Pheochromocytomas and Paragangliomas: Clinical and Genetic Approaches

Pheochromocytoma/Paraganglioma Syndrome Type 1 Presenting with Atypical Symptoms and a Novel Pathogenic Variant in the SDHD Gene: A Case Report

This case report presents a 10-year-old patient diagnosed with pheochromocytoma/paraganglioma syndrome type 1 (PPGL1), underlined by a novel heterozygous pathogenic variant (c.154_161del, p.ser52Profster14) in the SDHD gene. Initially, the patient manifested symptoms unusual for pheochromocytoma, including polyuria and polydipsia; however, further diagnostic investigations revealed a pheochromocytoma (PCC) tumor in the adrenal gland. Subsequently, whole exome sequencing (WES) test identified a pathogenic frameshift variant in the SDHD gene, strongly suggestive of PPGL1. This study highlights the importance of considering atypical symptoms in diagnosing rare pediatric pheochromocytoma/paraganglioma tumors and underscores the value of genetic testing in identifying underlying genetic causes, thereby facilitating personalized management of the condition.

Neurofibromatosis Type 1: Optimizing Management with a Multidisciplinary Approach

Neurofibromatosis Type I (NF1) is a complex genetic condition that affects multiple organ systems and presents a unique set of challenges for clinicians in its management. NF1 is a tumor predisposition syndrome that primarily affect the peripheral and central nervous systems via the impact of haploinsufficiency upon neural crest lineage cells including Schwann cells, melanocytes, fibroblasts, etc. NF1 can further lead to pathology of the skin, bones, visual system, and cardiovascular system, all of which can drastically reduce a patient's quality of life (QOL). This review provides a comprehensive examination of the many specialties required for the care of patients with Neurofibromatosis Type 1 (NF1). We delve into the pathogenesis and clinical presentation of NF1, highlighting its diverse manifestations and the challenges they pose in management. The review underscores the importance of a multidisciplinary approach to NF1, emphasizing how such an approach can significantly improve patient outcomes and overall QOL. Central to this approach is the role of the NF expert, who guides a multidisciplinary team (MDT) comprising healthcare professionals from many areas of expertise. The MDT collaboratively addresses the multifaceted needs of NF1 patients, ensuring comprehensive and personalized care. This review highlights the need for further investigation to optimize the workflow for NF1 patients in an MDT setting, and to improve implementation and efficacy.

A rare case report: vaginal paraganglioma

Vaginal paraganglioma (VP), usually solitary and primary, is a rare adrenal type paraganglioma derived from the anterior neural crest, and can be classified as a functional or non-functional tumor. Only 10 cases of VP have been reported since 1955. Herein, we report an unusual case of a 39-year-old female VP patient with symptoms of hypercatecholaminism and a family history of hypertension. After preoperative control of blood pressure with an alpha-receptor blocker, laparoscopic surgery was performed. The blood pressure fluctuated after touching the tumor intraoperatively, and the tumor was successfully and completely removed under anesthesia by surgery. Postoperative pathology confirmed the diagnosis. The clinical characteristics, auxiliary examination, morphological and pathological immunohistochemical characteristics, and perioperative treatment of VP are analyzed, and the literature of the previous 10 cases is reviewed, so as to help further understand VP and provide clinical guidance.

Sclerosing Paragangliomas: Correlations of Histological Features with Patients' Genotype and Vesicular Monoamine Transporter Expression

Paragangliomas and pheochromocytomas are rare neuroendocrine tumors, carrying a germ-line mutation in 40% patients. Sclerosis is a rare histological feature in these tumors. We investigated the possible correlations between histological findings, first sclerosis, immunoreactivity for vesicular catecholamine transporters (VMAT1/VMAT2) and patients' genotype in a consecutive series of 57 tumors (30 paragangliomas and 27 pheochromocytomas) from 55 patients. The M-GAPP grading system, sclerosis (0-3 scale) and VMAT1/VMAT2 (0-6 scale) immunoreactivity scores were assessed. Germ-line mutations of Succinate Dehydrogenase genes, RET proto-oncogene and Von Hippel Lindau tumor suppressor gene were searched. A germ-line mutation was found in 25/55 (45.5%) patients, mainly with paraganglioma (N = 14/30, 46,66%). Significant (score ≥ 2) tumor sclerosis was found in 9 (16.1%) tumors, i.e., 7 paragangliomas and 2 pheochromocytomas, most of them (8/9) from patients with a germ-line mutation. M-GAPP score was higher in the mutation status (in 76% of patients involving the SDHx genes, in 12% the RET gene and in the remaining 12% the VHL gene) and in tumors with sclerosis (p < 0.05). Spearman's rank correlation showed a strong correlation of germ-line mutations with M-GAPP (p < 0.0001) and sclerosis (p = 0.0027) scores; a significant correlation was also found between sclerosis and M-GAPP scores (p = 0.029). VMAT1 expression was higher in paragangliomas than in pheochromocytomas (p = 0.0006), the highest scores being more frequent in mutation-bearing patients' tumors (p < 0.01). VMAT2 was highly expressed in all but two negative tumors. Sclerosis and VMAT1 expression were higher in paragangliomas than in pheochromocytomas; tumor sclerosis, M-GAPP and VMAT1 scores were associated to germ-line mutations. Sclerosis might represent a histological marker of tumor susceptibility, prompting to genetic investigations in paragangliomas.

Case Report: Composite pheochromocytoma with ganglioneuroma component: A report of three cases

Composite pheochromocytoma (CP) is a very rare tumor originating from neural crest cells, predominantly composed of pheochromocytoma (PCC), a chromaffin cell tumor arising in adrenal medulla, and ganglioneuroma, a tumor derived from autonomic ganglion cells of the nervous system. Moreover, CP may be present in the hereditary syndromes of which pheochromocytoma is part. Literature offers scarce data on this subject, and particularly about its biological behavior, clinical evolution, and molecular profile. We report the phenotype and outcome of three cases of CP (PCC and ganglioneuroma components), followed up at the Endocrine Service of the Clementino Fraga Filho University Hospital, Federal University of Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil. Two nonsyndromic patients (cases 1 and 2) were negative to germline mutations in genes VHL, SDHB, SDHC, SDHD, SDHAF2, TMEM127, and MAX, while the third case (case 3) had clinical diagnosis of neurofibromatosis syndrome. Cases 1, 2, and 3 were diagnosed at 29, 39, and 47 years old, respectively, and were followed up for 3, 17, and 9 years without no CP recurrence. All cases had apparent symptoms of catecholaminergic excess secreted by PCC. Ganglioneuroma, the neurogenic component present in all three cases, had a percentage representation ranging from 5% to 15%. Tumors were unilateral and large, measuring 7.0 cm × 6.0 cm × 6.0 cm, 6.0 cm × 4.0 cm × 3.2 cm, and 7.5 cm × 6.0 cm × 4.5 cm, respectively. All cases underwent adrenalectomy with no recurrence, metastasis, or development of contralateral tumor during follow-up. Genetic testing has been scarcely offered to CP cases. However, a similar frequency of genetic background is found when compared with classic PCC, mainly by the overrepresentation of NF1 cases in the CP subset. By literature review, we identified a notorious increase in cases reported with CP in the last decade, especially in the last 3 years, indicating a recent improvement in the diagnosis of this rare disorder in clinical practice.

