Hereditary Pheochromocytoma

Adrenal pheochromocytoma: is it all or the tip of the iceberg?

Adrenal pheochromocytoma is not always a simple retroperitoneal tumor but may be part of a more complicated condition. It often has a spectrum of complex and variable imaging features, may present as a collision tumor and composite tumor, and is associated with a variety of clinical syndromes. A comprehensive understanding of the clinical, pathological, and variable imaging manifestations of pheochromocytoma can help radiologists make an accurate diagnosis. This article reviews various special imaging features of pheochromocytoma and pheochromocytoma-related diseases.

Surgical Remission of Diabetes in a Patient With Mutation of RET Proto-Oncogene

OBJECTIVE

In pheochromocytomas, accelerated catecholamine production can cause secondary diabetes. The gene responsible for multiple endocrine neoplasia type 2 (MEN2)-related pheochromocytomas is the RET proto-oncogene. The objective of this report is to describe a unique case of surgical remission of misdiagnosed type 2 diabetes mellitus (T2DM) in a woman with bilateral pheochromocytoma and RET proto-oncogene mutation.

METHODS

Clinical examination, urinary metanephrine level, triple-phase abdominal computed tomography (CT) with adrenal protocol, positron emission tomography with ¹⁸F-fluorodeoxyglucose integrated with CT, surgical pathology, and genetic testing were performed.

RESULTS

A 46-year-old woman with a 5-year history of apparent T2DM complicated by neuropathy, without a contributory family history, presented with occasional headaches, weight loss, and abdominal pain. A 24-hour urinary metanephrine of 5 mg (reference range, 0.05-1 mg) was found. Abdominal CT showed bilateral adrenal masses with <60% washout. Positron emission tomography with ¹⁸F-fluorodeoxyglucose integrated with CT showed a left solid-cystic lesion with low metabolic activity and a right nodular lesion with a higher metabolic activity, which was conclusive of bilateral pheochromocytoma. The remission of diabetes was achieved 1 year after a bilateral adrenalectomy. In addition, a multinodular goiter was found, and a fine-needle aspiration biopsy confirmed that it was a medullary thyroid carcinoma. A heterozygous pathogenic variant of the RET proto-oncogene was found and MEN2A was confirmed.

CONCLUSION

This is the first report of a patient with a RET proto-oncogene mutation experiencing remission of diabetes after surgical resection of bilateral pheochromocytomas. Timely recognition and treatment of the underlying condition are important to potentially achieve diabetes remission and prevent its long-term complications.

An Unusual Histology for a Lung Nodule: A Case Report of Primary Pulmonary Paraganglioma

Introduction: Primary pulmonary paraganglioma is a rare tumor with few cases reported in literature and unspecific clinical presentation.

Case Presentation: A 49-year-old woman presented to our department with an incidental finding of a pulmonary mass at chest X-ray and no associated clinical symptom. The CT scan and the FDG-PET showed mild uptake of contrast, but a definitive diagnosis was only possible after surgery through histopathological examination.

Conclusion: Paragangliomas originating in the pulmonary tissue are generally non-functioning masses discovered incidentally in otherwise asymptomatic patients. Surgery appears to be the best treatment option, with only radiologic follow-up necessary afterwards.

Screening for Hereditary Pheochromocytoma in a Patient with Neurofibromatosis Type 1: A Case Report

Pheochromocytoma (PHEO) is a rare tumour that arises from adreno-medullary chromaffin cells and secretes catecholamines. These hormones are also secreted by paragangliomas, which derive from extra-adrenal cells of the sympathetic paravertebral ganglia. At least one-third of PHEOs are familial. Neurofibromatosis type 1 (NF1), or von Recklinghausen's disease, is diagnosed upon clinical criteria, and the study of PHEO is advised if hypertension is present. The incidence of PHEO in NF1 is 0.1-5.7% and explains hypertension in 20-50% of these patients. Recent advances in the treatment of this condition and preoperative preparation allow us to reduce its high cardiovascular morbimortality. Here we present the case of a 31-year-old female with known NF1 who presented with 5 months' history of non-specific symptoms and an episode of intraoperative hypertensive crisis. The workup detected a left sided PHEO, which was treated surgically. Our case illustrates the high prevalence of hereditary PHEO and how its presentation can go unnoticed. It reinforces the significance of screening for PHEO in patients with NF1.

