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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phaeochromocytoma is a tumour of the adrenal medulla, which, although rare, is a major cause of correctable hypertension with a prevalence of 0.1-0.5% in the hypertensive population. Clinical symptoms include attacks of paroxysmal headache, sweating, palpitations, stress and a sense of imminent death. Often associated with the above is an increase in blood pressure. Despite the fact that the underlying genetic mechanisms of phaeochromocytoma have been well investigated, they are still incompletely understood. In approximately 80% of cases the tumour occurs sporadically, but it may occur in association with type 2 multiple endocrine neoplasia, type 1 neurofibromatosis or von Hippel-Lindau disease. Molecular evidence suggests that other genes such as SDHD or SDHB may control its development; the possibility of other putative phaeochromocytoma genes is currently being investigated.
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PMID:Clinical and genetic aspects of phaeochromocytoma. 1256 22

To assess the prevalence of genetic mutations in nonsyndromic pheochromocytoma/paraganglioma (PHEO/PGL) patients we have performed a systematic search for mutations in the succinate dehydrogenase (SDH) B, C, and D subunits, von Hippel-Lindau (VHL), and RET genes by direct bidirectional sequencing. Patients were selected from the medical records of hypertension centers. After exclusion of syndromic patients, 45 patients with familial (F+, n=3) and sporadic (F-, n=42) cases of isolated PHEO/PGL were considered. They included 35 patients with PHEO, 7 with PGL, and 3 with head/neck PGL (hnPGL). Three patients with PHEO (2F-, 1F+) presented VHL mutations (P86A, G93C, and R167W), six with PGL (4F-, 2F+) were positive for SDH or VHL mutations (SDHB R230G in two patients, SDHB S8F, R46Q, R90Q, and VHL P81L in one subject each), and one with hnPGL carried the SDHD 348-351delGACT mutation. We have also detected missense (SDHB S163P, SDHD H50R and G12S), synonymous (SDHB A6A, SDHD S68S), and intronic mutations that have been considered nonpathological polymorphic variants. No mutation was found in SDHC or RET genes. Our data indicate that germline mutations of VHL and SDH subunits are not infrequent in familial as well as in sporadic cases of nonsyndromic PHEO/PGL (overall, 12 of 45 probands, 22%). Accordingly, screening for such mutations seems to be justified. However, a more precise characterization of the functional relevance of any observed sequence variant and of other genetic and environmental determinants of neoplastic transformation is essential in order to plan appropriate protocols for family screening and follow-up.
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PMID:Genetic mutation screening in an italian cohort of nonsyndromic pheochromocytoma/paraganglioma patients. 1710 82

Pheochromocytoma (PHEO) is considered to be a rare cause of hypertension. However, if left untreated, PHEOs may lead to fatal hypertensive crises during anesthesia and other stresses. The diagnosis of PHEO is therefore extremely important. A 24-hour blood pressure (BP) pattern per se might be of some diagnostic value due to frequently observed higher BP variability as well as an attenuated night-time BP decrease. So far, germline mutations in five genes have been identified to be responsible for familial PHEOs: the von Hippel-Lindau gene, which causes von Hippel-Lindau syndrome, the RET gene leading to multiple endocrine neoplasia type 2, the neurofibromatosis type 1 gene, which is associated with von Recklinghausen's disease and the genes encoding the B and D subunits of mitochondrial succinate dehydrogenase (SDHB, SDHD), which are associated with familial paragangliomas and PHEOs. Genetic analysis should be offered to those patients with confirmed PHEO who are 50 years old or younger. Plasma-free metanephrines or urinary fractionated metanephrines seem to have higher diagnostic values compared to plasma or urinary catecholamines for the biochemical diagnosis of PHEO. Imaging with (123)I-metaiodobenzylguanidine or (18)F-fluorodopamine PET, if available, are in addition to CT/MRI useful for the detection of multifocal/extra-adrenal forms. Appropriate pharmacologic treatment with subsequent laparoscopic extirpation of PHEO is usually successful in benign forms. There is, however, no convincingly effective mode of treatment in malignant PHEOs.
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PMID:Recent advances in the diagnosis and treatment of pheochromocytoma. 1711 41

Pheochromacytoma is a relatively rare cause of arterial hypertension. Untreated pheochromacytoma may however lead to a fatal hypertensive crisis during anaesthesia or another form of stress. It is therefore important to correctly diagnose this disease. 24-hour monitoring of blood pressure (BP) can already contribute to the diagnosis of pheochromacytoma based on the frequent occurrence of BP variability and the absence of a night-time fall in BP. 5 gene mutations have so far been identified that may be responsible for the familial form of pheochromacytoma: mutation of the von Hippel-Lindau (VHL) gene, leading to the onset of VHL syndrome, mutation of the RET-proto-oncogene in multiple endocrine adenomatosis type 2, mutation of the type 1 gene for neurofibromatosis, which is associated with von Recklinghausen's disease and finally mutation of the genes encoding the B and D subunits of succinated hydrogenase (SDHB, SDHD), which are associated with familial paragangliomas and pheochromacytoma. Genetic analysis should therefore be carried out for all confirmed cases of pheochromacytoma, especially for young people under 50 years of age. Biochemical diagnostics relies mainly on measurements of free metanephrines in plasma or urine, which usually has greater diagnostic weight than plasma, or catecholamines in urine. The diagnosis of extraadrenal or multiple forms can use not only CT/MR but also imaging using the radiopharmaceutical 123I-Metaiodobenzylguanidine (MIBG) or 18F-fluorodopamine PET (only available in the USA). Pharmacological treatment using alpha or beta receptor blockers with subsequent laparoscopic excision of the tumor is usually successful in benign forms of pheochromocytoma. Unfortunately, there are still no convincingly effective therapeutic procedures available for malign forms.
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PMID:[Diagnostic and therapeutic procedures in pheochromocytoma: current trends]. 1757 79

Pheochromocytomas (PHEOs) are rare neoplasms that produce catecholamines and usually arise from the adrenal medulla and are considered to be an adrenal paraganglioma (PGL). