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

Differences between Patients with Sporadic and Familial Pheochromocytoma-Is It Possible to Avoid Genetic Testing in Certain Patients?

BACKGROUND

Pheochromocytoma (PHEO) is a rare neuroendocrine tumour with a strong genetic link, which therefore may modify its clinical behaviour and prognosis. The aim of the study is to evaluate the epidemiological and clinical differences between patients with sporadic and familial PHEO, as well as the specific differences in the index cases.

METHODS

A retrospective analysis of 136 patients in a tertiary hospital (1984-2021). Epidemiological, clinical, and histological variables were analysed.

STATISTICS

SPSS 28.0 software was used. Univariate and multivariate logistic regression analyses were performed. p < 0.05 was considered statistically significant.

RESULTS

64.71% of the cases (n = 88) presented a genetic mutation (familial cases). Additionally, 32.39% (n = 23) corresponded to index cases and the rest to screening cases. The main differences between patients with familial and sporadic PHEO were age (OR = 0.93 (0.89-0.97)), blood pressure-related symptoms (OR = 0.22 (0.06-0.89)), bilaterality (OR = 15.49 (3.76-63.84)), and size (OR = 0.70 (0.54-0.92)). Among patients with sporadic PHEO and index cases, only bilaterality was significant (OR = 13.53 (1.24-144.34)).

CONCLUSIONS

Patients with familial PHEO diagnosed by screening differ from sporadic cases in terms of age, clinical features, and size. However, patients with sporadic PHEO only differ from index cases by a lower presence of bilaterality, which reaffirms the importance of genetic screening of patients with PHEO and their relatives.

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.

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.

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.

An Unexpected Death Due to a Subclinical Pheochromocytoma After an Induced Abortion

ABSTRACT

Deaths due to hypertensive crisis can be unexplained because of the impossibility to identify-before the decease-the specific cause of the crisis. In these cases, autopsy and microscopic examinations are needed. It can happen that the request to conduct these examinations can be submitted to forensic pathologists by prosecutors to ascertain medical malpractice claims. Indeed, we report the case of a 36-year-old woman who died after a minimally invasive medical procedure because of the occurrence of a severe hypertensive crisis. After death, the woman's relatives raised formal complaint for medical malpractice. For this reason, the prosecutor ordered to perform an autopsy. Examining the abdominal cavity, the forensic pathologists identified the left adrenal gland as expanded; in correspondence with organ's medulla, there was a gray and noncapsulated mass. Immunohistochemistry was performed: the microscopic samples were diffusely positive for chromogranin A, suggesting the diagnosis of a subclinical pheochromocytoma. In light of the above, medical malpractice was excluded. This case highlights that forensic pathologists should be aware that, in case of unexpected deaths due to hypertensive crisis, adrenal glands should be always accurately evaluated, performing specific immunohistochemistry study to exclude the presence of a pheochromocytoma.

PD-L1 expression and association with genetic background in pheochromocytoma and paraganglioma

Metastatic pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors associated with poor prognosis and limited therapeutic options. Recent advances in oncology-related immunotherapy, specifically in targeting of programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) pathways, have identified a new treatment potential in a variety of tumors, including advanced and rare tumors. Only a fraction of patients being treated by immune checkpoint inhibitors have shown to benefit from it, displaying a need for strategies which identify patients who may most likely show a favorable response. Building on recent, promising outcomes in a clinical study of metastatic PPGL using pembrolizumab, a humanized IgG4κ monoclonal antibody targeting the PD-1/PD-L1 pathway, we examined PD-L1 and PD-L2 expression in relation to oncogenic drivers in our PPGL patient cohort to explore whether expression can predict metastatic potential and/or be considered a predictive marker for targeted therapy. We evaluated RNA expression in the NIH cohort of 48 patients with known genetic predisposition (sporadic; pseudohypoxia: SDHB, VHL, EPAS1, EGLN1; kinase signaling: RET, NF1) and 6 normal medulla samples (NAM). For comparison, 72 PPGL samples from The Cancer Genome Atlas (TCGA) were used for analysis of gene expression based on the variant status (pseudohypoxia: SDHB, VHL, EPAS1, EGLN1; kinase signaling: NF1, RET). Expression of PD-L1 was elevated in the PPGL cohort compared to normal adrenal medulla, aligning with the TCGA analysis, whereas PD-L2 was not elevated. However, expression of PD-L1 was lower in the pseudohypoxia cluster compared to the sporadic and the kinase signaling subtype cluster, suggesting that sporadic and kinase signaling cluster PPGLs could benefit from PD-1/PD-L1 therapy more than the pseudohypoxia cluster. Within the pseudohypoxia cluster, expression of PD-L1 was significantly lower in both SDHB- and non-SDHB-mutated tumors compared to sporadic tumors. PD-L1 and PD-L2 expression was not affected by the metastatic status. We conclude that PD-L1 and PD-L2 expression in our cohort of PPGL tumors was not linked to metastatic behavior, however, the presence of PPGL driver mutation could be a predictive marker for PD-L1-targeted therapy and an important feature for further clinical studies in patients with PPGL.