Gallbladder Paraganglioma Associated with Mutation: a Potential Pitfall on F-FDOPA PET Imaging.

A 36-year-old male patient initially presented with hypertension, tinnitus, bilateral carotid masses, a right jugular foramen, and a periaortic arch mass with an elevated plasma dopamine level but an otherwise normal biochemical profile. On surveillance MRI 4 years after initial presentation, he was found to have a 2.2-cm T2 hyperintense lesion with arterial enhancement adjacent to the gallbladder, which demonstrated avidity on Ga-DOTATATE PET/CT and retrospectively on F-FDOPA PET/CT but was non-avid on F-FDG PET/CT.

Clinical, Diagnostic, and Treatment Characteristics of -Related Metastatic Pheochromocytoma and Paraganglioma.

Pheochromocytoma and paraganglioma (PHEO/PGL) are rare neuroendocrine tumors which may cause potentially life-threatening complications, with about a third of cases found to harbor specific gene mutations. Thus, early diagnosis, treatment, and meticulous monitoring are of utmost importance. Because of low incidence of succinate dehydrogenase complex subunit A ()-related metastatic PHEO/PGL, currently there exists insufficient clinical information, especially with regards to its diagnostic and treatment characteristics.

18F-FDOPA PET/CT Imaging of MAX-Related Pheochromocytoma.

Context: MYC-associated factor X (MAX) has been recently described as a new susceptibility pheochromocytoma (PHEO) gene with a total of ~40 reported cases. At present, no study has specifically described the functional imaging phenotype of MAX-related PHEO.

Objective, Patients, And Design: The objective of the present study was to present our experience with contrast-enhanced computed tomography (CT) and 18F-fluorodihydroxyphenylalanine (18F-FDOPA) positron emission tomography (PET)/CT in six consecutive patients (four at the initial diagnosis and two at the follow-up evaluation) with rare, but clinically important, MAX-related PHEOs.

Superiority of Ga-DOTATATE over F-FDG and anatomic imaging in the detection of succinate dehydrogenase mutation (SDHx )-related pheochromocytoma and paraganglioma in the pediatric population.

Purpose: To evaluate and compare diagnostic performance of Ga-DOTA(0)-Tyr(3)-octreotate (Ga-DOTATATE) with F-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography-computed tomography (PET/CT) and anatomic imaging using computed tomography and/or magnetic resonance (CT/MR) imaging in detection of SDHx-related pheochromocytomas and paragangliomas (PPGLs) in pediatric patients.

Methods: Nine pediatric patients (5:4, girls:boys; 14.6 ± 2.

SDHB-related pheochromocytoma and paraganglioma penetrance and genotype-phenotype correlations.

Purpose: Succinate dehydrogenase subunit B (SDHB) gene mutations are associated with an aggressive clinical disease course of pheochromocytoma/paraganglioma (PHEO/PGL). Limited information is available concerning PHEO/PGL penetrance among SDHB mutation carriers with regards to primary tumor location, specific mutation type, and gender. We assessed PHEO/PGL penetrance in SDHB mutation carriers and described the clinical presentation and disease course.

Functional Imaging Signature of Patients Presenting with Polycythemia/Paraganglioma Syndromes.

Pheochromocytoma/paraganglioma (PPGL) syndromes associated with polycythemia have previously been described in association with mutations in the von Hippel-Lindau gene. Recently, mutations in the prolyl hydroxylase gene () 1 and 2 and in the hypoxia-inducible factor 2 α () were also found to be associated with multiple and recurrent PPGL. Such patients also presented with PPGL and polycythemia, and later on, some presented with duodenal somatostatinoma.

Novel insights into the polycythemia-paraganglioma-somatostatinoma syndrome.

Worldwide, the syndromes of paraganglioma (PGL), somatostatinoma (SOM) and early childhood polycythemia are described in only a few patients with somatic mutations in the hypoxia-inducible factor 2 alpha (HIF2A). This study provides detailed information about the clinical aspects and course of 7 patients with this syndrome and brings into perspective these experiences with the pertinent literature. Six females and one male presented at a median age of 28 years (range 11-46).

PET/CT comparing (68)Ga-DOTATATE and other radiopharmaceuticals and in comparison with CT/MRI for the localization of sporadic metastatic pheochromocytoma and paraganglioma.

Purpose: Pheochromocytomas/paragangliomas (PPGLs) and their metastases are tumors that predominantly express somatostatin receptor 2 (SSR2). (68)Ga-DOTA(0)-Tyr(3)-octreotate ((68)Ga-DOTATATE) is a PET radiopharmaceutical with both high and selective affinity for SSRs. The purpose of this study was to evaluate the utility of (68)Ga-DOTATATE in comparison with other specific and nonspecific radiopharmaceuticals recommended in the current guidelines for the localization of metastatic sporadic PPGL by PET/CT.

68Ga-DOTATATE PET/CT in the Localization of Head and Neck Paragangliomas Compared with Other Functional Imaging Modalities and CT/MRI.