Screening for Hereditary Pheochromocytoma in a Patient with Neurofibromatosis Type 1: A Case Report

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Recent advances in the management of pheochromocytoma and paraganglioma

Pheochromocytomas and paragangliomas (PPGLs) are rare tumors that cause refractory hypertension and hypertensive crisis. Although metastatic disease accounts for 30% of PPGLs, the diagnosis of malignancy is difficult without the presence of metastatic lesions. Here, we review several advancements in the diagnosis and treatment of PPGL. A nationwide epidemiological survey in Japan revealed that the annual number of patients with PPGL was 3000, which was higher than that reported previously. While plasma and urine fractionated metanephrines are recommended for use in specific biochemical testing for diagnosis, creatinine-corrected fractionated metanephrines in spot urine samples that had been widely used in Japan as a convenient screening test were shown to be as useful as 24-h urine fractionated metanephrines. Regarding imaging studies, a more specific functional imaging for PPGLs, ⁶⁸Ga DOTATATE, was newly developed. ⁶⁸Ga DOTATATE provides a clear image with high sensitivity and specificity. Currently, PASS or GAPP histological scores and SDHB immunostaining are clinically used to attempt to discriminate benign from malignant tumors. However, since this distinguishing process remains difficult, all cases were classified as malignant with the possibility of metastasis in the WHO classification of endocrine tumors updated in 2017. Approximately 60% of PPGLs have germline mutations in PPGL-related genes. Currently, the genes are classified into two clusters based on their mechanism for the etiology of tumorigenesis. Based on the possible mechanisms of tumor development associated with gene mutations, several molecular target drugs are under evaluation to explore more promising treatments for malignant PPGL.

Advanced pharmacological therapies for neurofibromatosis type 1-related tumors

Neurofibromatosis Type 1 (NF1) is an autosomal dominant tumor-predisposition disorder that is caused by a heterozygous loss of function variant in the NF1 gene, which encodes a protein called neurofibromin. The absence of neurofibromin causes increased activity in the Rat sarcoma protein (RAS) signalling pathway, which results in an increased growth and cell proliferation. As a result, both oncological and non-oncological comorbidities contribute to a high morbidity and mortality in these patients. Optic pathways gliomas, plexiform neurofibromas and malignant peripheral nerve sheath tumor (MPNST) are the most frequent NF1-associated tumors. The treatment of these complications is often challenging, since surgery may not be feasible due to the location, size, and infiltrative nature of these tumors, and standard chemotherapy or radiotherapy are burdened by significant toxicity and risk for secondary malignancies. For these reasons, following the novel discoveries of the pathophysiological mechanisms that lead to cell proliferation and tumorigenesis in NF1 patients, emerging drugs targeting specific signalling pathways (i.e. the MEK/ERK cascade), have been developed with promising results.

Abnormal glucose tolerance in a patient with pheochromocytoma and ACTH-independent subclinical Cushing's syndrome involving the same adrenal gland

Coexistence of adrenocorticotropin hormone (ACTH)-independent subclinical Cushing’s syndrome (SCS) with pheochromocytoma involving the same adrenal tumor is rare. Moreover, no previous reports have compared pre- and postoperative insulin sensitivities in these cases. A 74-year-old woman was admitted to our hospital with hyperhidrosis, dry mouth, and weight loss. Pheochromocytoma was suspected based on elevated circulating catecholamines, and was confirmed by scintigraphy and histopathological analysis. Laboratory data, low ACTH, and lack of a diurnal cortisol rhythm indicated coexisting Cushing’s syndrome (CS). The atypical symptoms of CS and lack of cortisol suppression after 1 and 8 mg dexamethasone suppression tests confirmed the diagnosis of SCS. Histopathological analysis demonstrated autonomous cortisol production caused by paracrine stimulation from the pheochromocytoma. Her fasting plasma glucose level on admission was 372 mg/dL and her hemoglobin (Hb) A1c was 11.0%. HbA1c decreased to 5.2% postoperatively, with improved insulin secretion indicated by homeostasis model assessment β (18.1 to 45) and urinary C-peptide (26.5 to 48.5 mg/day). Herein we report a rare case of pheochromocytoma and SCS involving the same adrenal tumor, with the first documented levels of glucose tolerance before and after surgery. Coexisting SCS should thus be considered in patients with pheochromocytoma presenting with severely uncontrolled diabetes mellitus.

