting the potential of combined therapy with kinase inhibitors and immunotherapy for kinase-type PCCs; in contrast, the application of immunotherapy to metabolism-type PCCs (with antigen presentation ability) is likely unsuitable. Our study presents a single-cell transcriptomics-based molecular classification and microenvironment characterization of PCCs, providing clues for potential therapeutic strategies to treat PCCs.

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.

[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.

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.

Lesion-based indicators predict long-term outcomes of pheochromocytoma and paraganglioma- SIZEPASS

Aim

We seek a simple and reliable tool to predict malignant behavior of pheochromocytoma and paraganglioma (PPGL).

Methods

This single-center prospective cohort study assessed size of primary PPGLs on preoperative cross-sectional imaging and prospectively scored specimens using the Pheochromocytoma of the Adrenal Gland Scaled Score (PASS). Multiplication of PASS points with maximum lesion diameter (in mm) yielded the SIZEPASS criterion. Local recurrence, metastasis or death from disease were surrogates defining malignancy.

Results

76 consecutive PPGL patients, whereof 58 with pheochromocytoma and 51 female, were diagnosed at a mean age of 52.0 ± 15.2 years. 11 lesions (14.5%) exhibited malignant features at a median follow-up (FU) of 49 months (range 4-172 mo). Median FU of the remaining cohort was 139 months (range 120-226 mo). SIZEPASS classified malignancy with an area under the curve (AUC) of 0.97 (95%CI 0.93-1.01; p<0.0001). Across PPGL, SIZEPASS >1000 outperformed all known predictors of malignancy, with sensitivity 91%, specificity 94%, and accuracy 93%, and an odds ratio of 72 fold (95%CI 9-571; P<0.001). It retained an accuracy >90% in cohorts defined by location (adrenal, extra-adrenal) or mutation status.

Conclusions

The SIZEPASS>1000 criterion is a lesion-based, clinically available, simple and effective tool to predict malignant behavior of PPGLs independently of age, sex, location or mutation status.

Genotype-Phenotype Correlations and Clinical Outcomes in 155 Cases of Pheochromocytoma and Paraganglioma

BACKGROUND

Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumours, often associated with germline mutations that influence the disease biology and clinical course. We aimed to describe the genotypic and phenotypic characteristics of a consecutive series of PPGL patients and correlate mutation status with clinical outcomes.

METHODS

We performed a retrospective cohort study of all PPGL patients who presented to a tertiary referral centre between March 2005 and February 2022. Genotypic, phenotypic and follow-up data were analysed.

RESULTS

A total of 140 patients were included. Of these, 94 (67%) patients underwent genetic testing and a mutation was detected in 36 (38%) patients. Mutation presence was associated with younger age, smaller tumour size and bilateral adrenal tumours. Disease recurrence occurred at a median time of 5.4 (IQR 2.8-11.0) years after treatment in 21 (15%) patients, of which 14 (67%) had a mutation in a susceptibility gene. Recurrence pattern was influenced by mutation type; higher local recurrence risk for SDHA, SDHB, and MEN2B disease, and higher metastatic risk for SDHB, VHL and MEN2A disease. Recurrence occurred in three (3%) patients with mutation absence. Multivariate analysis revealed that age  ≤40 years and mutation presence were associated with increased risk of disease recurrence.

CONCLUSIONS

Genotypic characteristics strongly influence disease presentation and recurrence risk, which may occur more than 5 years after initial treatment. Routine genetic testing of PPGL patients is warranted given the high prevalence of mutations, allowing for prognostication and tailored follow-up. In the presence of germline mutations, follow-up should be life-long.

Advances in Adrenal and Extra-adrenal Paraganglioma: Practical Synopsis for Pathologists

Adrenal paraganglioma (or "pheochromocytoma") and extra-adrenal paraganglioma, collectively abbreviated PPGL, are rare but spectacular nonepithelial neuroendocrine neoplasms. These are the most inheritable neoplasia of all, with a metastatic potential in a varying degree. As of such, these lesions demand careful histologic, immunohistochemical, and genetic characterization to provide the clinical team with a detailed report taking into account the anticipated prognosis and risk of syndromic/inherited disease. While no histologic algorithm, immunohistochemical biomarker, or molecular aberration single-handedly can identify potentially lethal cases upfront, the combined analysis of various risk parameters may stratify PPGL patients more stringently than previously. Moreover, the novel 2022 WHO Classification of Endocrine and Neuroendocrine Tumors also brings some new concepts into play, not least the reclassification of special neuroendocrine neoplasms (cauda equina neuroendocrine tumor and composite gangliocytoma/neuroma-neuroendocrine tumor) previously thought to belong to the spectrum of PPGL. This review focuses on updated key diagnostic and prognostic concepts that will aid when facing this rather enigmatic tumor entity in clinical practice.

Initial characterization of immune microenvironment in pheochromocytoma and paraganglioma

Due to fewer adverse events, faster onset of action, and longer durable responses compared to chemotherapy, immunotherapy has been widely used to treat advanced solid tumors. Moreover, immunotherapy can improve the autoimmune status, thus allowing patients to benefit from the treatment in the long term. The immune microenvironment status is closely associated with the response to chemotherapies. Here, we analyzed the characteristics of the immune microenvironment in pheochromocytoma and paraganglioma (PPGL). Immunohistochemistry showed that PD-L1 is sparely expressed in PPGL with low positive rates and low expression levels, an expression pattern, that is, not correlated with tumor malignancy. Moreover, the level of intratumoral CD4⁺ and CD8⁺ lymphocyte infiltration in PPGL is low, suggesting that the immune microenvironment in PPGL may be in "immune desertification" or "immune rejection" states in which CD4⁺ and CD8⁺ lymphocyte infiltration is prevented, rendering immunotherapy less effective. In sum, our results indicate that PPGL is a microsatellite-stable tumor with low tumor mutational burden (TMB) levels, weak neoantigen production, and poor tumor antigenicity, hinting at a poor response of PPGL to chemotherapies.

French AFU Cancer Committee Guidelines Update 2022-2024: Adrenal tumor - Assessment of an adrenal incidetaloma and oncological management

INTRODUCTION

The objective of this publication is to recall the initial work-up when faced with an adrenal incidentaloma and, if necessary, to establish the oncological management of an adrenal malignant tumor.

MATERIAL AND METHODS

The multidisciplinary working group updated French urological guidelines about oncological assessment of the adrenal incidentaloma, established by the CCAFU in 2020, based on an exhaustive literature review carried out on PubMed.

RESULTS

Although the majority of the adrenal masses are benign and non-functional, it is important to investigate them, as a percentage of these can cause serious endocrine diseases or be cancers. Malignant adrenal tumors are mainly represented by adrenocortical carcinomas (ACC), malignant pheochromocytomas (MPC) and adrenal metastases (AM). The malignancy assessment of an adrenal incident includes a complete history, a physical examination, a biochemical/hormonal assessment to look for subclinical hormonal secretion. Diagnostic hypotheses are sometimes available at this stage, but it is the morphological and functional imaging and the histological analysis, which will make it possible to close the malignancy assessment and make the oncological diagnosis.