SDHB-Associated Paraganglioma Syndrome in Africa-A Need for Greater Genetic Testing

A germline mutation is identified in almost 40% of pheochromocytoma/paraganglioma (PPGL) syndromes. Genetic testing and counseling are essential for the management of index cases as well as presymptomatic identification and preemptive management of affected family members. Mutations in the genes encoding the mitochondrial enzyme succinate dehydrogenase (SDH) are well described in patients with hereditary PPGL. Among patients of African ancestry, the prevalence, phenotype, germline mutation spectrum, and penetrance of SDH mutations is poorly characterized. We describe a multifocal paraganglioma in a young African male with an underlying missense succinate dehydrogenase subunit B (SDHB) mutation and a history of 3 first-degree relatives who died at young ages from suspected cardiovascular causes. The same SDHB mutation, Class V variant c.724C>A p.(Arg242Ser), was detected in one of his asymptomatic siblings. As there are limited data describing hereditary PPGL syndromes in Africa, this report of an SDHB-associated PPGL is a notable contribution to the literature in this growing field. Due to the noteworthy clinical implications of PPGL mutations, this work highlights the existing need for broader genetic screening among African patients with PPGL despite the limited healthcare resources available in this region.

Clinicopathological, immunophenotypic and genetic studies of mediastinal paragangliomas†

OBJECTIVES

Paragangliomas have unique features in the mediastinum, in part due to their location. Because of their paucity, they have not been thoroughly investigated. We studied the clinical, pathological, immunohistochemical and molecular features of mediastinal paragangliomas.

METHODS

Immunohistochemistry, next-generation sequencing mutation panel and the Oncoscan assay were performed.

RESULTS

Twenty-four patients with mediastinal paraganglioma (7 men, 29.2%) had a median age of 45.5 years (19.8-72.2). Twenty-one (87.5%) paragangliomas were completely resected. Six (of 24, 25.0%) tumours were considered metastatic. Mitotic activity occurred in 11 (of 24, 45.8%) paragangliomas. Programmed death-ligand 1 (PD-L1) (n = 23) was expressed in 6 (26%) patients in 10% (n = 2) and 1% (n = 4) of tumour cells, respectively. SDHB expression was lost in 19 (of 22, 86.4%) cases. ATRX expression was lost in 11 (of 23, 47.8%) cases. Next-generation sequencing revealed a single pathogenic mutation in 10 (of 19) specimens including SDHB (n = 4), SDHD (n = 6), SDHC (n = 1), ATRX (n = 1), and ≥2 mutations in 2 cases [SDHC and TERT (n = 1); SDHB, ATRX and TP53 (n = 1)]. Germline mutation analysis revealed the same succinate dehydrogenase mutation (or lack thereof) as identified in the paraganglioma in 11 (of 12) cases. During a median follow-up (n = 21) of 4.8 years (0.8-14.9), 3 patients developed metastases; 4 patients died, at least 1 of disease.

CONCLUSIONS

Mediastinal paragangliomas can be associated with morbidity and mortality. Many mediastinal paragangliomas have been reported to be associated with syndromes such as multiple endocrine neoplasia, von Hippel-Lindau or succinate dehydrogenase syndrome with mutation profiles dominated by alterations in genes associated with these syndromes.

Laparoscopic resection of a large clinically silent paraganglioma at the organ of Zuckerkandl: a rare case report and review of the literature

Background

Large paraganglioma of the Zuckerkandl organ (POZ) is extremely rare. The patient can occasionally be paucisymptomatic, further obscuring the diagnosis and carrying high mortality. Recommended treatment for large paraganglioma (PGL) is open surgical removal. We report a case of successful laparoscopic resection of a large POZ with normal blood pressure in a 45-year-old man.

Case presentation

A 45-year-old man was hospitalized because of hyperglycemia. Computed tomography of the abdomen and the serum and urinary catecholamine levels confirmed the diagnosis of large POZ. But his blood pressure was normal and he underwent laparoscopic tumor excision successfully. During 6 months follow-up after laparoscopy, serum and urinary catecholamines were normal but glycaemia remained high level. DNA analysis of the succinate dehydrogenase complex subunits B (SDHB) and SDHD revealed no mutation.

Conclusions

POZ is an unusual mass and preoperative diagnosis can be difficult in clinically silent cases. PGL cannot be excluded in patients with normal blood pressure. Even a large POZ can be excised laparoscopically by following proper techniques.

Hypersecretory Paraganglioma Presenting as Acute Aortic Dissection

Abrupt, transient, and severe hypertension evoked by catecholamine-secreting tumors has the potential to manifest as acute aortic dissection. We report the successful, multidisciplinary management of an insidious, extra-adrenal, functional paraganglioma, suddenly presenting as acute aortic dissection. (Level of Difficulty: Beginner.).

Genetics and imaging of pheochromocytomas and paragangliomas: current update

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare, heterogeneous neuroendocrine neoplasms of the autonomous nervous system of chromaffin cell origin that may arise within the adrenal medulla (PCCs) or the sympathetic and parasympathetic paraganglia (PGLs). Currently referred to by the umbrella term pheochromocytomas-paragangliomas (PPGLs), these distinct tumors are characterized by specific histopathology as well as biological and clinical profiles. PPGLs may occur as part of hereditary syndromes (40% of cases) or as sporadic tumors. Currently, there are 12 different hereditary syndromes with characteristic genetic abnormalities, at least 15 well-characterized driver genes and distinct tumor metabolic pathways. Based on the Cancer Genome Atlas (TCGA) taxonomic schemata, PPGLs have been classified into three main clusters of specific genetic mutations and tumor pathways with clinical, biochemical, and prognostic implications. Imaging plays a pivotal role in the initial diagnosis, tumor characterization, evaluation of treatment response, and long-term surveillance. While MDCT and MRI help in the anatomic localization, SPECT, and PET using different radiotracers are crucial in the functional assessment of these tumors. Surgery, chemotherapy, and radiotherapy are currently available treatment options for PPGLs; antiangiogenic drugs are also being used in treating metastatic disease. Evolving knowledge regarding the different genetic abnormalities involved in the pathogenesis of PPGLs has identified potential therapeutic targets that may be utilized in the discovery of novel drugs.

A novel &lt;italic&gt;RET&lt;/italic&gt; mutation identified in a patient with pheochromocytoma and renal cell carcinoma

Pheochromocytomas might be sporadic or genetic. Genetic pheochromocytoma is associated with multiple endocrine neoplasia (MEN) type 2A, MEN type 2B, and von Hippel-Lindau (VHL) disease. RET mutations are identified in more than 90% of index cases of MEN2 and familial medullary thyroid cancer and in about 4–12% of apparent sporadic cases. Here, we report a 54-year-old man presenting with pheochromocytoma and renal cell carcinoma, who was identified as having a novel missense RET mutation.

Role of VHL, HIF1A and SDH on the expression of miR-210: Implications for tumoral pseudo-hypoxic fate

The hypoxia-inducible factor 1α (HIF-1α) and its microRNA target, miR-210, are candidate tumor-drivers of metabolic reprogramming in cancer. Neuroendocrine neoplasms such as paragangliomas (PGLs) are particularly appealing for understanding the cancer metabolic adjustments because of their associations with deregulations of metabolic enzymes, such as succinate dehydrogenase (SDH), and the von Hippel Lindau (VHL) gene involved in HIF-1α stabilization. However, the role of miR-210 in the pathogenesis of SDH-related tumors remains an unmet challenge. Herein is described an in vivo genetic analysis of the role of VHL, HIF1A and SDH on miR-210 by using knockout murine models, siRNA gene silencing, and analyses of human tumors. HIF-1α knockout abolished hypoxia-induced miR-210 expression in vivo but did not alter its constitutive expression in paraganglia. Normoxic miR-210 levels substantially increased by complete, but not partial, VHL silencing in paraganglia of knockout VHL-mice and by over-expression of p76del-mutated pVHL. Similarly, VHL-mutated PGLs, not those with decreased VHL-gene/mRNA dosage, over-expressed miR-210 and accumulate HIF-1α in most tumor cells. Ablation of SDH activity in SDHD-null cell lines or reduction of the SDHD or SDHB protein levels elicited by siRNA-induced gene silencing did not induce miR-210 whereas the presence of SDH mutations in PGLs and tumor-derived cell lines was associated with mild increase of miR-210 and the presence of a heterogeneous, HIF-1α-positive and HIF-1α-negative, tumor cell population. Thus, activation of HIF-1α is likely an early event in VHL-defective PGLs directly linked to VHL mutations, but it is a late event favored but not directly triggered by SDHx mutations. This combined analysis provides insights into the mechanisms of HIF-1α/miR-210 regulation in normal and tumor tissues potentially useful for understanding the pathogenesis of cancer and other diseases sharing similar underpinnings.

Endocrine Tumors Causing Arterial Hypertension: Pathophysiological Mechanisms and Clinical Implications

Some tumors are a relatively rare and amendable cause of hypertension, often associated with a higher cardiovascular morbidity and mortality, as compared with that of both general population and patients with essential hypertension. This worse prognosis is not entirely related to blood pressure increase, because the release of substances from the tumor can directly influence blood pressure behavior. Diagnostic approach is challenging and needs a deep knowledge of the different neuro-hormonal and genetic mechanisms determining blood pressure increase. Surgical tumor removal can, but not always, cause blood pressure normalization, depending on how early was tumor detection, since a long-standing history of hypertension is often associated with a much weaker effect on blood pressure. Moreover, target organ damage can be affected by the substances themselves released by the tumors as well as by tumor removal. In this review we consider the phenotype and genetic features of patients with tumor-induced hypertension and focus on their diagnostic work-up.

Treatment of pheochromocytomas and paragangliomas: genetic approach?

Pheochromocytomas (PHEOs) and paragangliomas (PGLs) are neuroendocrine tumors derived from the chromaffin tissue of the adrenal medulla or from extra-adrenal sympathetic and parasympathetic paraganglia. These tumors affect one in 2500–6500 people, with 500–1600 patients diagnosed annually in the USA. Its real incidence is likely to be much higher, and many patients may die undiagnosed. It is a rare cause of secondary hypertension, with an incidence of 0.1–0.6%. PHEOs are more common than PGLs, and 5–7% is related to hormonal secretion. The average age of diagnosis is 43 years, but 10–20% of PHEO/PGL patients are children, and the tumors are generally associated with genetic conditions. The worldwide consensus is that people with PHEOs/PGLs should undergo a mandatory genetic investigation, especially with multiple injuries and those who are younger. Although many PHEOs are sporadic and benign, approximately 30% of familial tumor cases have been identified. Multiple endocrine neoplasia type 2, von Hippel–Lindau syndrome and neurofibromatosis type 1 are classically linked to PHEO and mutations in succinate dehydrogenase complex subunits have been associated with familial forms. Our goal is to review various clinical syndromes in which PHEOs/PGLs are present, along with their therapeutic options.

Neuroendocrine Tumors of the Urinary Bladder According to the 2016 World Health Organization Classification: Molecular and Clinical Characteristics

Neuroendocrine neoplasms of the urinary bladder are a rare type of tumor that account for a small percentage of urinary bladder neoplasms. These tumors of the urinary bladder range from well-differentiated neuroendocrine neoplasms (carcinoids) to the more aggressive subtypes such as small cell carcinoma. Despite the rarity of the neuroendocrine tumors of the bladder, there has been substantial investigation into the underlying genomic, molecular, and the cellular alterations within this group of neoplasms. Accordingly, these findings are increasingly incorporated into the understanding of clinical aspects of these neoplasms. In this review, we provide an overview of recent literature related to the 2016 World Health Organization Classification of Neuroendocrine Tumors of the Urinary Bladder. Particular emphasis is placed on molecular alterations and recently described gene expression. The neuroendocrine tumors of the urinary bladder are subdivided into four subtypes. Similar to their pulmonary and other extrapulmonary site counterparts, these have different degrees of neuroendocrine differentiation and morphological features. The clinical aspects of four subtypes of neuroendocrine tumor are discussed with emphasis of the most recent developments in diagnosis, treatment, and prognosis. An understanding of molecular basis of neuroendocrine tumors will provide a base of knowledge for future investigations into this group of unusual bladder neoplasms.