Clinical Syndromes and Genetic Screening Strategies of Pheochromocytoma and Paraganglioma

Pheochromocytomas (PCCs) are rare neuroendocrine tumors that originate from chromaffin cells of the adrenal medulla, and paragangliomas (PGLs) are extra-adrenal pheochromocytomas. These can be mainly found in clinical syndromes including multiple endocrine neoplasia (MEN), von Hippel–Lindau (VHL) syndrome, neurofibromatosis-1 (NF-1) and familial paraganglioma (FPGL). PCCs and PGLs are thought to have the highest degree of heritability among human tumors, and it has been estimated that 60% of the patients have genetic abnormalities. This review provides an overview of the clinical syndrome and the genetic screening strategies of PCCs and PGLs. Comprehensive screening principles and strategies, along with specific screening based on clinical symptoms, biochemical tests and immunohistochemistry, are discussed.

Proton therapy for treatment of intracranial benign tumors in adults: A systematic review

INTRODUCTION

The depth-dose distribution of a proton beam, materialized by the Bragg peak makes it an attractive radiation modality as it reduces exposure of healthy tissues to radiations, compared with photon therapy Prominent indications, based on a long-standing experience are: intraocular melanomas, low-grade skull-base and spinal canal malignancies. However, many others potential indications are under investigations such as the benign morbid conditions that are compatible with an extended life-expectancy: low grade meningiomas, paragangliomas, pituitary adenomas, neurinomas craniopharyngioma or recurrent pleomorphic adenomas.

MATERIALS

Given the radiation-induced risk of secondary cancer and the potential neurocognitive and functional alteration with photonic radiotherapy, we systematically analyzed the existing clinical literature about the use of proton therapy as an irradiation modality for cervical or intracranial benign tumors. The aim of this review was to report clinical outcomes of adult patients with benign intracranial or cervical tumors treated with proton therapy and to discuss about potential advantages of proton therapy over intensity modulated radiotherapy or radiosurgery.

RESULTS

Twenty-four studies were included. There was no randomized studies. Most studies dealt with low grade meningiomas (n = 9). Studies concerning neurinoma (n = 4), pituitary adenoma (n = 5), paraganglioma (n = 5), or craniopharyngioma (n = 1) were fewer. Whatever the indication, long term local control was systematically higher than 90% and equivalent to series with conventional radiotherapy.

CONCLUSION

Proton-therapy for treatment of adult benign intracranial and cervical tumors is safe. Randomized or prospective cohorts with long term cognitive evaluations are needed to assess the real place of proton-therapy in the treatment of adults benign head and neck tumors.

Treatment responses to antiangiogenetic therapy and chemotherapy in nonsecreting paraganglioma (PGL4) of urinary bladder with SDHB mutation: A case report

INTRODUCTION

Paraganglioma (PGL) is a rare neuroendocrine tumor. Currently, the malignancy is defined as the presence of metastatic spread at presentation or during follow-up. Several gene mutations are listed in the pathogenesis of PGL, among which succinate dehydrogenase (SDHX), particularly the SDHB isoform, is the main gene involved in malignancy. A 55-year-old male without evidence of catecholamine secretion had surgery for PGL of the urinary bladder. After 1 year, he showed a relapse of disease and demonstrated malignant PGL without evidence of catecholamine secretion with a germline heterozygous mutation of succinate dehydrogenase B (SDHB). After failure of a second surgery for relapse, he started medical treatment with sunitinib daily but discontinued due to serious side effects. Cyclophosphamide, vincristine, and dacarbazine (CVD) chemotherapeutic regimen stopped the disease progression for 7 months.

CONCLUSION

Malignant PGL is a very rare tumor, and SDHB mutations must be always considered in molecular diagnosis because they represent a critical event in the progression of the oncological disease. Currently, there are few therapeutic protocols, and it is often difficult, as this case demonstrates, to decide on a treatment option according to a reasoned set of choices.

A Novel RET D898Y Germline Mutation in a Patient with Pheochromocytoma

Pheochromocytoma and paraganglioma are tumors of neuroectoderm origin. Up to 40% of patients with these tumors have germline mutations in known susceptibility genes. We report a novel RET germline mutation (exon 15; c.2692G>T (D898Y)) in a pheochromocytoma patient, as well as in her two asymptomatic sons and older sister. A 49-year-old female came to our clinic presenting with a right adrenal gland mass detected during a healthcare examination. Her mother and two sisters had previously undergone thyroidectomy for papillary thyroid carcinomas. The levels of vanillylmandelic acid and other catecholamines were elevated in 24-hour urine, and an imaging study revealed a right adrenal mass. She underwent laparoscopic adrenalectomy and the final pathologic diagnosis was pheochromocytoma. Mutation screening detected a RET p.D898Y mutation, both in the patient and in the patient's two sons and older sister. This is the first description of a RET D898Y mutation in a pheochromocytoma patient and her family. The mutation should be categorized as a variant of unknown significance because no RET gene related disorders were detected in this family. Long term follow-up will be required to determine the clinical significance of the RET D898Y mutation.

MicroRNA 183 family profiles in pheochromocytomas are related to clinical parameters and SDHB expression

This study aims to examine the expression profiles of the miR-183 cluster (miR-96/182/183) in pheochromocytoma. Pheochromocytoma tissues were prospectively collected from 50 patients with pheochromocytoma. Expression of miR-183 cluster members and SDHB protein expression were analyzed in these tissues by quantitative real-time polymerase chain reaction and immunohistochemistry, respectively. The expression of miR-183 cluster members in pheochromocytomas was correlated with the clinical and pathological parameters of these patients. The expression levels of miR-183 cluster members were predominantly downregulated or deleted in pheochromocytoma. Low expression or deletion of miR-96 was predominantly noted in younger patients with pheochromocytoma (<50 years, P=.01). Female patients in the study group showed marked deletion of miR-182 (P=.05). Deletion of the cluster was also associated with SDHB protein expression in pheochromocytoma. Moreover, patients with low miR-183 cluster expression had a slightly better survival rate when compared with patients with high expression. To conclude, the findings indicate a role for miR-183 cluster members in the pathogenesis and clinical progression of pheochromocytoma.

Molecular markers of paragangliomas/pheochromocytomas

Paragangliomas/pheochromocytomas comprise rare tumors that arise from the extra-adrenal paraganglia, with an incidence of about 2 to 8 per million people each year. Approximately 40% of cases are due to genetic mutations in at least one out of more than 30 causative genes. About 25-30% of pheochromocytomas/paragangliomas develop under the conditions of a hereditary tumor syndrome a third of which are caused by mutations in the VHL gene. Together, the gene mutations in this disorder have implicated multiple processes including signaling pathways, translation initiation, hypoxia regulation, protein synthesis, differentiation, survival, proliferation, and cell growth. The present review contemplates the mutations associated with the development of pheochromocytomas/paragangliomas and their potential to serve as specific markers of these tumors and their progression. These data will improve our understanding of the pathogenesis of these tumors and likely reveal certain features that may be useful for early diagnostics, malignancy prognostics, and the determination of new targets for disease therapeutics.

Pheochromocytoma and paraganglioma in patients with neurofibromatosis type 1

OBJECTIVE

Individuals with neurofibromatosis type 1 (NF1) are at an increased risk of developing a pheochromocytoma or paraganglioma (PHEO/PGL). However, the best case detection strategy is unknown. Our objectives were to describe the prevalence, clinical presentation and outcomes of PHEO/PGL associated with NF1 and formulate case detection testing recommendations for PHEO/PGL.

DESIGN

A retrospective cohort study from 1959 to 2015, Tertiary medical centre.

PATIENTS AND MEASUREMENTS

We studied 41 patients with NF1 and PHEO/PGL who were identified using the PHEO/PGL and NF1 databases: 3289 and 1415 patients, respectively. Our main outcome measures were prevalence of PHEO/PGL in NF1 and occurrence of bilateral, recurrent, or metastatic disease and method of PHEO/PGL detection (symptoms vs incidental vs biochemical case detection testing).

RESULTS

The prevalence of PHEO/PGL in patients with NF1 was 2·9%. The 41 patients included 23 men (56%) and 18 women. The median age at diagnosis was 41·0 years (range 14-67). The median tumour size was 3·4 cm (range 0·8-9·5). Bilateral PHEO was identified in 17% (n = 7) of patients, all women. Metastatic or recurrent disease occurred in 7·3% (n = 3). In the last 25 years, PHEO/PGL was diagnosed after incidental finding on computed imaging in 31% of patients (n = 11). Only three patients (7·3%) had PHEO/PGL discovered because of biochemical case detection testing.

CONCLUSION

We recommend patients with NF1 have biochemical case detection testing for PHEO/PGL every 3 years starting at age 10 to 14 years. Biochemical case detection testing should also be carried out prior to elective surgical procedures and conception.

