Precision Medicine in Phaeochromocytoma and Paraganglioma

Phaeochromocytoma and paraganglioma

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

Ultrastructural features of tumor-associated mast cells in parasympathetic paragangliomas (chemodectomas) of the neck

The mechanisms of the pathogenesis of neck paraganglioma (PGL) and the possible role of mast cells (MCs) in its development and metastasis are still poorly understood. We analyzed MCs' morphologic characterization, activation, and the properties of their cytoplasmic/released granules in PGLs, using light and transmission electron microscopy. Paragangliomas showed a large tumor-associated MC population both in the connective tissue layers of the tumor and between the tumor cells. Notably, MCs were presented by a high expression of specific proteases, size variation, polymorphism, and variable ultrastructural phenotype of granules. A massive number of granules were released surrounding the degranulated MCs while the integrity of MC membrane was maintained. Granules were electron-dense with or without a membrane, ranging from 0.2 to 0.8 μm in diameter. MC plasmalemma was not found at the site of MC-collagen fibrils contact, whereas the secretome and fibrils were directly contacted. We observed direct and mediator-based interactions between MCs and paraganglioma cells. The latter preserved their membrane integrity when MC granules were not in proximity. The effects of the MC secretome on the paraganglioma microenvironment demonstrated its pathogenetic role in tumor progression and allow its application to new diagnostic criteria and the development of protocols for personalized therapy. RESEARCH HIGHLIGHTS: Ultrastructural analysis reveals novel regulatory effects of mast cells via diverse secretory pathways on the pathogenesis of parasympathetic paraganglioma, including fibrous extracellular matrix remodeling and mediator-based interactions between MCs and cells of the tumor microenvironment.

Esmolol's Role in Hemodynamic Management During Pheochromocytoma Surgery: A Comprehensive Review

Pheochromocytoma (PCC) surgery presents significant challenges due to the hemodynamic instability induced by catecholamine release. Effective perioperative management is essential to minimize complications and ensure optimal outcomes. This comprehensive review examines the role of esmolol, a short-acting beta-blocker, in hemodynamic stabilization during PCC surgery. We provide an overview of the pathophysiology of PCC, highlighting the cardiovascular effects of excessive catecholamines. Challenges in perioperative management and the need for effective hemodynamic control are discussed. The pharmacology and mechanisms of action of esmolol are outlined, along with evidence from clinical studies supporting its use in PCC surgery. Comparative analyses with other hemodynamic agents are presented, along with recommendations for optimizing esmolol administration and monitoring. Key findings include the ability of esmolol to attenuate catecholamine-induced hypertension and tachycardia, thereby promoting hemodynamic stability and reducing the risk of intraoperative cardiovascular crises. Implications for clinical practice include the incorporation of esmolol into perioperative management protocols and the importance of multidisciplinary collaboration. Future research directions include further elucidating optimal dosing regimens, comparative effectiveness studies, and exploring novel therapeutic approaches. Collaboration among clinicians, researchers, and pharmaceutical companies is essential to advance the care of patients undergoing surgery for PCC.

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.

Development and validation of a novel nomogram predicting pseudohypoxia type pheochromocytomas and paragangliomas

PURPOSE

Pseudohypoxia type (PHT) pheochromocytomas and paragangliomas (PPGLs) are more likely to metastasize and have a poor prognosis. However, application of genetic tests has many restrictions. The study aims to establish a novel nomogram for predicting the risk of PHT PPGLs.

METHODS

This retrospective cross-sectional study included 242 patients with pathology confirmed PPGLs in one tertiary care center in China in 2010-2021. Clinical and biochemical characteristics were collected. Next-generation sequencing was performed in all PPGLs patients for detection of mutation. Univariate and multivariable logistic regression analyses were used to select risk factors for constructing the nomogram. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the discrimination of the nomogram and the calibration curve was performed.

RESULTS

Four variables including age ≤ 35 years, hypertension, 24 h urinary output of urinary vanillylmandelic acid (VMA) ≥ 100 umol/24 h and urinary 17-ketosteroide (17 KS) ≤ 50 umol/24 h levels were independently associated with PHT PPGLs in the logistic regression analysis and were included in the nomogram. The nomogram showed a good discrimination performance with AUC of 0.829 [95% confidence interval (CI), 0.767-0.891] in the training set and 0.797 (95%CI, 0.659-0.935) in the validation set, respectively. The calibration curve showed a bias-corrected AUC of 0.809 vs. 0.795, and a Hosmer-Lemeshow (H-L) test yielded a p value of 0.801 vs. 0.885, indicating the nomogram's good ability to distinguish PHT PPGLs from non-PHT PPGLs.

CONCLUSION

Our study has proposed a novel nomogram for individualized prediction of the PHT PPGLs, which may make contributions to guide the patients' personalized management, follow-up, and treatment.

Special Issue: Present and Future of Personalised Medicine for Endocrine Cancers

Major technological advances in genomics have made it possible to identify critical genetic alterations in cancer, rendering oncology well along the path to personalised cancer medicine [...].