Genetics and clinical characteristics of hereditary pheochromocytomas and paragangliomas

Pheochromocytoma-Paraganglioma Syndrome: A Multiform Disease with Different Genotype and Phenotype Features

Pheochromocytoma and paraganglioma (PPGL) are rare tumors derived from the adrenal medulla and extra-adrenal chromaffin cells. Diagnosis is often challenging due to the great variability in clinical presentation; the complexity of management due to the dangerous effects of catecholamine excess and the potentially malignant behavior require in-depth knowledge of the pathology and multidisciplinary management. Nowadays, diagnostic ability has certainly improved and guidelines and consensus documents for treatment and follow-up are available. A major impulse to the development of this knowledge has come from the new findings on the genetic and molecular characteristics of PPGLs. Germline mutation in susceptibility genes is detected in 40% of subjects, with a mutation frequency of 10-12% also in patients with sporadic presentation and genetic testing should be incorporated within clinical care. PPGL susceptibility genes include "old genes" associated with Neurofibromatosis type 1 (NF1 gene), Von Hippel Lindau syndrome (VHL gene) and Multiple Endocrine Neoplasia type 2 syndrome (RET gene), the family of SDHx genes (SDHA, SDHB, SDHC, SDHD, SDHAF2), and genes less frequently involved such as TMEM, MAX, and FH. Each gene has a different risk of relapse, malignancy, and other organ involvement; for mutation carriers, affected or asymptomatic, it is possible to define a tailored long-life surveillance program according to the gene involved. In addition, molecular characterization of the tumor has allowed the identification of somatic mutations in other driver genes, bringing to 70% the PPGLs for which we know the mechanisms of tumorigenesis. This has expanded the catalog of tumor driver genes, which are identifiable in up to 70% of patients Integrated genomic and transcriptomic data over the last 10 years have revealed three distinct major molecular signatures, triggered by pathogenic variants in susceptibility genes and characterized by the activation of a specific oncogenic signaling: the pseudo hypoxic, the kinase, and the Wnt signaling pathways. These molecular clusters show a different biochemical phenotype and clinical behavior; they may also represent the prerequisite for implementing customized therapy and follow-up.

Anesthesia Management in Hereditary Pheochromocytoma and Paraganglioma: Updated Insights into Clinical Features and Perioperative Care

Approximately 40% of pheochromocytoma and paraganglioma (PPGL) cases are familial, typically presenting earlier with more complex symptoms. This paper synthesizes literature and guidelines to inform on clinical characteristics and perioperative care for PPGL. Pheochromocytoma in von Hippel-Lindau (VHL) disease exhibits heightened secretion activity without significant perioperative hemodynamic changes. Tumors in multiple endocrine neoplasia type 2 (MEN2) have a stronger endocrine function, which may induce hemodynamic fluctuations during surgery. Therefore, pheochromocytoma screening is essential at all stages of MEN2. Neurofibromatosis type 1 (NF1) often presents multisystem lesions and can result in difficult airway. Pheochromocytoma should be evaluated when NF1 patients present hypertension. Pheochromocytoma and paraganglioma type 5 may present multiple lesions of pheochromocytoma or paraganglioma. In summary, hereditary PPGLs may present with severe lesions in other systems, beyond tumor function. A multi-disciplinary team (MDT) approach is often invaluable in perioperative management.

Recent discoveries of Sino-Caucasian differences in the genetics of phaeochromocytomas and paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) represent the highest degree of heritability of any known tumor types in humans. Previous studies have characterized a dramatic difference between Chinese and European Caucasians with regards to both genetics and clinical features of PPGLs. The proportion of PGLs in Chinese patients was higher than in Caucasians, and the prevalence of metastasis was much lower in Chinese patients. Compared with Caucasians, there were more pathogenic variants (PVs) found in HRAS and FGFR1, but less in NF1 and SDHB. There were less germline PVs found in Chinese patients. Importantly, in Chinese patients, there was a large proportion of PGLs with PVs found in HRAS and FGFR1, mostly with epinephrine-producing capacity. This finding provided solid evidence that genetics (cluster 1 vs. 2), rather than location (PCC vs. PGL), determines the catecholamine-producing phenotype. Besides, the lower prevalence of SDHB partially explained lower occurrence of metastatic lesions in Chinese patients. These findings underscore the importance of considering ethnic differences when evaluating PPGLs and patient outcomes.

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.

Stereotactic radiotherapy for head and neck paragangliomas: How long should we wait for treatment response?

BACKGROUND AND PURPOSE

Stereotactic radiotherapy (SRT) is an effective treatment for head & neck (H&N) paragangliomas. Nevertheless, the timeline for achieving a tumor-volume-reduction (TVR) remains unclear.

MATERIALS AND METHODS

Sixty-three cases with H&N paragangliomas received definitive SRT and were evaluated retrospectively. Statistical Package for the Social Sciences (SPSS) v23.0 (IBM, Armonk, NY, USA) was used for statistics.

RESULTS

Sixty-eight lesions were irradiated, with glomus jugulotympanicum being the most common location (44 %). Median tumor diameter and volume were 3 cm (range, 1-7.6 cm) and 15.4 cm3 (range,1-185 cm3), respectively. Median dose was 25 Gy (range, 12-37.5 Gy) in 5 fractions (range, 1-5 fractions). Median follow-up was 40 months (range, 3-184 months). Treatment response, evaluated at a median 4.6 months post-SRT (range: 3-11 months), revealed TVR in 26 cases (41 %). During follow-up, 13 additional cases showed TVR, resulting in an overall TVR rate of 62 %. The median duration for attaining TVR was 9 months (range, 3-36 months) after SRT, and TVR occurred ≥ 12 months in 42 % of cases. Patients without prior surgery (p = 0.03) and with a longer follow-up (p = 0.04) demonstrated a higher rate of TVR. The likelihood of TVR tends to increase as the SRT dose increases (p = 0.06). Overall local control (LC) rate was 100 %. No ≥ grade 3 acute or late toxicities were observed.

CONCLUSION

While SRT demonstrates an excellent LC rate for H&N paragangliomas, it's important to note that the response to treatment may require time. TVR may last beyond the initial year of treatment in a substantial proportion of patients.

Paraganglioma of the Neck: A Rare Case With Spinal Metastasis

Paragangliomas are rare neuroendocrine tumors that arise from the paraganglia, which are clusters of neuroendocrine cells associated with the autonomic nervous system. These tumors are commonly found in the adrenal medulla but can also occur in other locations outside the adrenal gland. Here, we present a case report of a slow-growing paraganglioma in the left neck with spinal metastasis in a 60-year-old man. This case highlights the importance of considering paraganglion tumors in the differential diagnosis of neck masses and the need for early diagnosis and management to prevent potential complications. Importantly, both the clinical picture and anatomical location of these tumors is important when determining treatment plans.

Tumor metabolism in pheochromocytomas: clinical and therapeutic implications

Pheochromocytomas and paragangliomas (PPGLs) have emerged as one of the most common endocrine tumors. It epitomizes fascinating crossroads of genetic, metabolic, and endocrine oncology, providing a canvas to explore the molecular intricacies of tumor biology. Predominantly rooted in the aberration of metabolic pathways, particularly the Krebs cycle and related enzymatic functionalities, PPGLs manifest an intriguing metabolic profile, highlighting elevated levels of oncometabolites like succinate and fumarate, and furthering cellular malignancy and genomic instability. This comprehensive review aims to delineate the multifaceted aspects of tumor metabolism in PPGLs, encapsulating genetic factors, oncometabolites, and potential therapeutic avenues, thereby providing a cohesive understanding of metabolic disturbances and their ramifications in tumorigenesis and disease progression. Initial investigations into PPGLs metabolomics unveiled a stark correlation between specific genetic mutations, notably in the succinate dehydrogenase complex (SDHx) genes, and the accumulation of oncometabolites, establishing a pivotal role in epigenetic alterations and hypoxia-inducible pathways. By scrutinizing voluminous metabolic studies and exploiting technologies, novel insights into the metabolic and genetic aspects of PPGLs are perpetually being gathered elucidating complex interactions and molecular machinations. Additionally, the exploration of therapeutic strategies targeting metabolic abnormalities has burgeoned harboring potential for innovative and efficacious treatment modalities. This review encapsulates the profound metabolic complexities of PPGLs, aiming to foster an enriched understanding and pave the way for future investigations and therapeutic innovations in managing these metabolically unique tumors.