Silent genetic alterations identified by targeted next-generation sequencing in pheochromocytoma/paraganglioma: A clinicopathological correlations

AIMS

The goal of this pilot study was to develop a customized, cost-effective amplicon panel (Ampliseq) for target sequencing in a cohort of patients with sporadic phaeochromocytoma/paraganglioma.

METHODS

Phaeochromocytoma/paragangliomas from 25 patients were analysed by targeted next-generation sequencing approach using an Ion Torrent PGM instrument. Primers for 15 target genes (NF1, RET, VHL, SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, MAX, MEN1, KIF1Bβ, EPAS1, CDKN2 & PHD2) were designed using ion ampliseq designer. Ion Reporter software and Ingenuity® Variant Analysis™ software (www.ingenuity.com/variants) from Ingenuity Systems were used to analysis these results.

RESULTS

Overall, 713 variants were identified. The variants identified from the Ion Reporter ranged from 64 to 161 per patient. Single nucleotide variants (SNV) were the most common. Further annotation with the help of Ingenuity variant analysis revealed 29 of these 713variants were deletions. Of these, six variants were non-pathogenic and four were likely to be pathogenic. The remaining 19 variants were of uncertain significance. The most frequently altered gene in the cohort was KIF1B followed by NF1. Novel KIF1B pathogenic variant c.3375+1G>A was identified. The mutation was noted in a patient with clinically confirmed neurofibromatosis. Chromosome 1 showed the presence of maximum number of variants.

CONCLUSIONS

Use of targeted next-generation sequencing is a sensitive method for the detecting genetic changes in patients with phaeochromocytoma/paraganglioma. The precise detection of these genetic changes helps in understanding the pathogenesis of these tumours.

Primary hypercortisolism and phaeochromocytoma next to, but not related to, each other

This is the first report of unilateral hypercortisolism and phaeochromocytoma that cannot be explained by medullary tumourigenic adrenocorticotropic hormone (ACTH) excretion. The patient was referred for an adrenal incidentaloma with hypertension but no Cushingoid features, disturbed glucose tolerance and osteopaenia. Additional testing revealed hypercortisolism with suppressed ACTH, and a right-sided phaeochromocytoma with typical radiographic appearance. Resection of the right adrenal completely normalised the clinical symptoms and biochemistry, and increased ACTH concentrations, implicating initial suppression. Histology revealed a tumour consisting of chromaffin cells, with only pre-existing cortical tissue containing groups of ACTH-positive cells. Recent human studies in primary Cushing's syndrome demonstrated that a paracrine effect of these aberrant cells, assumed to be Leydig cells in origin, results in hypercortisolism by stimulation of surrounding steroidogenic cells, leading to systemic ACTH suppression. We propose that 2 diagnoses within 1 adrenal, being phaeochromocytoma and autonomous cortisol overproduction due to adjoining aberrant ACTH-producing cells, explain the clinical picture.

Somatic and germline mutations in NETs: Implications for their diagnosis and management

It is now understood that specific somatic and germline mutations may lead to the development of the neuroendocrine tumours (NETs). NETs usually occur as sporadic isolated tumours, although they also may present as part of complex familial endocrine cancer syndromes, such as multiple endocrine neoplasia type 1 (MEN1) and type 2 (MEN2), Von Hippel-Lindau (VHL) and neurofibromatosis syndromes, tuberous sclerosis, Carney triad and dyad, Reed syndrome and polycythaemia-paraganglioma syndromes. Only in MEN2 syndrome is there a specific genotype-phenotype correlation, although in both sporadic and syndromic NETs some gene mutations are associated with specific clinico-pathological features and prognosis. There have been several advances in our understanding of the NETs leading to earlier detection and targeted therapeutic treatment, but given the poor prognosis associated with metastatic NETs, it will be necessary to find new biomarkers for the prediction of malignant potential and to find novel therapeutic targets for NETs.

Primary Pulmonary Paraganglioma: A Case Report and Review of Literature

Primary pulmonary paraganglioma is a rare disease. We report a case of a 37-year old female patient with space-occupying lesions in the right lower pulmonary lobe during a routine examination without any symptoms. The patient underwent video-assisted thoracoscopic surgery (VATS) resection of the right middle lobe and dissection of hilar and mediastinal lymph nodes under general anesthesia. She recovered without recrudescence. Preoperative diagnosis is difficult. Accurate diagnosis requires pathological examination, and immunohistochemical test is particularly important. Complete resection is the first treatment option for solitary primary pulmonary paraganglioma; however, VATS is a better technique. Given the high local control rates and few complications of radiotherapy, it is considered as a standard treatment.