CONCLUSIONS

ACC and MPC are mainly sporadic but a hereditary origin is always possible. ACC is suspected preoperatively but the diagnosis of certainty is histological. The diagnosis of MPC is more delicate and is based on clinic, biology and imagery. The diagnosis of certainty of AM requires a percutaneous biopsy. At the end, the files must be discussed within the COMETE - adrenal cancer network (Appendix 1).

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.

Colorectal paragangliomas with immunohistochemical deficiency of succinate dehydrogenase subunit B

Recent progress in paraganglioma (PGL) revealed genotype-phenotype relationship, especially succinate dehydrogenase complex subunit B (SDHB) gene mutation-related to the extra-adrenal origin and metastasis. SDHB-immunohistochemistry can detect all types of SDH-subunit mutations, and is a useful tool to detect SDH-mutation tumors. PGLs usually occur along with sympathetic, and parasympathetic chains, however, colorectal paraganglioma is extremely rare. We have experienced one sigmoid colon PGL and one rectal PGL. These colorectal PGLs: a sigmoid colon PGL measuring 25 mm associated with a gastrointestinal stromal tumor (GIST) of the stomach, and a rectal PGL measuring 75 × 45 mm with elevated norepinephrine level were analyzed by immunohistochemistry for INSM1, chromogranin A, synaptophysin, tyrosine hydroxylase, dopamine-beta-hydroxylase, and SDHB and SDHA. The tumors were strongly positive for above markers, however, negative for SDHB. Both PGLs negative for SDHB immunohistochemistry were defined SDHB-deficient PGLs. Histologic grading of the PGLs by GAPP was well differentiated in sigmoid PGL versus poorly differentiated in rectal PGL. Although these PGLs were the same Stage II of TNM classification, the patient with sigmoid colon PGL had neither recurrence nor metastasis for 5 years after the operation, however, the patient with rectal PGL suffered the recurrent multiple metastases and expired 5 years after the operation. Herein, we compared these colorectal PGLs in regard to the patients' prognostic factors. Patient prognosis with these colorectal PGLs was mostly related to the tumor size and histologic grade under the same situation of SDH-deficiency.

Overview of the 2022 WHO Classification of Paragangliomas and Pheochromocytomas

This review summarizes the classification of tumors of the adrenal medulla and extra-adrenal paraganglia as outlined in the 5th series of the WHO Classification of Endocrine and Neuroendocrine Tumors. The non-epithelial neuroendocrine neoplasms (NENs) known as paragangliomas produce predominantly catecholamines and secrete them into the bloodstream like hormones, and they represent a group of NENs that have exceptionally high genetic predisposition. This classification discusses the embryologic derivation of the cells that give rise to these lesions and the historical evolution of the terminology used to classify their tumors; paragangliomas can be sympathetic or parasympathetic and the term pheochromocytoma is used specifically for intra-adrenal paragangliomas that represent the classical sympathetic form. In addition to the general neuroendocrine cell biomarkers INSM1, synaptophysin, and chromogranins, these tumors are typically negative for keratins and instead have highly specific biomarkers, including the GATA3 transcription factor and enzymes involved in catecholamine biosynthesis: tyrosine hydroxylase that converts L-tyrosine to L-DOPA as the rate-limiting step in catecholamine biosynthesis, dopamine beta-hydroxylase that is present in cells expressing norepinephrine, and phenylethanolamine N-methyltransferase, which converts norepinephrine to epinephrine and therefore can be used to distinguish tumors that make epinephrine. In addition to these important tools that can be used to confirm the diagnosis of a paraganglioma, new tools are recommended to determine genetic predisposition syndromes; in addition to the identification of precursor lesions, molecular immunohistochemistry can serve to identify associations with SDHx, VHL, FH, MAX, and MEN1 mutations, as well as pseudohypoxia-related pathogenesis. Paragangliomas have a well-formed network of sustentacular cells that express SOX10 and S100, but this is not a distinctive feature, as other epithelial NENs also have sustentacular cells. Indeed, it is the presence of such cells and the association with ganglion cells that led to a misinterpretation of several unusual lesions as paragangliomas; in the 2022 WHO classification, the tumor formerly known as cauda equina paraganglioma is now classified as cauda equina neuroendocrine tumor and the lesion known as gangliocytic paraganglioma has been renamed composite gangliocytoma/neuroma and neuroendocrine tumor (CoGNET). Since the 4th edition of the WHO, paragangliomas have no longer been classified as benign and malignant, as any lesion can have metastatic potential and there are no clear-cut features that can predict metastatic behavior. Moreover, some tumors are lethal without metastatic spread, by nature of local invasion involving critical structures. Nevertheless, there are features that can be used to identify more aggressive lesions; the WHO does not endorse the various scoring systems that are reviewed but also does not discourage their use. The identification of metastases is also complex, particularly in patients with germline predisposition syndromes, since multiple lesions may represent multifocal primary tumors rather than metastatic spread; the identification of paragangliomas in unusual locations such as lung or liver is not diagnostic of metastasis, since these may be primary sites. The value of sustentacular cells and Ki67 labeling as prognostic features is also discussed in this new classification. A staging system for pheochromocytoma and extra-adrenal sympathetic PGLs, introduced in the 8th Edition AJCC Cancer Staging Manual, is now included. This paper also provides a summary of the criteria for the diagnosis of a composite paragangliomas and summarizes the classification of neuroblastic tumors. This review adopts a practical question-answer framework to provide members of the multidisciplinary endocrine oncology team with a most up-to-date approach to tumors of the adrenal medulla and extra-adrenal paraganglia.

Pheochromocytomas and Abdominal Paragangliomas: A Practical Guidance

Simple Summary

Pheochromocytomas and abdominal paragangliomas (PPGLs) are rare. They can be discovered incidentally by imaging with computed tomography or magnetic resonance imaging and during hormonal surveillance in patients with known genetic variants that are associated with PPGLs. As most PPGLs are functioning, a hormonal work-up evaluating for catecholamine excess is recommended. Classical symptoms, such as tachycardia, hypertension and headache, can be present, but when the PPGL is discovered as an incidentaloma, symptoms may be lacking or be more discrete. PPGLs carry malignant potential, and patients should undergo close surveillance, as recurrence of disease or metastasis may develop. Genetic susceptibility for multifocal disease has gained more attention, and germline variants are commonly detected, thus facilitating detection of hereditary cases and afflicted family members. Any patient with a PPGL should be managed by an expert multidisciplinary team consisting of endocrinologists, radiologists, surgeons, pathologists and clinical geneticists.

Abstract

Pheochromocytomas and abdominal paragangliomas (PPGLs) are rare tumors arising from the adrenal medulla or the sympathetic nervous system. This review presents a practical guidance for clinicians dealing with PPGLs. The incidence of PPGLs has risen. Most cases are detected via imaging and less present with symptoms of catecholamine excess. Most PPGLs secrete catecholamines, with diffuse symptoms. Diagnosis is made by imaging and tests of catecholamines. Localized disease can be cured by surgery. PPGLs are the most heritable of all human tumors, and germline variants are found in approximately 30–50% of cases. Such variants can give information regarding the risk of developing recurrence or metastases as well as the risk of developing other tumors and may identify relatives at risk for disease. All PPGLs harbor malignant potential, and current histological and immunohistochemical algorithms can aid in the identification of indolent vs. aggressive tumors. While most patients with metastatic PPGL have slowly progressive disease, a proportion of patients present with an aggressive course, highlighting the need for more effective therapies in these cases. We conclude that PPGLs are rare but increasing in incidence and management should be guided by a multidisciplinary team.

Retroperitoneal Paraganglioma With Asymptomatic Follicular Lymphoma: A Case Report

Paraganglioma (PGL) is a rare tumor originating from extra-adrenal paraganglionic chromaffin tissues, and most sympathetic PGLs have excessive catecholamine secretion. However, nonfunctional PGLs are sometimes found. Although malignant PGL is defined by metastasis to nonchromaffin tissues, it is difficult to predict malignancies due to the lack of reliable markers of potential malignancies. We report the case of a 69-year-old Japanese woman with an incidental retroperitoneal tumor and multiple enlarged mesenteric lymph nodes simultaneously. The patient had no subjective symptoms and there were no laboratory findings suggesting catecholamine hypersecretion. Both the retroperitoneal tumor and the enlarged mesenteric lymph nodes showed high accumulation of fluorodeoxyglucose (FDG), whereas metaiodobenzylguanidine (MIBG) was accumulated only at the retroperitoneal tumor. Although a retroperitoneal tumor was diagnosed as nonfunctional PGL by examination including MIBG scintigraphy, the cause of enlarged mesenteric lymph nodes could not be diagnosed by imaging and biochemical tests. As a result of retroperitoneal tumor resection and mesenteric lymph nodes sampling, histopathological examination revealed that a retroperitoneal tumor was PGL and enlarged mesenteric lymph nodes were follicular lymphoma. To reveal an underlying genetic factor, we performed whole exome sequencing of genomic DNA, and we identified 2 possible candidate variants in SDHD and DLST, but the pathogenicity of these variants remains uncertain in the present case. This rare case reinforces the importance of histopathological diagnosis of nonchromaffin tissue lesions in patients with PGL for the appropriate treatment strategy.

Potential Biomarkers of Metastasizing Paragangliomas and Pheochromocytomas

Paragangliomas and pheochromocytomas (PPGLs) are rare neuroendocrine tumors originating from paraganglionic tissue in many sites of the body. Most PPGLs are characterized by nonaggressive behavior but all of them have the potential to metastasize. PPGLs represent a great diagnostic dilemma as it is difficult to recognize tumors that are likely to be metastasizing; criteria of malignancy can be found both in benign and metastatic forms. This review aims to analyze the current knowledge of the nature of metastasizing PPGLs paying particular attention to head and neck paragangliomas (HNPGLs). Potential predictors of the malignancy risk for PPGLs were summarized and discussed. These data may also help in the development of diagnostic and prognostic strategies, as well as in the identification of novel potential therapeutic targets for patients with PPGLs.

Pheochromocytoma: A Clinicopathologic and Molecular Study of 390 Cases From a Single Center

Pheochromocytomas are rare neuroendocrine tumors arising from chromaffin cells in the adrenal medulla. They may occur sporadically or in the context of hereditary syndromes. All pheochromocytomas are considered to have malignant potential (defined as risk of metastasis, not local invasion). The use of grading systems with incorporated clinical and histopathologic parameters can help but not definitively predict the metastatic potential of pheochromocytomas. The recent discovery of susceptibility genes provided new insights into the pathogenesis and introduced additional approaches to estimate the metastatic risk of pheochromocytoma. However, the prevalence of these genetic signatures in pheochromocytomas has yet to be fully addressed. Therefore, in the present study, we retrospectively reviewed cases of pheochromocytoma from 1980 to 2018 in the archives of our institution. Three hundred ninety cases were identified, and their clinicopathologic characteristics and genetic statuses were analyzed. About 25% of the cases had metastases, which were more common in older patients (median, 49 y) than in younger ones. Univariate and multivariate analyses revealed that older age, Hispanic ethnicity, metastasis, and large primary tumor size were markedly associated with poor overall survival. In contrast, family history of pheochromocytoma, lack of symptoms, and bilateral adrenal involvement were associated with better survival. About 37% of the pheochromocytomas were associated with inherited syndromes. About 52% of tested patients had pathogenic mutations of pheochromocytoma susceptibility genes. Of these, succinate dehydrogenase B gene mutation had the strongest association with metastasis. These data support that genetic testing should be offered to all patients with pheochromocytoma.

Recurrence-Free Survival Analysis in Locally Advanced Pheochromocytoma: First Appraisal

CONTEXT

The behavior of locally advanced pheochromocytoma (LAP) remains unknown.

OBJECTIVE

We characterized the population with LAP and recurrence-free survival (RFS).

METHODS

This retrospective multicentric study was run within the ENDOCAN-COMETE network and French Group of Endocrine Tumors (GTE) from 2003 to 2018, including patients from 11 French referral centers with LAP as defined by capsular invasion, vascular invasion, adipose tissue invasion, and/or positive locoregional lymph nodes at diagnosis without evidence of distant metastasis. The main outcome measure was recurrence, defined as tumor reappearance, including local site and/or distant metastasis. The primary endpoint was RFS analysis; secondary endpoints were characterization, overall survival (OS), and prognostic factors of recurrence.

RESULTS

Among 950 patients, 90 (9%) exhibited LAP criteria and 55 met inclusion criteria (median age, 53 years; 61% males; 14% with germline mutation; 84% with catecholamine excess). LAP was defined by 31 (56%) capsular invasions, 27 (49%) fat invasions, 6 (11%) positive lymph nodes, and 22 (40%) vascular invasions. After median follow-up of 54 months (range, 6-180), 12 patients (22%) had recurrences and 3 (5%) died of metastatic disease. Median RFS was 115 months (range, 6-168). Recurrences were local in 2 patients, distant in 2, and both local and distant in 8 patients. Median OS of patients was not reached. Size above 6.5 cm (P = 0.019) and Ki-67 > 2% (P = 0.028) were identified as independent significant prognostic factors in multivariate analysis.

CONCLUSION

LAP represents 9% of pheochromocytoma's population and has a metastatic behavior. This study paves the way for future pathological TNM classification.

Malignant prediction in paragangliomas: analysis for clinical risk factors

INTRODUCTION

Paragangliomas are infrequent neuroendocrine tumours whose only criterion for malignancy is presence of metastases; thus, all paragangliomas show malignant potential. Actually, different risk factors have been analyzed to predict metastases but they remain unclear.

PURPOSE

To analyze clinical, histological, and genetic factors to predict the occurrence of metastasis.

PATIENTS AND METHOD

A multicentre retrospective observational analysis was performed between January 1990 and July 2019. Patients diagnosed with paraganglioma were selected. Clinical, histological, and genetic features were analyzed for the prediction of malignancy.

RESULTS

A total of 83 patients diagnosed with paraganglioma were included, of which nine (10.8%) had malignant paraganglioma. Tumour size was greater in malignant tumours than in benign (6 cm vs. 4 cm, respectively; p = 0.027). The most frequent location of malignancy was the thorax-abdomen-pelvis area observed in six cases (p = 0.024). No differences were observed in histological differentiation, age, symptoms, and catecholaminergic production. The most frequent genetic mutation was SDHD followed by SDHB but no differences were observed between benign and malignant tumours. In the univariate analysis for predictive factors for malignancy, location, tumour size, and histological differentiation showed statistical significance (p = 0.025, p = 0.014, and p = 0.046, respectively); however, they were not confirmed as predictive factors for malignancy in the multivariate analysis.

CONCLUSION

In this study, no risk factors for malignancy have been established; therefore, we recommend follow-up of all patients diagnosed with paraganglioma.

Challenges in Paragangliomas and Pheochromocytomas: from Histology to Molecular Immunohistochemistry

Abdominal paragangliomas and pheochromocytomas (PPGLs) are rare neuroendocrine tumors of the infradiaphragmatic paraganglia and adrenal medulla, respectively. Although few pathologists outside of endocrine tertiary centers will ever diagnose such a lesion, the tumors are well known through the medical community-possible due to a combination of the sheer rarity, their often-spectacular presentation due to excess catecholamine secretion as well as their unrivaled coupling to constitutional susceptibility gene mutations and hereditary syndromes. All PPGLs are thought to harbor malignant potential, and therefore pose several challenges to the practicing pathologist. Specifically, a responsible diagnostician should recognize both the capacity and limitations of histological, immunohistochemical, and molecular algorithms to pinpoint high risk for future metastatic disease. This focused review aims to provide the surgical pathologist with a condensed update regarding the current strategies available in order to deliver an accurate prognostication of these enigmatic lesions.

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Management of Metastatic and/or Unresectable Pheochromocytoma and Paraganglioma

ABSTRACT

This manuscript is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management and surveillance of metastatic and unresectable pheochromocytoma and paraganglioma held on October 2 and 3, 2019. The panelists consisted of endocrinologists, medical oncologists, surgeons, radiologists/nuclear medicine physicians, nephrologists, pathologists, and radiation oncologists. The panelists performed a literature review on a series of questions regarding the medical management of metastatic and unresectable pheochromocytoma and paraganglioma as well as questions regarding surveillance after resection. The panelists voted on controversial topics, and final recommendations were sent to all panel members for final approval.

Management and outcome of metastatic pheochromocytomas/paragangliomas: an overview

BACKGROUND

Metastatic pheochromocytomas and paragangliomas (PPGLs) occur in about 5-26% of cases and are characterized by a heterogeneous prognosis. Metastases can be synchronous at the initial diagnosis, but they can occur also many years after surgery for the primary tumor. To date, the treatment of patients affected by metastatic PPGLs represents a clinical challenge because of the lack of guidelines.

AIM

The aim of this article is to review the available management options and their impact on the outcomes of patients with metastatic PPGLs.

RESULTS

Generally, treatments are not curative. Surgery, when possible, can be used to reduce hormonal symptoms and cardiovascular morbidity. Chemotherapy plays a role in patients with high burden tumor and rapid disease progression. Tyrosine kinases inhibitors (TKIs) might be considered for their ability to block the angiogenesis and cell growth. Radiation therapy and interventional radiology techniques can help in the management of local metastases to control symptoms and avoid tumor progression. On the other hand, peptide receptor radionuclide therapy (PRRT), using ⁹⁰Y or ¹⁷⁷Lu-DOTATATE, could be a promising therapy. In addition, high specific ¹³¹I-MIBG was approved by the Food and Drug Administration (FDA) in the US for the treatment of patients affected by metastatic and unresectable ¹³¹I-MIBG positive PPGLs. Considering the different pathways involved in the pathogenesis of PPGLs, several target therapies have been proposed and are under evaluation in clinical trials.

CONCLUSIONS

The choice of the appropriate treatment should be based on multidisciplinary and personalized approach taking into account the rarity and the variability of these tumors.

[French ccAFU guidelines - update 2020-2022: malignancy assessment of an adrenal incidentaloma]

INTRODUCTION

- The objective of this publication is to recall the initial oncological management of adrenal incidentalomas.

MATERIAL & METHODS

- The multidisciplinary working group updated french urological guidelines established by the CCAFU in 2018, based on an exhaustive literature review carried out on PubMed.

RESULTS

- Although the majority of the adrenal masses are benign and non-functional, it is important to investigate them, as a percentage of these can cause serious endocrine diseases or be cancers. Malignant adrenal tumors are mainly represented by Adrenocortical Carcinomas (ACC), malignant pheochromocytomas (MPC) and adrenal metastases (AM). The malignancy assessment of an adrenal incident includes a complete history, a physical examination, a biochemical / hormonal assessment to look for subclinical hormonal secretion. Diagnostic hypotheses are sometimes available at this stage, but it is the morphological and functional imaging and the histological analysis which will make it possible to close the malignancy assessment and make the oncological diagnosis.

CONCLUSIONS

- AC and MPC are mainly sporadic but a hereditary origin is always possible. ACC is suspected preoperatively but the diagnosis of certainty is histological. The diagnosis of MPC is more delicate and is based on clinic, biology and imagery. The diagnosis of certainty of AM requires a percutaneous biopsy. At the end, the files must be discussed within the COMETE - adrenal cancer network (Appendix 1).

Adrenal Incidentaloma

An adrenal incidentaloma is now established as a common endocrine diagnosis that requires a multidisciplinary approach for effective management. The majority of patients can be reassured and discharged, but a personalized approach based upon image analysis, endocrine workup, and clinical symptoms and signs are required in every case. Adrenocortical carcinoma remains a real concern but is restricted to <2% of all cases. Functional adrenal incidentaloma lesions are commoner (but still probably <10% of total) and the greatest challenge remains the diagnosis and optimum management of autonomous cortisol secretion. Modern-day surgery has improved outcomes and novel radiological and urinary biomarkers will improve early detection and patient stratification in future years to come.