Unlabelled: Pheochromocytomas/paragangliomas overexpress somatostatin receptors, and recent studies have already shown excellent results in the localization of sympathetic succinate dehydrogenase complex, subunit B, mutation-related metastatic pheochromocytomas/paragangliomas using (68)Ga-DOTATATE PET/CT. Therefore, the goal of our study was to assess the clinical utility of this functional imaging modality in parasympathetic head and neck paragangliomas (HNPGLs) compared with anatomic imaging with CT/MRI and other functional imaging modalities, including (18)F-fluorohydroyphenylalanine ((18)F-FDOPA) PET/CT, currently the gold standard in the functional imaging of HNPGLs.

Methods: (68)Ga-DOTATATE PET/CT was prospectively performed in 20 patients with HNPGLs.

Succinate dehydrogenase gene mutations in cardiac paragangliomas.

Pheochromocytomas and paragangliomas are chromaffin cell tumors arising from neuroendocrine cells. At least 1/3 of paragangliomas are related to germline mutations in 1 of 17 genes. Although these tumors can occur throughout the body, cardiac paragangliomas are very rare, accounting for <0.

Counseling patients with succinate dehydrogenase subunit defects: genetics, preventive guidelines, and dealing with uncertainty.

The discovery that mutations in the succinate dehydrogenase (SDH) complex subunit (SDHA, B/C/D/AF2) genes predispose patients to the development of tumors has led to the identification of a large population of patients and relatives at risk for developing malignancies. The most frequent conditions associated with these mutations are the familial paraganglioma syndromes. Other tumors that are frequently associated with SDH mutations (SDHx) are gastrointestinal stromal tumors and renal cell carcinomas.

Staging and functional characterization of pheochromocytoma and paraganglioma by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography.

Background: Pheochromocytomas and paragangliomas (PPGLs) are rare tumors of the adrenal medulla and extra-adrenal sympathetic chromaffin tissues; their anatomical and functional imaging are critical to guiding treatment decisions. This study aimed to compare the sensitivity and specificity of (18)F-fluorodeoxyglucose positron emission tomography with computed tomography ((18)F-FDG PET/CT) for tumor localization and staging of PPGLs with that of conventional imaging by [(123)I]-metaiodobenzylguanidine single photon emission CT ((123)I-MIBG SPECT), CT, and magnetic resonance imaging (MRI).

Methods: A total of 216 patients (106 men, 110 women, aged 45.

False-negative ¹²³I-MIBG SPECT is most commonly found in SDHB-related pheochromocytoma or paraganglioma with high frequency to develop metastatic disease.

The purpose of this study was to present the characteristics and outcome of patients with proven pheochromocytoma or paraganglioma who had false-negative iodine-123 metaiodobenzylguanidine single photon emission computed tomography ((123)I-MIBG SPECT). Twenty-one patients with false-negative (123)I-MIBG SPECT (7 males, 14 females), aged 13-55 years (mean: 41.40 years), were included.

Comparison of clinical and imaging features in succinate dehydrogenase-positive versus sporadic paragangliomas.

Background: Limited data exist concerning the clinical and imaging features that distinguish sporadic from familial paragangliomas (PGLs).

Methods: Clinical, genetic (succinate dehydrogenase [SDHB] vs no SDHx), and imaging (computed tomography [CT], magnetic resonance imaging, (18)F-fluoro-deoxy-glucose positron emission tomography [(18)F-FDG-PET]) features obtained during a decade in 124 PGL patients were studied. Data were analyzed by Fisher's exact test or Wilcoxon rank-sum test.

Functional imaging of SDHx-related head and neck paragangliomas: comparison of 18F-fluorodihydroxyphenylalanine, 18F-fluorodopamine, 18F-fluoro-2-deoxy-D-glucose PET, 123I-metaiodobenzylguanidine scintigraphy, and 111In-pentetreotide scintigraphy.

Rationale: Accurate diagnosis of head and neck paragangliomas is often complicated by biochemical silence and lack of catecholamine-associated symptoms, making accurate anatomical and functional imaging techniques essential to the diagnostic process.

Methods: Ten patients (seven SDHD, three SDHB), with a total of 26 head and neck paragangliomas, were evaluated with anatomical and functional imaging. This study compares five different functional imaging techniques [(18)F-fluorodihydroxyphenylalanine ((18)F-FDOPA) positron emission tomography (PET), (18)F-fluorodopamine ((18)F-FDA) PET/computed tomography (CT), (18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG) PET/CT, (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy, and (111)In-pentetreotide scintigraphy] in the localization of head and neck paragangliomas.

Exercise-induced nausea and vomiting: another sign and symptom of pheochromocytoma and paraganglioma.

A cohort of nine patients, mostly young adults, presented with a new sign/symptom of pheochromocytoma/paraganglioma: exercise-induced nausea and vomiting. The aims of this article are to introduce this sign/symptom and offer a possible hypothesis for the observation. Following a 2000 report from a paraganglioma patient experiencing exercise-induced nausea and vomiting, we began asking patients about instances of nausea and vomiting with exercise.

Succinate dehydrogenase gene mutations are strongly associated with paraganglioma of the organ of Zuckerkandl.

Organ of Zuckerkandl paragangliomas (PGLs) are rare neuroendocrine tumors that are derived from chromaffin cells located around the origin of the inferior mesenteric artery extending to the level of the aortic bifurcation. Mutations in the genes encoding succinate dehydrogenase subunits (SDH) B, C, and D (SDHx) have been associated with PGLs, but their contribution to PGLs of the organ of Zuckerkandl PGLs is not known. We aimed to describe the clinical presentation of patients with PGLs of the organ of Zuckerkandl and investigate the prevalence of SDHx mutations and other genetic defects among them.

Radiofrequency ablation of metastatic pheochromocytoma.

In the present report on the preliminary safety and effectiveness of radiofrequency (RF) ablation for pheochromocytoma metastases, seven metastases were treated in six patients (mean size, 3.4 cm; range, 2.2-6 cm).

Comparison of 18F-fluoro-L-DOPA, 18F-fluoro-deoxyglucose, and 18F-fluorodopamine PET and 123I-MIBG scintigraphy in the localization of pheochromocytoma and paraganglioma.

Context: Besides (123)I-metaiodobenzylguanidine (MIBG), positron emission tomography (PET) agents are available for the localization of paraganglioma (PGL), including (18)F-3,4-dihydroxyphenylalanine (DOPA), (18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG), and (18)F-fluorodopamine ((18)F-FDA).

Objective: The objective of the study was to establish the optimal approach to the functional imaging of PGL and examine the link between genotype-specific tumor biology and imaging.

Design: This was a prospective observational study.

Malignant paraganglioma associated with succinate dehydrogenase subunit B in an 8-year-old child: the age of first screening?

Several studies have shown that patients with succinate dehydrogenase subunit B (SDHB) mutations have a very high risk for developing malignant paragangliomas. However, there is no consensus of what age screening for paragangliomas should start. We report a case of an 8-year-old white girl with a 3-year history of catecholamine excess-related complaints who was diagnosed with a malignant SDHB-associated mediastinal paraganglioma.

Use of 6-[18F]-fluorodopamine positron emission tomography (PET) as first-line investigation for the diagnosis and localization of non-metastatic and metastatic phaeochromocytoma (PHEO).

Objective: Imaging modalities available for the localization of phaeochromocytoma (PHEO) include computed tomography (CT), magnetic resonance imaging (MRI), [(123)I]- or [(131)I]-labelled metaiodobenzylguanidine ((123/131)I-MIBG) scintigraphy and 6-[(18)F]-fluorodopamine ((18)F-FDA) positron emission tomography (PET). Our aim was to investigate the yield of (18)F-FDA PET vs. biochemical testing and other imaging techniques to establish the diagnosis and location of PHEO.

Brief communication: radiographic contrast infusion and catecholamine release in patients with pheochromocytoma.

Background: Contrast-enhanced computed tomography (CT) is useful for localizing pheochromocytoma. However, in patients with suspected pheochromocytoma, CT is often canceled or not performed because of the strong belief that intravenous contrast may induce hypertensive crisis.

Objective: To examine whether intravenous low-osmolar contrast administration during CT induces catecholamine release that increases blood pressure or heart rate.

Mediastinal paragangliomas: association with mutations in the succinate dehydrogenase genes and aggressive behavior.

Extra-adrenal pheochromocytomas, otherwise known as paragangliomas (PGLs), account for about 20% of catecholamine-producing tumors. Catecholamine excess and mutations in the genes encoding succinate dehydrogenase subunits (SDHx) are frequently found in patients with PGLs. Only 2% of PGLs are found in the mediastinum, and little is known about genetic alterations in patients with mediastinal PGLs, catecholamine production by these tumors, or their clinical behavior.

Gender-related differences in the clinical presentation of malignant and benign pheochromocytoma.

Signs and symptoms associated with pheochromocytomas are predominantly caused by catecholamine excess, but tend to be highly variable and non-specific. In this study, we evaluated 23 male and 35 female pheochromocytoma patients for symptoms and signs of pheochromocytoma with special regard to gender-related differences in presentation. Total symptom score comparison between genders showed significant differences (12.

Biochemically silent abdominal paragangliomas in patients with mutations in the succinate dehydrogenase subunit B gene.

Context: Patients with adrenal and extra-adrenal abdominal paraganglioma (PGL) almost invariably have increased plasma and urine concentrations of metanephrines, the O-methylated metabolites of catecholamines. We report four cases of biochemically silent abdominal PGL, in which metanephrines were normal despite extensive disease.

Objective: Our objective was to identify the mechanism underlying the lack of catecholamine hypersecretion and metabolism to metanephrines in biochemically silent PGL.