Robotic Resection in Succinate Dehydrogenase Subunit B (SDHB)-Mutated Hereditary Paraganglioma: A Case Report of Two Patients and A Literature Review

Autosomal dominant hereditary paraganglioma-pheochromocytoma syndrome (HPPS) is a rare genetic disorder characterized by neuroendocrine tumor development associated with pathogenic variants in succinate dehydrogenase (SDH) enzyme complex genes. Particularly, HPPS linked to SDHB mutation poses a significant clinical challenge due to its association with aggressive tumor features and a high risk of malignancy. Our report underscores the diversity in the presentation of patients with SDHB-mutated paraganglioma and the feasibility of managing it with a minimally invasive surgical approach. In the first case, a 17-year-old female was diagnosed with a metabolically active, poorly differentiated extra-adrenal retroperitoneal paraganglioma that required challenging robotic resection. Cascade genetic testing revealed an SDHB mutation not only in her but also in three family members, pointing to the inherited nature of the syndrome. Conversely, the second case involves a 37-year-old male with an asymptomatic well-differentiated left paraaortic paraganglioma incidentally found during an unrelated medical examination. Robotic converted-to-open resection allowed the successful removal of the mass. Subsequent germline testing confirmed a deleterious SDHB mutation, initiating a process of familial cascade testing. Both patients remained symptom- and recurrence-free at 12 and six months, respectively. Through these cases, and supported by a literature review, we highlight the variable clinical presentations of HPPS, arising from the same genetic alteration. The successful application of minimally invasive surgical techniques, combined with genetic evaluation, emphasizes the necessity for a comprehensive, tailored approach to treatment and surveillance. This strategy not only addresses the immediate clinical needs but also fosters proactive management of at-risk family members, ensuring a multidisciplinary approach to this complex hereditary condition.

Paragangliomas and Anemia: Literature Review and Case Report

Paragangliomas are rare neuroendocrine tumors that arise from the extra-adrenal autonomic paraganglia, i.e., small organs consisting mainly of neuroendocrine cells that are derived from the embryonic neural crest and have the ability to secrete catecholamines. Paragangliomas can derive from either parasympathetic or sympathetic paraganglia. Most of the parasympathetic ganglia-derived paragangliomas are nonfunctional, and symptoms result from mass effect. Conversely, the sympathetic paragangliomas are functional and produce catecholamine. Although such patients could have symptoms similar to pheochromocytoma, mass effect symptoms, or non-specific symptoms, being benign tumors, they can also present with anemia, specifically iron-deficiency anemia. Considering that neoplastic pathology is chronically accompanied by moderate, normochromic, normocytic anemia, association between paragangliomas that are mostly benign but with a potential degree of malignancy and anemia is not as frequent as expected, with only 12 cases reported in the literature. We report a case of a 54-year-old female patient diagnosed with a paraganglioma of the carotid glomus accompanied by severe normochromic, normocytic anemia, which reached normal limits after excision of the paraganglioma.

Bilateral Pheochromocytoma and Paraganglioma Tumors Due to Von Hippel-Lindau Syndrome in a 15-Year-Old Boy: A Case Report

Pheochromocytomas and paragangliomas are catecholamine-secreting tumors that originate from chromaffin cells of the adrenal medulla and autonomic neural ganglia, respectively. Patients with pheochromocytomas and paragangliomas typically present with paroxysmal headache, sweating, tachycardia, and hypertension. Although most pheochromocytoma cases are sporadic, many of the cases occur as part of a genetic disorder. Here, we report the case of a 14-year-old male patient who presented with hypertension. Laboratory tests showed elevated levels of serum and urinary catecholamines, metanephrines, and chromogranin. Abdominal ultrasound and computed tomography studies revealed bilateral solid adrenal masses and an isolated splenic mass. Further assessment identified an underlying Von Hippel-Lindau syndrome. The patient was initially treated medically and later surgically. This case highlights the importance of always considering pheochromocytomas and paragangliomas as rare differentials of secondary hypertension, especially in the presence of episodic headaches, sweating, and tachycardia. Furthermore, screening for underlying genetic disorders, such as in our case, should be considered in cases of bilateral tumors, onset at a young age, and presence of extra-adrenal tumors.

Composite pheochromocytoma of the adrenal gland-a review of published cases

Composite pheochromocytoma (CP) is a rare adrenal tumor, composed of ordinary pheochromocytoma and neuroblastic components. There is a paucity of information in the literature regarding this entity. We report the case of a 56-year-old woman with a CP of the left adrenal gland with a ganglioneuroma component. A review of the published literature found 110 cases of CP. The median age was 51.5 (5.86) years, and 59/110 (53.6%) were female. Association with genetic predisposition syndromes was found in 22/110 (20%), the most common of which was neurofibromatosis type 1, in 15/110 (13.6%). The most common histologic type of the neuroblastic component was ganglioneuroma in 83/110 (75.5%). Twenty-seven cases reported SDHB immunohistochemistry results; none of which was positive. Nine patients (8.2%) presented/developed metastatic disease, and 9 patients (8.2%) died from disease. To our knowledge, this is the largest review describing clinical, histopathological, molecular, and prognostic features of CP.

Mediastinal Paraganglioma: A retrospective analysis of 51 cases

BACKGROUND

Paragangliomas are rarely found in the mediastinum, where they account for a small proportion of mediastinal masses. This study aimed to better characterize the presenting features and relevant aspects in optimizing the diagnosis and treatment of mediastinal paragangliomas.

METHODS

A computer-assisted search of electronic health records was performed to identify adult patients (≥18 years) who underwent evaluation for a primary mediastinal paraganglioma at Mayo Clinic between January 2000 and April 2022. Medical charts, laboratory tests and radiology images were reviewed to collect data.

RESULTS

The study included 51 patients, each with a single mediastinal paraganglioma. The median age was 47 years (IQR: 39-67), 67% females. Symptoms of catecholamine excess were manifest in 39% of patients, and 14% presented with mass effect, while the remaining 47% had no paraganglioma-related symptoms. Genetic testing was performed in 35 patients; 66% harbored a pathogenic variant in the succinate dehydrogenase enzyme complex. Most paragangliomas (71%) were in the middle mediastinum and showed uptake of intravenous contrast on chest imaging. Biopsies were performed in 30 (59%) patients; 27% were inconclusive and 10% resulted in major complications. Surgical resection occurred in 75%, primarily for relief of symptoms (50%) followed by proximity to critical structures (45%). Perioperative complications were common (66%), but there were no cases of local tumor recurrence during the follow-up period (median 8 years; IQR: 4-13).

CONCLUSION

Mediastinal paragangliomas are most located in the middle mediastinum and can often be diagnosed noninvasively using a combination of clinical, biochemical, and radiological features.

Case Report: Paraganglioma in the sellar region: longitudinal observation and surgical outcome

Background

Paraganglioma in the sellar region is an extremely rare entity, with a limited number of cases reported in the literature. Due to the paucity of clinical evidence, the diagnosis and treatment of paragangliomas in the sellar region remain challenging. Herein, we reported a case of sellar paraganglioma with parasellar and suprasellar extension. Particularly, the dynamic evolution of this benign tumor within a 7-year longitudinal observation was presented. Additionally, the relevant literature regarding sellar paraganglioma was comprehensively reviewed.

Case description

A 70-year-old woman presented with progressive visual deterioration and headache. Brain magnetic resonance imaging demonstrated a mass in the sellar region with parasellar and suprasellar extension. The patient refused surgical treatment. Seven years later, brain magnetic resonance imaging showed the lesion significantly progressed. Neurological examination revealed bilateral tubular contraction of visual fields. Laboratory examinations showed endocrine hormone levels were normal. Surgical decompression was performed via a subfrontal approach, and subtotal resection was achieved. Histopathological examination confirmed a diagnosis of paraganglioma. Postoperatively, she developed hydrocephalus, and ventriculoperitoneal shunting was performed. Eight months later, cranial CT showed no recurrence of the residual tumor, and the hydrocephalus had been relieved.

Conclusion

Paraganglioma occurring in the sellar region is rare, and the preoperative differential diagnosis is difficult. Owing to the infiltration to the cavernous sinus and internal carotid, complete surgical resection is usually impracticable. There has been no consensus regarding postoperative adjuvant radiochemotherapy for the tumor residue. In-situ recurrence and metastasis have been reported in the literature, and close follow-up is warranted.

Domain landscapes of somatic NF1 mutations in pheochromocytoma and paraganglioma

Pheochromocytoma and paraganglioma (PPGL), are rare neuroendocrine tumors arising from the adrenal medulla and extra-adrenal paraganglia, respectively. Up to about 60% are explained by germline or somatic mutations in one of the major known susceptibility genes e.g., inNF1,RET,VHL, SDHx,MAXandHRAS. Targeted Next Generation Sequencing was performed in 14 sporadic tumors using a panel including 26 susceptibility genes to characterize the mutation profile. A total of 6 germline and 8 somatic variants were identified. The most frequent somatic mutations were found in NF1(36%), four have not been reported earlier in PCC or PGL. Gene expression profile analysis showed that NF1 mutated tumors are classified into RTK3 subtype, cluster 2, with a high expression of genes associated with chromaffin cell differentiation, and into a RTK2 subtype, cluster 2, as well with overexpression of genes associated with cortisol biosynthesis. On the other hand, by analyzing the entire probe set on the array and TCGA data, ALDOC was found as the most significantly down regulated gene in NF1-mutated tumors compared to NF1-wild-type. Differential gene expression analysis showed a significant difference between Nt - and Ct-NF1 domains in mutated tumors probably engaging different cellular pathways. Notably, we had a metastatic PCC with a Ct-NF1 frameshift mutation and when performing protein docking analysis, Ct-NF1 showed an interaction with Nt-FAK suggesting their involvement in cell adhesion and cell growth. These results show that depending on the location of the NF1-mutation different pathways are activated in PPGLs. Further studies are required to clarify their clinical significance.

FAM193A is a positive regulator of p53 activity

Inactivation of the p53 tumor suppressor, either by mutations or through hyperactivation of repressors such as MDM2 and MDM4, is a hallmark of cancer. Although many inhibitors of the p53-MDM2/4 interaction have been developed, such as Nutlin, their therapeutic value is limited by highly heterogeneous cellular responses. We report here a multi-omics investigation of the cellular response to MDM2/4 inhibitors, leading to identification of FAM193A as a widespread regulator of p53 function. CRISPR screening identified FAM193A as necessary for the response to Nutlin. FAM193A expression correlates with Nutlin sensitivity across hundreds of cell lines. Furthermore, genetic codependency data highlight FAM193A as a component of the p53 pathway across diverse tumor types. Mechanistically, FAM193A interacts with MDM4, and FAM193A depletion stabilizes MDM4 and inhibits the p53 transcriptional program. Last, FAM193A expression is associated with better prognosis in multiple malignancies. Altogether, these results identify FAM193A as a positive regulator of p53.

Carotid body paraganglioma metastatic to spine causing cord compression: a case report

BACKGROUND

Carotid body tumors (CBTs) are rare neuroendocrine neoplasms arising near the carotid bifurcation with a reported incidence of 1 to 2 cases in 100,000 patients. Most CBTs are sporadic, benign, slow-growing, and non-secreting, but untreated CBTs can grow locally to compress the nearby blood vessels, esophagus, and airway. Regional metastases can occur in 5% to 10% of cases, but distant metastases are exceedingly rare, occurring in roughly 1-2% of cases. As such, the optimal treatment for metastatic CBTs is not well-defined. We report a rare case of a patient with CBT distant metastases causing spinal cord compression.

CASE PRESENTATION

A 40-year-old African American female presented with a right neck mass, headaches, vertigo, tinnitus, hoarseness, and dysphagia. Imaging demonstrated a Shamblin II right neck mass; subsequent transcervical resection and pathology showed a carotid body paraganglioma. The patient recurred locally near the carotid bifurcation, so she underwent Stereotactic Body Radiation Therapy to the recurrent right neck disease. She later re-presented with new onset bilateral lower extremity weakness, dysmetria, and numbness. She was found to have metastatic disease to the thoracic spine causing spinal cord compression. She underwent laminectomy, tumor resection, and posterior fixation followed by adjuvant radiation therapy. She was started on systemic therapy with sunitinib. She eventually progressed with metastatic disease to the right iliac bone, which was treated with palliative radiotherapy. Second line systemic therapy with capecitabine and temozolomide was started. At last follow up, the patient was asymptomatic with stable persistent disease.

CONCLUSIONS

Paragangliomas often exhibit a prolonged interval to the development of progression; locoregional recurrences or rare distant metastases have been reported to occur as many as 20 years from diagnosis. The natural course of CBTs in other cases as well as the present case call into question the idea that CBTs are truly benign; instead CBTs may be indolent tumors with metastatic potential. Treatment choices for CBTs include surgical resection, radiation therapy, and systemic therapy, though the optimal treatment regimen for metastatic CBTs is not well-defined. A more advanced understanding of CBT pathophysiology, disease classification, risk stratification, and treatment options is needed to improve outcomes for patients.

Multifocal Paraganglioma in Teenager Presenting With Hypertension

Pediatric hypertension represents a rare though increasingly common medical problem. When encountered, a workup to determine the etiology should be conducted. In this report, we detail an unusual case in which a teenager presenting with hypertension was found to have multifocal primary paragangliomas. We illustrate important considerations in management which include appropriate preoperative labs and imaging, collaboration with endocrinology for preoperative alpha-blockade, surgical management with close perioperative hemodynamic control, and genetic evaluation for all patients with paragangliomas.

Metastatic paraganglioma

A man in his 70s, with a history of a glomus jugulare paraganglioma diagnosed 18 years ago, presented with an unprovoked deep vein thrombosis (DVT). The paraganglioma had been treated by radiotherapy, and yearly scans had not shown any progression since treatment. A sclerotic focus in L4 vertebral body was reported on a CT scan of the neck and trunk which was done to exclude a neoplastic process being the precipitating factor for the DVT. Nuclear imaging showed multiple areas of bony uptake, suggestive of metastases. A bone biopsy of the left femur resulted positive for metastatic paraganglioma. A monthly intramuscular injection of octreotide 30 mg was prescribed.

SDHB exon 1 deletion: A recurrent germline mutation in Colombian patients with pheochromocytomas and paragangliomas

Pheochromocytomas (PCCs) and paragangliomas (PGLs) (known as PPGL in combination) are rare neuroendocrine tumors of the adrenal medulla and extra-adrenal ganglia. About 40% of the patients with PPGL have a hereditary predisposition. Here we present a case-series of 19 unrelated Colombian patients with a clinical diagnosis of PPGL tumors that underwent germline genetic testing as part of the Hereditary Cancer Program developed at the Instituto Nacional de Cancerología, Colombia (INC-C), the largest reference cancer center in the country. Ten of 19 patients (52.63%) were identified as carriers of a pathogenic/likely pathogenic (P/LP) germline variant in a known susceptibility gene. The majority of the P/LP variants were in the SDHB gene (9/10): one corresponded to a nonsense variant c.268C>T (p.Arg90*) and eight cases were found to be carriers of a recurrent CNV consisting of a large deletion of one copy of exon 1, explaining 42% (8/19) of all the affected cases. Only one additional case was found to be a carrier of a missense mutation in the VHL gene: c.355T>C (p.Phe119Leu). Our study highlights the major role of SDHB in Colombian patients with a clinical diagnosis of PGL/PCC tumors and supports the recommendation of including the analysis of large deletions/duplications of the SDHB gene as part of the genetic counselling to improve the detection rate of hereditary cases and their clinical care.

Nuclear and mitochondrial DNA alterations in pheochromocytomas and paragangliomas, and their potential treatment

Mitochondrial DNA (mtDNA) alterations have been reported in different types of cancers and are suggested to play important roles in cancer development and metastasis. However, there is little information about its involvement in pheochromocytomas and paragangliomas (PCCs/PGLs) formation. PCCs and PGLs are rare endocrine tumors of the chromaffin cells in the adrenal medulla and extra-adrenal paraganglia that can synthesize and secrete catecholamines. Over the last 3 decades, the genetic background of about 60% of PCCs/PGLs involving nuclear DNA alterations has been determined. Recently, a study showed that mitochondrial alterations can be found in around 17% of the remaining PCCs/PGLs. In this review, we summarize recent knowledge regarding both nuclear and mitochondrial alterations and their involvement in PCCs/PGLs. We also provide brief insights into the genetics and the molecular pathways associated with PCCs/PGLs and potential therapeutical targets.

Other Less Prevalent Tumors of the Central Nervous System

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Bladder paraganglioma, gastrointestinal stromal tumor, and SDHB germline mutation in a patient with Carney-Stratakis syndrome: A case report and literature review

Background

Carney-Stratakis syndrome (CSS) is a rare dyad of paraganglioma (PGL)/pheochromocytoma (PHEO) and gastrointestinal stromal tumor (GIST). PGLs are neuroendocrine tumors of neural crest origin which are mostly found in the head, neck, and retroperitoneal space. GISTs are the most common mesenchymal tumors of the digestive tract, usually caused by KIT/PDGFRA mutations. Here, we reported a case of CSS with unusual bladder PGL and succinate dehydrogenase (SDH) deficient GIST due to a germline mutation in SDH-subunit B (SDHB) gene.

Case presentation

A 39-year-old female patient initially diagnosed with gastric GIST and isolated pelvic metastasis was eventually found to be CSS with bladder PGL and SDH-deficient GIST after surgery. This patient underwent resection of gastric and bladder tumors, and postoperative pathology confirmed the diagnosis of CSS. According to the next-generation sequencing (NGS), the patient carried a germline mutation in the SDHB gene, which was the cause of the disorder. The patient had no tumor recurrence with regular follow-up in 10 months.

Conclusions

CSS is an autosomal genetic disorder with no gender difference in incidence, and PGLs are more frequent than GISTs. SDH germline mutation is the molecular biological mechanism of CSS while the most common type is SDHB mutation. The unique mechanism of tumorigenesis including hypoxia and hypermethylation caused by SDH deficiency renders target therapy with tyrosine kinase inhibitors ineffective, therefore complete surgical resection is the optimal treatment in the absence of tumor metastases.

Spinal paraganglioma at the conus medullaris mimicking schwannoma: A case report

Background

Paragangliomas of the spine are extremely rare, and they should be considered in the differential diagnosis of spinal tumors due to its overlapping clinical and radiological features with many spinal tumors.

Case report

In this article, we present a 30-year-old lady who presented with low back pain and radicular neuropathic pain at L1 dermatome which was intractable to medical surgery. Her magnetic resonance imaging (MRI) of the lumbosacral spine revealed a T1 isointense, T2 heterogeneously hyperintense intradural extramedullary lesion at the conus medullaris with strong homogenous enhancement on contrast administration. The lesion was surgically excised completely with L1 laminectomy, and the histopathological picture was suggestive of paraganglioma. The patient's complaints resolved fully postoperatively, and there was no evidence of recurrence on long-term follow-up.

Conclusion

Due to the absence of pathognomonic clinical or radiological features of paragangliomas, they should be taken into consideration in the differential diagnosis of spinal tumors. They share similar clinical and radiological features of schwannomas, ependymomas, and hemangioblastomas. The diagnosis is usually made postoperatively based on histopathological examination.

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Paragangliomas overlap the clinical and radiological features with other tumors.

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Diagnosis is made postoperatively based on histopathological examination.

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It should be considered in the differential diagnosis of spinal tumors.

Observational study of population genomic screening for variants associated with endocrine tumor syndromes in a large, healthcare-based cohort

BACKGROUND

In current care, patients' personal and self-reported family histories are primarily used to determine whether genetic testing for hereditary endocrine tumor syndromes (ETS) is indicated. Population genomic screening for other conditions has increased ascertainment of individuals with pathogenic/likely pathogenic (P/LP) variants, leading to improved management and earlier diagnoses. It is unknown whether such benefits occur when screening broader populations for P/LP ETS variants. This manuscript assesses clinical utility outcomes of a large, unselected, healthcare-based genomic screening program by describing personal and family history of syndrome-related features, risk management behaviors after result disclosure, and rates of relevant post-disclosure diagnoses in patient-participants with P/LP ETS variants.

METHODS

Observational study of individuals informed of a P/LP variant in MEN1, RET, SDHAF2, SDHB, SDHC, SDHD, or VHL through Geisinger's MyCode Community Health Initiative between June 2016 and October 2019. Electronic health records (EHRs) of participants were evaluated for a report of pre-disclosure personal and self-reported family histories and post-disclosure risk management and diagnoses.

RESULTS

P/LP variants in genes of interest were identified in 199 of 130,490 (1 in 656) adult Geisinger MyCode patient-participants, 80 of which were disclosed during the study period. Eighty-one percent (n = 65) did not have prior evidence of the result in their EHR and, because they were identified via MyCode, were included in further analyses. Five participants identified via MyCode (8%) had a personal history of syndrome-related features; 16 (25%) had a positive self-reported family history. Time from result disclosure to EHR review was a median of 0.7 years. Post-disclosure, 36 (55.4%) completed a recommended risk management behavior; 11 (17%) were diagnosed with a syndrome-related neoplasm after completing a risk management intervention.

CONCLUSIONS

Broader screening for pathogenic/likely pathogenic variants associated with endocrine tumor syndromes enables detection of at-risk individuals, leads to the uptake of risk management, and facilitates relevant diagnoses. Further research will be necessary to continue to determine the clinical utility of screening diverse, unselected populations for such variants.

Bilateral Pheochromocytoma with Germline MAX Variant without Family History

Recently, the genetic background of pheochromocytomas/paragangliomas (PPGLs) has been rapidly revealed. These tumors have been referred to as the “ten percent tumor”; however, the frequency of genetic variants of PPGLs has turned out to be more common than expected. PPGLs are potentially hereditary tumors and appear clinically sporadic. Here, we report a case of bilateral pheochromocytoma (PCC) with a variant in the MYC-associated factor X (MAX) gene (c.295 + 1G > A). A male patient was diagnosed with adrenal pheochromocytoma (PCC) and underwent a left adrenalectomy at the age of 40. A new tumor in the right adrenal gland was detected at the age of 43. Urinary metanephrine and normetanephrine concentrations gradually increased. The size of the right adrenal PCC continued to increase one year after detection. Genetic testing of the peripheral blood revealed the presence of a pathogenic variant in MAX. The natural history of adrenal PCCs with the MAX variant has not yet been clarified, because the number of reported cases is not sufficient. Thus, clinicians should consider a MAX variant when they find bilateral or multiple PCCs.

Genetic Alterations in Mitochondrial DNA Are Complementary to Nuclear DNA Mutations in Pheochromocytomas

Simple Summary

Mitochondrial DNA (mtDNA) alterations have been reported to play important roles in cancer development and metastasis. However, there is scarce information about pheochromocytomas and paragangliomas (PCCs/PGLs) formation. To determine the potential roles of mtDNA alterations in PCCs/PGLs, we analyzed a panel of 26 nuclear susceptibility genes and the entire mtDNA sequence of 77 human tumors, using NGS. We also performed an analysis of copy-number alterations, large mtDNA deletion, and gene/protein expression. Our results revealed that 53.2% of the tumors harbor a mutation in the susceptibility genes and 16.9% harbor complementary mitochondrial mutations. Large deletions and depletion of mtDNA were found in 26% and 87% of tumors, respectively, accompanied by a reduced expression of the mitochondrial biogenesis markers (PCG1α, NRF1, and TFAM). Furthermore, P62 and LC3a gene expression suggested increased mitophagy, which is linked to mitochondrial dysfunction. These finding suggest a complementarity and a potential contributing role in PCCs/PGLs tumorigenesis.

Abstract

Background: Somatic mutations, copy-number variations, and genome instability of mitochondrial DNA (mtDNA) have been reported in different types of cancers and are suggested to play important roles in cancer development and metastasis. However, there is scarce information about pheochromocytomas and paragangliomas (PCCs/PGLs) formation. Material: To determine the potential roles of mtDNA alterations in sporadic PCCs/PGLs, we analyzed a panel of 26 nuclear susceptibility genes and the entire mtDNA sequence of seventy-seven human tumors, using next-generation sequencing, and compared the results with normal adrenal medulla tissues. We also performed an analysis of copy-number alterations, large mtDNA deletion, and gene and protein expression. Results: Our results revealed that 53.2% of the tumors harbor a mutation in at least one of the targeted susceptibility genes, and 16.9% harbor complementary mitochondrial mutations. More than 50% of the mitochondrial mutations were novel and predicted pathogenic, affecting mitochondrial oxidative phosphorylation. Large deletions were found in 26% of tumors, and depletion of mtDNA occurred in more than 87% of PCCs/PGLs. The reduction of the mitochondrial number was accompanied by a reduced expression of the regulators that promote mitochondrial biogenesis (PCG1α, NRF1, and TFAM). Further, P62 and LC3a gene expression suggested increased mitophagy, which is linked to mitochondrial dysfunction. Conclusion: The pathogenic role of these finding remains to be shown, but we suggest a complementarity and a potential contributing role in PCCs/PGLs tumorigenesis.

A long noncoding RNA-microRNA expression signature predicts metastatic signature in pheochromocytomas and paragangliomas

PURPOSE

In hopes of discovering new markers for metastatic or aggressive phenotypes of pheochromocytomas and paragangliomas (PCPG), we analyzed the noncoding transcriptome from patient gene expression data in The Cancer Genome Atlas.

METHODS

Differential expression of miRNAs was observed between PCPG molecular subtypes. We specifically characterized candidate miRNAs that are upregulated in pseudohypoxic PCPGs with mutations in succinate dehydrogenase complex subunits, B and/or D (SDHB and/or SDHD, respectively), which are mutations associated with unfavorable clinical outcomes.

RESULTS

Our computational analysis identified four candidate miRNAs that showed elevated expression in metastatic compared to non-metastatic PCPGs: miR-182, miR-183, miR-96, and miR-383. We also found six candidate lncRNAs harboring opposite expression patterns from the miRNAs when we analyzed the expression profiles of their predicted target lncRNAs. Three of these lncRNA candidates, USP3-AS1, LINC00877, and AC009312.1, were validated to have reduced expression in metastatic compared to non-metastatic PCPGs. Finally, using univariate and multivariate analysis, we found miRNA miR-182 to be an independent predictor of metastasis-free survival in PCPGs.

CONCLUSIONS

We identified candidate miRNA and lncRNAs associated with metastasis-free survival in PCPGs.

An open-label, crossover study to compare different formulations and evaluate effect of food on pharmacokinetics of pimitespib in patients with advanced solid tumors

This study compared the bioavailability of two pimitespib formulations (Formulations A and B), evaluated the food effect on Formulation A, and evaluated the safety and efficacy of multiple pimitespib doses in patients with solid tumors. This clinical, pharmacological multicenter study had two cohorts and periods. A single dose of Formulation A or B was administered in a crossover design to compare the pharmacokinetics in Cohort 1. In Cohort 2, the effects of fed vs fasting conditions were evaluated among those receiving Formulation A. Subsequently, multiple Formulation A doses were administered to all patients for safety and efficacy assessments. In Cohorts 1 and 2, 12 and 16 patients, respectively, were analyzed for pharmacokinetics. Thirty patients were analyzed for safety and efficacy. Maximum concentration (C_max), area under the curve (AUC)_last, and AUC_inf geometric mean ratios for Formulations A and B (90% confidence interval [CI]) were 0.8078 (0.6569-0.9933), 0.7973 (0.6672-0.9529), and 0.8094 (0.6697-0.9782), respectively; 90% CIs were not within the bioequivalence range (0.80-1.25). In Cohort 2, mean C_max, AUC_last, and AUC_inf were higher in fed vs fasting conditions. No safety concerns emerged with single or multiple administration. Overall response rate, disease control rate, and median progression-free survival were 0%, 33%, and 1.5 months, respectively. Four patients had stable disease ≥ 5 months. Bioequivalence of the two formulations was unconfirmed. Systemic exposure of Formulation A was approximately 20% less than Formulation B. A high-fat/calorie meal increased the relative pharmacokinetics and bioavailability of a single 160-mg dose. Trial Registration: JapicCTI-184191 (Japan Pharmaceutical Information Center) registered on November 5, 2018.

Value of Immunohistochemical Expression of Apelin, Succinate Dehydrogenase B, Chromogranin B, Human Epidermal Growth Factor Receptor-2, Contactin 4, and Succinyl-CoA Synthetase Subunit Beta in Differentiating Metastatic From Non-Metastatic Pheochromocytoma and Paraganglioma

OBJECTIVE

We aimed to retrospectively collect pathologically identified pheochromocytoma and paraganglioma (PPGL) tumor tissues from our center and investigate the expression of apelin and succinyl-CoA synthetase subunit beta (SUCLG2), human epidermal growth factor receptor-2 (HER2 or ERBB-2), contactin 4 (CNTN4), chromogranin B (CHGB), and succinate dehydrogenase B (SDHB) in metastatic and non-metastatic PPGLs, for exploring their roles in the diagnosis of metastatic PPGLs.

METHODS

A total of 369 patients with pathologically and surgically confirmed PPGLs at Xiangya Hospital, Central South University, between June 2010 and June 2020 were retrospectively included. Sixty patients-12 patients with metastatic PPGLs and 48 patients with non-metastatic PPGLs-were selected through propensity score matching (1:4) to reduce the effect of PPGL type, sex, and age. We observed and quantified the expression of apelin, SDHB, CHGB, ERBB-2, CNTN4, and SUCLG2 in paraffin-embedded samples using immunohistochemical staining.

RESULTS

No significant differences were observed between the metastatic group and non-metastatic group with respect to the expression of CNTN4 and SUCLG2. The expression of apelin, SDHB, CHGB, and ERBB-2 was significantly different between the two groups. The expression of apelin, SDHB, and CHGB was significantly lower in the metastatic group than that in the non-metastatic group (P < 0.001). ERBB-2 expression was significantly higher in the metastatic group than in the non-metastatic group (P = 0.042). Kaplan-Meier analysis revealed that patients with negative expression of apelin, SDHB, and CHGB showed significantly lower metastasis-free survival than those with positive expression. Multivariate Cox analysis revealed that SDHB and CHGB levels were independently associated with metastasis-free survival.

CONCLUSION

The expression levels of apelin, CHGB, SDHB, and ERBB-2 may be predictive biomarkers for the diagnosis of metastatic PPGLs. Patients with negative expression of apelin, CHGB, and SDHB should be subjected to frequent postoperative follow-up procedures.

Hypoxia signaling pathway: A central mediator in endocrine tumors

Adequate oxygen levels are essential for the functioning and maintenance of biological processes in virtually every cell, albeit based on specific need. Thus, any change in oxygen pressure leads to modulated activation of the hypoxia pathway, which affects numerous physiological and pathological processes, including hematopoiesis, inflammation, and tumor development. The Hypoxia Inducible Factors (HIFs) are essential transcription factors and the driving force of the hypoxia pathway; whereas, their inhibitors, HIF prolyl hydroxylase domain (PHDs) proteins are the true oxygen sensors that critically regulate this response. Recently, we and others have described the central role of the PHD/HIF axis in various compartments of the adrenal gland and its potential influence in associated tumors, including pheochromocytomas and paragangliomas. Here, we provide an overview of the most recent findings on the hypoxia signaling pathway in vivo, including its role in the endocrine system, especially in adrenal tumors.

Common Diagnostic Challenges and Pitfalls in Genitourinary Organs, With Emphasis on Immunohistochemical and Molecular Updates

CONTEXT.—

Lesions in the genitourinary (GU) organs, both benign and malignant, can demonstrate overlapping morphology, and practicing surgical pathologists should be aware of these potential pitfalls and consider a broad differential diagnosis for each specific type of lesion involving the GU organs. The following summary of the contents presented at the 6th Annual Chinese American Pathologists Association (CAPA) Diagnostic Course (October 10-11, 2020), supplemented with relevant literature review, exemplifies the common diagnostic challenges and pitfalls for mass lesions of the GU system of adults, including adrenal gland, with emphasis on immunohistochemical and molecular updates when relevant.

OBJECTIVE.—

To describe the common mass lesions in the GU system of adults, including adrenal gland, with emphasis on the diagnostic challenges and pitfalls that may arise in the pathologic assessment, and to highlight immunohistochemical workups and emerging molecular findings when relevant.

DATA SOURCES.—

The contents presented at the course and literature search comprise our data sources.

CONCLUSIONS.—

The diagnostic challenges and pitfalls that arise in the pathologic assessment of the mass lesions in the GU system of adults, including adrenal gland, are common. We summarize the contents presented at the course, supplemented with relevant literature review, and hope to provide a diagnostic framework to evaluate these lesions in routine clinical practice.

Management of a Left Lateral Aortic Paraganglioma During Pregnancy: A Rare Case Report

Paragangliomas are rare neuroendocrine tumors mostly diagnosed in young adults. Their association with pregnancy is even rarer, and their impact is even more serious in the absence of adequate management, which may vitally involve maternal and fetal prognosis. In this report, we present a rare case of a left lateral aortic paraganglioma in a pregnant woman in her third trimester during her 31 weeks of gestation, who consulted for a hypertensive peak; the methoxylated derivatives were positive. An abdominal MRI showed a left lateral aortic mass, suggesting a paraganglioma. After a multidisciplinary discussion, the patient underwent laparoscopic surgical resection of the mass after preoperative medical preparation. Pathological examination confirmed the diagnosis of paraganglioma. The overall stay was six days without any short-term complications, including anything related to fetal viability, with a vaginal delivery at 37 weeks of amenorrhea. The patient was followed up for six months with no complications. We highlight the importance of preoperative medical preparation followed by surgical resection in the framework of a multidisciplinary consultation for an improved maternal-fetal prognosis.

Young woman diagnosed with paraganglioma in primary care

A 15-year-old young woman was referred to the emergency room for admission by her general practitioner after receiving the results of urinary metanephrines and catecholamines requested to study the tachycardia, sweating and headaches that she had been presenting progressively last year. Imaging tests showed a large right supraumbilical para-aortic paraganglioma that was successfully removed with surgery after previous medical preparation with adrenergic blockers. Genetic testing showed a heterozygous mutation of the gene succinate dehydrogenase-B. The classic triad of symptoms in these disorders consists of headaches, sweating and tachycardia, usually accompanied by hypertension. We wanted to present this case, a challenging diagnosis of paraganglioma in primary care.

A Critical Appraisal of Contemporary and Novel Biomarkers in Pheochromocytomas and Adrenocortical Tumors

Simple Summary

Pheochromocytomas/paragangliomas (PPGLs) and adrenocortical tumors are neoplasms that originate from different regions of the adrenal gland and display significant heterogeneity with respect to their biological and clinical behavior. They may be sporadic or develop in the context of hereditary syndromes. Adrenocortical tumors are mostly benign but less than 2% are carcinomas associated with a poor outcome when diagnosed in advanced disease. The majority of PPGLS are benign, but a subset may develop metastatic disease. In particular, for PPGLs, it is mandatory to identify biomarkers of high sensitivity and specificity that lead to accurate diagnosis and predict patients with a malignant potential that would benefit from aggressive surveillance and administration of early treatment. Current biomarkers include mostly histopathological and genetic parameters but none of them can be considered independent predictive factors. Recent genomic studies have implemented new molecular biomarkers of high accuracy for the diagnosis and management of PPGLs and adrenocortical tumors. In this review, we summarize the current and novel biomarkers that may be considered valuable tools for diagnosis and prediction of malignancy in patients with PPGLs and adrenocortical tumors.

Abstract

Pheochromocytomas/Paragangliomas (PPGLs) and adrenocortical tumors are rare neoplasms with significant heterogeneity in their biologic and clinical behavior. Current diagnostic and predictive biomarkers include hormone secretion, as well as histopathological and genetic features. PPGL diagnosis is based on biochemical measurement of catecholamines/metanephrines, while histopathological scoring systems have been proposed to predict the risk of malignancy. Adrenocortical tumors are mostly benign, but some can be malignant. Currently, the stage of disease at diagnosis and tumor grade, appear to be the most powerful prognostic factors. However, recent genomic and proteomic studies have identified new genetic and circulating biomarkers, including genes, immunohistochemical markers and micro-RNAs that display high specificity and sensitivity as diagnostic or prognostic tools. In addition, new molecular classifications have been proposed that divide adrenal tumors in distinct subgroups with different clinical outcomes.

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.

Metastatic Malignant Paraganglioma Presenting as a Neck Mass Treated with Radiolabeled Somatostatin Analog

Paragangliomas are rare neuroendocrine tumors that arise from chromaffin-containing tissue. Surgical resection and/or radiation are used for locoregional disease, and reduction of tumor burden with systemic therapy is reserved for metastatic disease. Iobenguane I-131, somatostatin analog (octreotide), and Sunitinib are noncytotoxic options for treatment, while cyclophosphamide, vincristine, and dacarbazine (CVD) and temozolomide are often used as initial chemotherapy options as studies have shown that they offer some tumor response. However, there are no randomized clinical trials demonstrating prolonged survival with the use of chemotherapeutics in metastatic cases. Investigation of alternative therapies that provide survival benefit is thus necessary. We present a case of a 69-year-old female with metastatic malignant paraganglioma presenting as a left parapharyngeal neck mass, which metastasized after surgery, requiring radiation therapy for bony metastasis who was treated with a radioisotope somatostatin analog for disease progression.

GIPC2 is an endocrine-specific tumor suppressor gene for both sporadic and hereditary tumors of RET- and SDHB-, but not VHL-associated clusters of pheochromocytoma/paraganglioma

Pheochromocytoma/paraganglioma (PPGL) is an endocrine tumor of the chromaffin cells in the adrenal medulla or the paraganglia. Currently, about 70% of PPGLs can be explained by germline or somatic mutations in several broadly expressed susceptibility genes including RET, VHL, and SDHB, while for the remaining, mainly sporadic cases, the pathogenesis is still unclear. Even for known susceptible genes, how mutations in these mostly ubiquitous genes result in tissue-specific pathogenesis remains unanswered, and why RET-mutated tumors almost always occur in the adrenal while SDHB-mutated tumors mostly occur extra-adrenal remains a mystery. By analyzing 22 sporadic PPGLs using SNP 6.0 genotyping arrays combined with expression profiling of 4 normal and 4 tumor tissues, we identified GIPC2, a gene located at 1p31.1 with preferential expression in adrenal and inducible by adrenal glucocorticoid, as a novel putative tumor suppressor gene for PPGLs. Copy number deletion and GIPC2 promoter hypermethylation but not GIPC2 mutation, accompanied with reduced GIPC2 expression, were observed in 39 of 55 PPGLs in our cohort. Examination of a published expression database consisting of 188 PPGLs found little GIPC2 expression in Cluster 1A (SDHx-associated) and Cluster 2A (NF1/RET-associated) tumors, but less pronounced reduction of GIPC2 expression in Cluster 1B (VHL-associated) and Cluster 2B/2C tumors. GIPC2 induced p27, suppressed MAPK/ERK and HIF-1ɑ pathways as well as cancer cell proliferation. Overexpressing GIPC2 in PC12 cells inhibited tumor growth in nude mice. We found GIPC2 interacted with the nucleoprotein NONO and both proteins regulated p27 transcription through the same GGCC box on p27 promoter. Significantly, low expression of both GIPC2 and p27 was associated with shorter disease-free survival time of PPGLs patients in the TCGA database. We found that PPGL-causing mutations in RET and in SDHB could lead to primary rat adrenal chromaffin cell proliferation, ERK activation, and p27 downregulation, all requiring downregulating GIPC2. Notably, the RET-mutant effect required the presence of dexamethasone while the SDHB-mutant effect required its absence, providing a plausible explanation for the tumor location preference. In contrast, the PPGL-predisposing VHL mutations had no effect on proliferation and GIPC2 expression but caused p53 downregulation and reduced apoptosis in chromaffin cells compared with wild-type VHL. Thus, our study raises the importance of cortical hormone in PPGL development, and GIPC2 as a novel tumor suppressor provides a unified molecular mechanism for the tumorigenesis of both sporadic and hereditary tumors of Clusters 1A and 2A concerning SDHB and RET, but not tumors of Cluster 1B concerning VHL and other clusters.

Rare Diseases of the Middle Ear and Lateral Skull Base

Otalgia, otorrhea and hearing loss are the most common ear-related symptoms that lead to the consultation of an otolaryngologist. Furthermore, balance disorders and affections of the cranial nerve function may play a role in the consultation. In large academic centres, but also in primary care, the identification of rare diseases of the middle ear and the lateral skull base is essential, as these diseases often require interdisciplinary approaches to establish the correct diagnosis and to initiate safe and adequate treatments. This review provides an overview of rare bone, neoplastic, haematological, autoimmunological and infectious disorders as well as malformations that may manifest in the middle ear and the lateral skull base. Knowledge of rare disorders is an essential factor ensuring the quality of patient care, in particular surgical procedures. Notably, in untypical, complicated, and prolonged disease courses, rare differential diagnoses need to be considered.

Helping young children understand inherited cancer predisposition syndromes using bibliotherapy

Communication with children about hereditary conditions in the family can be difficult for parents. Yet, good communication strategies are leading determinants of adaptation and resilience. With inherited cancer predisposition syndromes that can affect young children such as Li-Fraumeni syndrome (LFS) and hereditary pheochromocytoma and paraganglioma syndrome (HPPS), genetic testing and subsequent surveillance in at-risk children is the optimal intervention. Given testing often commences early, providing children and their parents with appropriate genetic counseling and communication strategies is important for informed decision making. To inform such communication strategies, we used a bibliotherapeutic framework, where stories are delivered prescriptively (i.e., 'bibliotherapy'), to develop a psycho-educational resource for children aged 5-10 years old at risk of either LFS or HPPS. Illustrated storybooks for children were created based on models of developmental comprehension. To ascertain their experience, parents were invited to read a storybook to their child/ren and participate in semi-structured qualitative interviews. Transcripts were analyzed thematically using a general inductive approach. The bibliotherapeutic resource reportedly supported parents with communication about these issues without raising emotional distress in either themselves or their children. The key stages of a bibliotherapeutic interaction were facilitated by the use of this resource, and all parents reported that it would have been useful when their children were first tested and/or diagnosed. This study lays the foundation for the application of bibliotherapy as a psycho-educational intervention in genetic counseling and demonstrates that bibliotherapy may improve the process of communication between parents and children regarding pediatric-inherited cancer syndromes.

Screening of a Large Cohort of Asymptomatic SDHx Mutation Carriers in Routine Practice

CONTEXT

When an SDHx mutation is identified in a patient with a pheochromocytoma (PCC) or a paraganglioma (PGL), predictive genetic testing can detect mutation carriers that would benefit from screening protocols.

OBJECTIVE

To define the tumor detection rate in a large cohort of asymptomatic SDHX mutation carriers.

DESIGN AND SETTING

Retrospective multicentric study in 6 referral centers.

PATIENTS

Between 2005 and 2019, 249 asymptomatic SDHx (171 SDHB, 31 SDHC, 47 SDHD) mutation carriers, with at least 1 imaging work-up were enrolled.

RESULTS

Initial work-up, including anatomical (98% of subjects [97-100% according to center]) and/or functional imaging (67% [14-90%]) detected 48 tumors in 40 patients. After a negative initial work-up, 124 patients benefited from 1 to 9 subsequent follow-up assessments (mean: 1.9 per patient), with a median follow-up time of 5 (1-13) years. Anatomical (86% [49-100 %]) and/or functional imaging (36% [7-60 %]) identified 10 new tumors (mean size: 16 mm [4-50]) in 10 patients. Altogether, 58 tumors (55 paraganglioma [PGL], including 45 head and neck PGL, 2 pheochromocytoma [PCC], 1 gastrointestinal stromal tumor [GIST]), were detected in 50 patients (22 [13%] SDHB, 1 [3.2%] SDHC, and 27 [57%] SDHD), with a median age of 41 years old [11-86], 76% without catecholamine secretion and 80% during initial imaging work-up.

CONCLUSIONS

Imaging screening enabled detection of tumors in 20% of asymptomatic SDHx mutation carriers, with a higher detection rate in SDHD (57%) than in SDHB (13%) and SDHC (3%) mutation carriers, arguing for a gene-by-gene approach. Prospective studies using well-defined protocols are needed to obtain strong and useful data.

What Have We Learned from Molecular Biology of Paragangliomas and Pheochromocytomas?

Recent advances in molecular genetics and genomics have led to increased understanding of the aetiopathogenesis of pheochromocytomas and paragangliomas (PPGLs). Thus, pan-genomic studies now provide a comprehensive integrated genomic analysis of PPGLs into distinct molecularly defined subtypes concordant with tumour genotypes. In addition, new embryological discoveries have refined the concept of how normal paraganglia develop, potentially establishing a developmental basis for genotype-phenotype correlations for PPGLs. The challenge for modern pathology is to translate these scientific discoveries into routine practice, which will be based largely on histopathology for the foreseeable future. Here, we review recent progress concerning the cell of origin and molecular pathogenesis of PPGLs, including pathogenetic mechanisms, genetic susceptibility and molecular classification. The current roles and tools of pathologists are considered from a histopathological perspective, including differential diagnoses, genotype-phenotype correlations and the use of immunohistochemistry in identifying hereditary predisposition and validating genetic variants of unknown significance. Current and potential molecular prognosticators are also presented with the hope that predictive molecular biomarkers will be integrated into risk stratification scoring systems to assess the metastatic potential of these intriguing neoplasms and identify potential drug targets.

Longest survival by the combination of radiation-therapy and resection in patient with metastatic spinal paragangliomas from primary-neck lesion with succinate dehydrogenase subunit B (SDHB) mutation

Metastatic paraganglioma (MPG) of the spine is a rare condition, with no established management. Herein, we report the longest survival case of a primary neck tumor that caused spinal MPG with a succinate dehydrogenase subunit B (SDHB) mutation (c.470delT, p.L157X) which could have promoted its malignancy. This male patient initially presented with a left neck PG which was diagnosed by a biopsy when he was 54 years-old. Simultaneously performed additional examinations revealed the spinal metastatic tumors on the T5-7 vertebrae and L3 vertebra-sacrum. These primary neck and metastatic spinal tumors' growths were once suppressed under the radiation therapy. Nineteen years later, he developed acute progressive paraparesis due to a mass located at the T2-3 level, tightly compressing the spinal cord, and protruding into the left thoracic cavity. We resected the maximum possible area of tumor in the spinal canal, confirmed MPG by histological examination, and then, we administered radiation therapy of 40 Gy in 20 fractions. Eventually, the patient was able to walk unaided with no evidential tumor recurrence for 3 years after treatment. Generally, clinical feature of MPG with SDHB mutation from abdominal lesion is thought to be poor prognosis. However, our case suggests the possibility of long-term control of spinal MPG with the adequate combination of radiation therapy and resection if metastatic lesions from primary-neck lesion with an SDHB mutation are remained to spine.

Metastatic Paraganglioma of the Spine With SDHB Mutation: Case Report and Review of the Literature

BACKGROUND

Paragangliomas (PGLs) are rare neuroendocrine tumors that can arise from any autonomic ganglion of the body. Most PGLs do not metastasize. Here, we present a rare case of metastatic PGL of the spine in a patient with a germline pathogenic succinate dehydrogenase subunit B (SDHB) mutation.

METHODS

In addition to a case report we provide a literature review of metastatic spinal PGL to highlight the importance of genetic testing and long-term surveillance of these patients.

RESULTS

A 45-year-old woman with history of spinal nerve root PGL, 17 years prior, presented with back pain of several months' duration. Imaging revealed multilevel lytic lesions throughout the cervical, thoracic, and lumbar spine as well as involvement of the right mandibular condyle and clavicle. Percutaneous biopsy of the L1 spinal lesion confirmed metastatic PGL and the patient underwent posterior tumor resection and instrumented fusion of T7-T11. Postoperatively the patient was found to have a pathogenic SDHB deletion.

CONCLUSIONS

Patients with SDHx mutation, particularly SDHB, have increased risk of developing metastatic PGLs. Consequently, these individuals require long-term surveillance given the risk for developing new tumors or disease recurrence, even years to decades after primary tumor resection. Surgical management of spinal metastatic PGL involves correcting spinal instability, minimizing tumor burden, and alleviating epidural cord compression. In patients with metastatic PGL of the spine, genetic testing should be considered.

Functional Malignant Retroperitoneal Paraganglioma with Liver Metastasis: a Rare Case Report

Paragangliomas are rare neoplasms. Their specific annual incidence is still unclear. These are rare neuroendocrine tumors which arise from extra-adrenal paraganglioma and they have the ability to secrete catecholamines. Most of them are diagnosed in the 3rd to 5th decades of life with mean age around 47 years. Majority of them are benign; however, malignant tumors with metastatic behavior are very rare. The incidence of malignant paraganglioma is estimated around 93/400 million people. The clinical course of metastatic malignant disease is variable and the reported 5-year survival is around 12-84%. There is no curative treatment option for malignant metastatic paraganglioma. If resectable, both, primary and metastasis should be resected. The only criteria which defines its malignancy is the presence of metastatic spread of chromaffin cells in tissues that normally do not contain such cells. Functional paraganglioma secretes excessive catecholamines which clinically manifest as paroxysmal hypertension, headache, sweating, and palpitations. We reported a case of young male who presented with huge left retroperitoneal mass and after evaluation found to have a functional malignant paraganglioma with liver metastasis. Surgical resection of the primary malignant paraganglioma with metastatectomy helps in decreasing the complications, improving the symptoms and prolonging the survival.

Genetic Analysis and Clinical Characteristics of Hereditary Pheochromocytoma and Paraganglioma Syndrome in Korean Population

BACKGROUND

Pheochromocytoma and paragangliomas (PPGL) are hereditary in approximately 30% to 40% cases. With the advancement of genetic analysis techniques, including next-generation sequencing (NGS), there were attempts to classify PPGL into molecular clusters. With NGS being applied to clinical settings recently, we aimed to review the results of genetic analysis, including NGS, and investigate the association with clinical characteristics in Korean PPGL patients.

METHODS

We reviewed the medical records of PPGL patients who visited Severance hospital from 2006 to 2019. We documented the clinical phenotype of those who underwent targeted NGS or had known germline mutations of related genes.

RESULTS

Among 57 PPGL patients, we found 28 pathogenic germline mutations of susceptibility genes. Before the targeted NGS was implemented, only obvious syndromic feature lead to the Sanger sequencing for the specific genes. Therefore, for the exact prevalence, only patients after the year 2017, when targeted NGS was added, were included (n=43). The positive germline mutations were found in 14 patients; thus, the incidence rate is 32.6%. Patients with germline mutations had a higher likelihood of family history. There were significant differences in the type of PPGLs, percentage of family history, metastasis rate, presence of other tumors, and biochemical profile among three molecular clusters: pseudohypoxic tricarboxylic acid cycle-related, pseudohypoxic von Hippel-Lindau (VHL)/endothelial PAS domain-containing protein 1-related, and kinase-signaling group. Germline mutations were identified in seven PPGL-related genes (SDHB, RET, VHL, NF1, MAX, SDHA, and SDHD).

CONCLUSION

We report the expected prevalence of germline mutations in Korean PPGL patients. NGS is a useful and accessible tool for genetic analysis in patients with PPGLs, and further research on molecular classification is needed for precise management.

Neuroendocrine tumour with Tetralogy of Fallot: a case report

Paragangliomas occurring with cyanotic heart disease is a known association. We present a case of an active paraganglioma in a child with unoperated Tetralogy of Fallot, which posed a management challenge considering the pathophysiology of both these conditions.