Predicting Metastatic Potential in Pheochromocytoma and Paraganglioma: A Comparison of PASS and GAPP Scoring Systems

PURPOSE

The Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) and the Grading System for Adrenal Pheochromocytoma and Paraganglioma (GAPP) are scoring systems to predict metastatic potential in pheochromocytomas (PCC) and paragangliomas (PGLs). The goal of this study is to assess PASS and GAPP as metastatic predictors and to correlate with survival outcomes.

METHODS

The cohort included PCC/PGL with ≥5 years of follow-up or known metastases. Surgical pathology slides were rereviewed. PASS and GAPP scores were assigned. Univariable and multivariable logistic regression, Kaplan-Meier survival analysis, and Cox proportional hazards were performed to assess recurrence-free survival (RFS) and disease-specific survival (DSS).

RESULTS

From 143 subjects, 106 tumors were PCC and 37 were PGL. Metastases developed in 24%. The median PASS score was 6.5 (interquartile range [IQR]: 4.0-8.0) and median GAPP score was 3.0 (IQR: 2.0-4.0). Interrater reliability was low-moderate for PASS (intraclass correlation coefficient [ICC]: 0.6082) and good for GAPP (ICC 0.7921). Older age (OR: 0.969, P = .0170) was associated with longer RFS. SDHB germline pathogenic variant (OR: 8.205, P = .0049), extra-adrenal tumor (OR: 6.357, P < .0001), Ki-67 index 1% to 3% (OR: 4.810, P = .0477), and higher GAPP score (OR: 1.537, P = .0047) were associated with shorter RFS. PASS score was not associated with RFS (P = .1779). On Cox regression, a GAPP score in the moderately differentiated range was significantly associated with disease recurrence (HR: 3.367, P = .0184) compared with well-differentiated score.

CONCLUSION

Higher GAPP scores were associated with aggressive PCC/PGL. PASS score was not associated with metastases and demonstrated significant interobserver variability. Scoring systems for predicting metastatic PCC/PGL may be improved by incorporation of histopathology, clinical data, and germline and somatic tumor markers.

Long-term outcomes of abdominal paraganglioma

Purpose

Paragangliomas (PGL) are rare neuroendocrine tumors derived from chromaffin cells of the autonomic nervous system. We aim to describe our experience and the long-term outcome of abdominal PGL over the last decade.

Methods

A retrospective review of patients diagnosed with PGL in our hospital between November 2005 and June 2017 was conducted. All nonabdominal PGL were excluded and the clinicopathological features and long-term outcomes of the patients were analyzed.

Results

A total of 46 patients were diagnosed with abdominal PGL. The average age of diagnosis was 55.4 years and there was no sex predilection. The average tumor size was 5.85 cm and they were predominantly located in the infrarenal position (50%). The mean follow-up period was 42 months (range, 1.8–252 months). All patients with metastases had Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) of ≥4. One patient presented with synchronous metastases while 2 developed local recurrence and distant metastases. One presented with only local recurrence. One patient died 5 years after diagnosis.

Conclusion

Abdominal PGL is a rare tumor with excellent long-term prognosis. Recurrence although uncommon, can occur decades after initial diagnosis. Long-term follow-up is therefore recommended for all patients with PGL, especially in patients with PASS of ≥4.

Malignant pheochromocytoma and paraganglioma: management options

PURPOSE OF REVIEW

Although the majority of pheochromocytoma and paraganglioma are benign, 15-17% develop metastatic disease, being present at the initial diagnosis in about 11-31% of cases. The natural course of metastasized disease is highly heterogeneous, with an overall 5-year survival rate varying between 40% and 85%. For individual patients, overall survival, progression-free survival, and clinical outcome are difficult to predict. Management of metastasized pheochromocytoma and paraganglioma is challenging. Currently available therapeutic options are surgical debulking, treatment with radiopharmaceuticals (I-MIBG, Y and Lu-DOTATATE), chemotherapy and targeted therapy.

RECENT FINDINGS

The pathogenesis of pheochromocytoma and paraganglioma (PPGL) is largely driven by genomic alterations in PPGL susceptibility genes related to three different clusters: altered pseudo-hypoxic signaling (cluster-1), altered MAP-kinase signaling (cluster-2) and altered Wnt signaling (cluster-3). Novel targeted therapies (tyrosine kinase inhibitors) and potential future therapeutic options, guided by improved knowledge about the oncogenic cluster 1-3 signaling pathways, will be discussed.

SUMMARY

Treatment of metastasized pheochromocytoma and paraganglioma remains challenging. Profiling of gene expression and methylation can serve as a powerful tool for characterizing disease clusters and for guiding targeted therapy to improve selectivity and efficacy. Current knowledge of signatures involved in molecular signaling, metabolism, and resistance mechanisms of PPGLs suggests that therapeutic regimens can be optimized to each molecular subtype.

Genotype-phenotype associations in PPGLs in 59 patients with variants in SDHX genes

Phaeochromocytomas and paragangliomas (PPGLs) are tumours of the adrenal medulla and extra-adrenal sympathetic nervous system which often secrete catecholamines. Variants of the SDHX (SDHA, -AF2, -B, -C, -D) genes are a frequent cause of familial PPGLs. In this study from a single tertiary centre, we aimed to characterise the genotype-phenotype associations in patients diagnosed with germline variants in SDHX genes. We also assessed whether systematic screening of family members resulted in earlier detection of tumours. The study cohort comprised all individuals (n = 59) diagnosed with a rare variant in SDHX during a 13-year period. Patient- and pathology records were checked for clinical characteristics and histopathological findings. We found distinct differences in the clinical and histopathological characteristics between genetic variants in SDHB. We identified two SDHB variants with distinct phenotypical patterns. Family screening for SDHB variants resulted in earlier detection of tumours in two families. Patients with SDHA, SDHC and SDHD variants also had malignant phenotypes, underlining the necessity for a broad genetic screening of the proband. Our study corroborates previous findings of poor prognostic markers and found that the genetic variants and clinical phenotype are linked and, therefore, useful in the decision of clinical follow-up. Regular tumour screening of carriers of pathogenic variants may lead to an earlier diagnosis and expected better prognosis. The development of a combined algorithm with clinical, genetic, morphological, and biochemical factors may be the future for improved clinical risk stratification, forming a basis for larger multi-centre follow up studies.

Data set for the reporting of pheochromocytoma and paraganglioma: explanations and recommendations of the guidelines from the International Collaboration on Cancer Reporting

BACKGROUND AND OBJECTIVES

The International Collaboration on Cancer Reporting (ICCR) is a not-for-profit to develop evidence-based, internationally agreed-upon standardized data sets for each anatomic site, to be used throughout the world. Providing global standardization of pathology tumor classification, staging, and other reporting elements will lead to improved patient management and enhanced epidemiological research.

METHODS

Pheochromocytoma and paraganglioma are uncommon and are frequently overlooked in registry data sets. Malignant criteria have previously been defined only when there was metastatic disease.

RESULTS

With recent recognition of a significant inheritance association and the development of risk stratification tools, this data set was created in order to obtain more meaningful outcomes and management data, using similar criteria across the global pathology community. Issues related to key core and non-core elements, especially clinical hormonal status, familial history, tumor focality, proliferative fraction, adverse or risk stratification features, and ancillary techniques, are discussed in the context of daily application to these types of specimens.

CONCLUSIONS

The ICCR data set, developed by an international panel of endocrine organ specialists, establishes a pathology-standardized reporting guide for pheochromocytoma and paraganglioma.

Disease monitoring of patients with pheochromocytoma or paraganglioma by biomarkers and imaging studies

Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors, a large proportion of which secrete catecholamines. PPGL are associated with a high cardiovascular morbidity and come with a risk of malignancy. The therapy of choice is surgical resection. Nevertheless, PPGL are associated with a lifelong risk of tumor persistence or recurrence. Currently, there are no clinical, biochemical, histopathological or imaging characteristics, which can predict or exclude malignant behavior or tumor recurrence. Therefore, long-term follow-up is recommended even after apparent complete surgical removal. Early detection of recurrence is essential to reduce cardiovascular morbidity and mortality due to catecholamine secretion, to prevent morbidity by mass effects of paraganglioma (PGL) or by metastatic spread of disease. Due to the rarity of these tumors, no prospective data on long-term surveillance exist. In fact, current recommendations are based on retrospective analyses, expert opinions and case studies. The aim of this review is to provide an overview on the current state of knowledge with regard to known factors that increase the risk of recurrence and might impact disease monitoring as well as the available possibilities for biochemical and imaging follow-up. Based on this overview, we aim to propose a practical approach for a patient-oriented follow-up after surgical removal of a PPGL.

Metastatic pheochromocytoma and paraganglioma: Management of endocrine manifestations, surgery and ablative procedures, and systemic therapies

Metastatic pheochromocytomas and paragangliomas (MPPGs) are rare neuroendocrine tumors. Most patients present with advanced disease that is associated with manifestations of catecholamine release. Surgical resection of the primary tumor and ablative therapies of metastases-whenever possible-may improve clinical outcomes and, perhaps, lengthen the patient's overall survival. Significant steps in understanding the genetic alterations linked to MPPGs and scientific progress made on cancers that share a similar pathogenesis are leading to the recognition of potential systemic therapeutic options. Data derived from clinical trials evaluating targeted therapies such as tyrosine kinase inhibitors, radiopharmaceuticals, immunotherapy, and combinations of these will likely improve the outcomes of patients with advanced and progressive MPPGs. Exemplary of this success is the recent approval in the United States of the high-specific-activity iodine¹³¹ meta-iodine-benzylguanidine (MIBG) for patients with unresectable and progressive MPPGs that express the noradrenaline transporter. This review will discuss the therapeutic approaches for patients with MPPGs.

Update on Pheochromocytoma and Paraganglioma from the SSO Endocrine and Head and Neck Disease Site Working Group, Part 2 of 2: Perioperative Management and Outcomes of Pheochromocytoma and Paraganglioma

This is the second part of a two-part review on pheochromocytoma and paragangliomas (PPGLs). In this part, perioperative management, including preoperative preparation, intraoperative, and postoperative interventions are reviewed. Current data on outcomes following resection are presented, including outcomes after cortical-sparing adrenalectomy for bilateral adrenal disease. In addition, pathological features of malignancy, surveillance considerations, and the management of advanced disease are also discussed.

Molecular Profiling of Pheochromocytoma and Abdominal Paraganglioma Stratified by the PASS Algorithm Reveals Chromogranin B as Associated With Histologic Prediction of Malignant Behavior

Pheochromocytomas (PCCs) and abdominal paragangliomas (PGLs), collectively abbreviated PPGL, are believed to exhibit malignant potential-but only subsets of cases will display full-blown malignant properties. The Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) algorithm is a proposed histologic system to detect potential for aggressive behavior, but little is known regarding the coupling to underlying molecular genetics. In this study, a total of 92 PPGLs, previously characterized for susceptibility gene status and mRNA expressional profiles, were histologically assessed using the PASS criteria. A total of 32/92 PPGLs (35%) exhibited a PASS score ≥4, including all 8 cases with malignant behavior (7 with known metastases and 1 with extensively infiltrative local recurrence). Statistical analyzes between expressional data and clinical parameters as well as individual PASS criteria yielded significant associations to Chromogranin B (CHGB), BRCA2, HIST1H3B, BUB1B, and RET to name a few, and CHGB had the strongest correlation to both PASS and metastasis/local recurrence of all analyzed genes. Evident CHGB downregulation was observed in PPGLs with high PASS and overtly malignant behavior, and was also associated with shorter disease-related survival. This finding was validated using quantitative real-time polymerase chain reaction, in which CHGB expression correlated with both PASS and metastasis/local recurrence with consistent findings obtained in the TCGA cohort. Moreover, immunohistochemical analyses of subsets of tumors showed a correlation between high PASS scores and negative or weak CHGB protein expression. Patients with PPGLs obtaining high PASS scores postoperatively, also exhibited low preoperative plasma levels of CHGB. These data collectively point out CHGB as a possible preoperative and postoperative marker for PPGLs with potential for aggressive behavior.

Recent Advances in Histopathological and Molecular Diagnosis in Pheochromocytoma and Paraganglioma: Challenges for Predicting Metastasis in Individual Patients

Pheochromocytomas and paragangliomas (PHEO/PGL) are rare but occasionally life-threatening neoplasms, and are potentially malignant according to WHO classification in 2017. However, it is also well known that histopathological risk stratification to predict clinical outcome has not yet been established. The first histopathological diagnostic algorithm for PHEO, "PASS", was proposed in 2002 by Thompson et al. Another algorithm, GAPP, was then proposed by Kimura et al. in 2014. However, neither algorithm has necessarily been regarded a 'gold standard' for predicting post-operative clinical behavior of tumors. This is because the histopathological features of PHEO/PGL are rather diverse and independent of their hormonal activities, as well as the clinical course of patients. On the other hand, recent developments in wide-scale genetic analysis using next-generation sequencing have revealed the molecular characteristics of pheochromocytomas and paragangliomas. More than 30%-40% of PHEO/PGL are reported to be associated with hereditary genetic abnormalities involving > 20 genes, including SDHXs, RET, VHL, NF1, TMEM127, MAX, and others. Such genetic alterations are mainly involved in the pathogenesis of pseudohypoxia, Wnt, and kinase signaling, and other intracellular signaling cascades. In addition, recurrent somatic mutations are frequently detected and overlapped with the presence of genetic alterations associated with hereditary diseases. In addition, therapeutic strategies specifically targeting such genetic abnormalities have been proposed, but they are not clinically applicable at this time. Therefore, we herein review recent advances in relevant studies, including histopathological and molecular analyses, to summarize the current status of potential prognostic factors in patients with PHEO/PGL.

Histopathological Analysis of Tumor Microenvironment and Angiogenesis in Pheochromocytoma

Pheochromocytomas (PHEOs) are relatively rare catecholamine-producing tumors derived from adrenal medulla. Tumor microenvironment (TME) including neoangiogenesis has been explored in many human neoplasms but not necessarily in PHEOs. Therefore, in this study, we examined tumor infiltrating lymphocytes (CD4 and CD8), tumor associated macrophages (CD68 and CD163), sustentacular cells (S100p), and angiogenic markers (CD31 and areas of intratumoral hemorrhage) in 39 cases of PHEOs in the quantitative fashion. We then compared the results with pheochromocytoma of the adrenal gland scaled score (PASS), grading system for pheochromocytoma and paraganglioma (GAPP) and the status of intra-tumoral catecholamine-synthesizing enzymes (TH, DDC, and PNMT) as well as their clinicopathological factors. Intratumoral CD8 (p = 0.0256), CD31 (p = 0.0400), and PNMT (p = 0.0498) status was significantly higher in PHEOs with PASS <4 than PASS ≧4. In addition, intratumoral CD8⁺ lymphocytes were also significantly more abundant in well-than moderately differentiated PHEO according to GAPP score (p = 0.0108) and inversely correlated with tumor size (p = 0.0257). Intratumoral CD68⁺ cells were significantly higher in PHEOs with regular or normal histological patterns than those not (p = 0.0370) and inversely correlated with tumor size (p = 0.0457). The status of CD163 was significantly positively correlated with that of CD8 positive cells (p = 0.0032). The proportion of intratumoral hemorrhage areas was significantly higher in PHEOs with PASS ≧4 (p = 0.0172). DDC immunoreactivity in tumor cells was significantly positively correlated with PASS score (p = 0.0356) and TH status was significantly higher in PHEOs harboring normal histological patterns (p = 0.0236) and cellular monotony (p = 0.0219) than those not. Results of our present study did demonstrate that abundant CD8⁺ and CD68⁺ cells could represent a histologically low-scored tumor. In particular, PHEOs with increased intratumoral hemorrhage should be considered rather malignant. In addition, abnormal catecholamine-producing status of tumor cells such as deficient PNMT and TH and increased DDC could also represent more aggressive PHEOs.

[French ccAFU guidelines - Update 2018-2020: Adrenal cancer]

OBJECTIVE

To update French oncology guidelines concerning adrenal cancer.

METHODS

Comprehensive Medline search between 2016 and 2018 upon diagnosis, treatment and follow-up of adrenal cancer to update 2013 guidelines. Level of evidence was evaluated according to AGREE-II.

RESULTS

Adrenal cancers are mainly represented by adrenocortical carcinomas (AC), malignant pheochromocytomas (MPC) and adrenal metastases (AM). Medical background of these tumors is either the exploration of hormonal or tumor symptoms, or an adrenal incidentaloma. Etiological explorations are based on hormonal biochemical assessment, morphological and functional imaging and histological analysis. AC and MPC are mostly sporadic but hereditary origin is still possible. The suspicion of AC is driven mainly by radiological signs of malignancy, signs of local invasion or distant metastasis, and type of hormonal secretion but the accurate diagnosis is histological. The diagnosis of MPC is clinical, biological and radiological. The diagnosis of MS involves a percutaneous biopsy. Medical files for primitive adrenal cancer should be discussed within the COMETE - Adrenal Cancer Network (Appendix 1). Oncological adjuvant treatments are specific for the histological type. In the AC, their indication depends on the risk of recurrence and is based on mitotane, external radiotherapy or chemotherapy. In the MPC, it is based on internal radiotherapy and chemotherapy. Metastatic forms treatment is exceptionally surgical. Debulking is uncommon. For metastatic unresectable AC, treatment is based on mitotane monotherapy or triple chemotherapy. For metastatic unresectable MPC, treatment is based on exclusive metabolic radiotherapy or triple chemotherapy. Recurrences are frequent and sometimes delayed, which justifies a close and long follow-up.

CONCLUSION

The curative treatment of Adrenal cancers is surgical provided. This treatment is rarely sufficient alone, the prognosis is then pejorative.

Predictors of recurrence of pheochromocytoma and paraganglioma: a multicenter study in Piedmont, Italy

The available data on the natural history of pheochromocytomas and paragangliomas after radical surgery are heterogeneous and discordant. The aim of our retrospective multicenter study was to find predictors of recurrence in patients with pheochromocytomas and sympathetic paragangliomas submitted to radical surgery in Piedmont (a region in northwest Italy). We collected data from 242 patients diagnosed between 1990 and 2016. Forty-two patients (17.4%) had disease recurrence. Multivariate analysis showed that genetic mutation (HR = 3.62; 95% CI 1.44-9.13; p = 0.006), younger age (HR = 0.97; 95% CI 0.95-0.99; p = 0.031) and larger tumor size (HR = 1.01; 95% CI 1.00-1.02; p = 0.015) were independently associated with a higher recurrence risk of pheochromocytoma and paraganglioma; in pheochromocytomas, genetic mutation (HR = 3.4; 95% CI 1.00-11.48; p = 0.049), younger age (HR = 0.97; 95% CI 0.94-0.99; p = 0.02), higher tumor size (HR = 1.01; 95% CI 1.00-1.03; p = 0.043) and PASS value (HR = 1.16; 95% CI 1.03-1.3; p = 0.011) were associated with recurrence. Moreover, tumor size was the only predictor of metastatic pheochromocytoma and paraganglioma (HR = 4.6; 95% CI 1.4-15.0; p = 0.012); tumor size (HR = 3.93; 95% CI 1.2-16.4; p = 0.026) and PASS value (HR = 1.27; 95% CI 1.06-1.53; p = 0.007) were predictors of metastatic pheochromocytoma. In conclusion, our findings suggest that the recurrence of pheochromocytoma and sympathetic paraganglioma develops more frequently in younger subjects, patients with a family history of chromaffin tissue neoplasms, mutations in susceptibility genes, larger tumors and higher values of PASS. We recommend genetic testing in all patients with PPGL and strict follow-up at least on an annual basis.

Intricacies of the Molecular Machinery of Catecholamine Biosynthesis and Secretion by Chromaffin Cells of the Normal Adrenal Medulla and in Pheochromocytoma and Paraganglioma

The adrenal medulla is composed predominantly of chromaffin cells producing and secreting the catecholamines dopamine, norepinephrine, and epinephrine. Catecholamine biosynthesis and secretion is a complex and tightly controlled physiologic process. The pathways involved have been extensively studied, and various elements of the underlying molecular machinery have been identified. In this review, we provide a detailed description of the route from stimulus to secretion of catecholamines by the normal adrenal chromaffin cell compared to chromaffin tumor cells in pheochromocytomas. Pheochromocytomas are adrenomedullary tumors that are characterized by uncontrolled synthesis and secretion of catecholamines. This uncontrolled secretion can be partly explained by perturbations of the molecular catecholamine secretory machinery in pheochromocytoma cells. Chromaffin cell tumors also include sympathetic paragangliomas originating in sympathetic ganglia. Pheochromocytomas and paragangliomas are usually locally confined tumors, but about 15% do metastasize to distant locations. Histopathological examination currently poorly predicts future biologic behavior, thus long term postoperative follow-up is required. Therefore, there is an unmet need for prognostic biomarkers. Clearer understanding of the cellular mechanisms involved in the secretory characteristics of pheochromocytomas and sympathetic paragangliomas may offer one approach for the discovery of novel prognostic biomarkers for improved therapeutic targeting and monitoring of treatment or disease progression.

Pheochromocytomas and Paragangliomas: New Developments with Regard to Classification, Genetics, and Cell of Origin

Pheochromocytomas (PCC) and paragangliomas (PGL) are rare neuroendocrine tumors that arise in the adrenal medulla and in extra-adrenal locations, such as the head, neck, thorax, abdomen, and pelvis. Classification of these tumors into those with or without metastatic potential on the basis of gross or microscopic features is challenging. Recent insights and scoring systems have attempted to develop solutions for this, as described in the latest World Health Organization (WHO) edition on endocrine tumor pathology. PCC and PGL are amongst the tumors most frequently accompanied by germline mutations. More than 20 genes are responsible for a hereditary background in up to 40% of these tumors; somatic mutations in the same and several additional genes form the basis for another 30%. However, this does not allow for a complete understanding of the pathogenesis or targeted treatment of PCC and PGL, for which surgery is the primary treatment and for which metastasis is associated with poor outcome. This review describes recent insights into the cell of origin of these tumors, the latest developments with regard to the genetic background, and the current status of tumor classification including proposed scoring systems.

Targeted Radionuclide Therapy for Patients with Metastatic Pheochromocytoma and Paraganglioma: From Low-Specific-Activity to High-Specific-Activity Iodine-131 Metaiodobenzylguanidine

Low-specific-activity iodine-131–radiolabeled metaiodobenzylguanidine (I-131-MIBG) was introduced last century as a potential systemic therapy for patients with malignant pheochromocytomas and paragangliomas. Collective information derived from mainly retrospective studies has suggested that 30–40% of patients with these tumors benefit from this treatment. A low index of radioactivity, lack of therapeutic standardization, and toxicity associated with intermediate to high activities (absorbed radiation doses) has prevented the implementation of I-131-MIBG’s in clinical practice. High-specific-activity, carrier-free I-131-MIBG has been developed over the past two decades as a novel therapy for patients with metastatic pheochromocytomas and paragangliomas that express the norepinephrine transporter. This drug allows for a high level of radioactivity, and as yet is not associated with cardiovascular toxicity. In a pivotal phase two clinical trial, more than 90% of patients achieved partial responses and disease stabilization with the improvement of hypertension. Furthermore, many patients exhibited long-term persistent antineoplastic effects. Currently, the high-specific-activity I-131-MIBG is the only approved therapy in the US for patients with metastatic pheochromocytomas and paragangliomas. This review will discuss the historical development of high-specific-activity I-131-MIBG, its benefits and adverse events, and future directions for clinical practice applicability and trial development.

[Tumors of the adrenal glands : Update]

Nodular hyperplasias and adenomas are by far the most frequently resected tumors of the adrenal cortex followed by pheochromocytomas, which are either discovered incidentally or become conspicuous due to hormonal hypersecretions. Cortical nodes and adenomas are easy to diagnose using simple staining methods. Uncertain cortical carcinomas, pheochromocytomas and other tumors of the adrenal region require additional immunohistochemical staining methods. Determination of the dignity of tumors of the adrenal cortex necessitates at least the Weiss score (possibly in its modified form), for oncocytic tumors the Bisceglia score and for pediatric tumors the Wieneke score. The Ki-67 index must also be taken into consideration. For pheochromocytomas the PASS and the GAPP systeme are used.

The Value of Histological Algorithms to Predict the Malignancy Potential of Pheochromocytomas and Abdominal Paragangliomas-A Meta-Analysis and Systematic Review of the Literature

Pheochromocytomas (PCCs) and abdominal paragangliomas (PGLs), collectively abbreviated PPGLs, are neuroendocrine tumors of the adrenal medulla and paraganglia, respectively. These tumors exhibit malignant potential but seldom display evidence of metastatic spread, the latter being the only widely accepted evidence of malignancy. To counter this, pre-defined histological algorithms have been suggested to stratify the risk of malignancy: Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) and the Grading system for Adrenal Pheochromocytoma and Paraganglioma (GAPP). The PASS algorithm was originally intended for PCCs whereas the GAPP model is proposed for stratification of both PCCs and PGLs. In parallel, advances in terms of coupling overtly malignant PPGLs to the underlying molecular genetics have been made, but there is yet no combined risk stratification model based on histology and the overall mutational profile of the tumor. In this review, we systematically meta-analyzed previously reported cohorts using the PASS and GAPP algorithms and acknowledge a “rule-out” way of approaching these stratification models rather than a classical “rule-in” strategy. Moreover, the current genetic panorama regarding possible molecular adjunct markers for PPGL malignancy is reviewed. A combined histological and genetic approach will be needed to fully elucidate the malignant potential of these tumors.

Catecholamine-Synthesizing Enzymes in Pheochromocytoma and Extraadrenal Paraganglioma

In chromaffin cells, tyrosine hydroxylase (TH), aromatic L-amino acid decarboxylase (AADC), dopamine β-hydroxylase (DBH), and phenylethanolamine N-methyltransferase (PNMT) are mainly involved in catecholamine synthesis. In this study, we evaluated the association between the status of catecholamine-synthesizing enzymes and histopathological features of pheochromocytoma and extraadrenal paraganglioma with special emphasis upon their postoperative clinical behavior. Immunohistochemical evaluation of TH, DBH, AADC, PNMT, Ki 67, and S-100 was performed in 29 pheochromocytoma and 10 extraadrenal paraganglioma and one lymph node harboring metastatic pheochromocytoma. Among these cases, metastasis was subsequently developed in three cases. Urinary normetanephrine (U-NM) levels were significantly higher in clinical metastatic cases than non-metastatic ones. Ki 67 labeling index was significantly higher in both clinical metastatic cases and the Adrenal Gland Scaled Score (PASS) score of ≧ 4 cases than PASS < 4 cases, although this score was originally used in pheochromocytoma. H-score of AADC and DBH were significantly lower in PASS ≧ 4 cases than those with < 4 cases, and in the cases associated with intratumoral necrosis (n = 4), the presence of spindle shaped tumor cells (n = 4), and large nests of cells or diffuse growth (n = 5). Lower status of intratumoral AADC could be related to poor differentiation of tumor cells in both catecholamine production and morphology and could be related to aggressive biological behavior of both pheochromocytoma and extraadrenal paraganglioma.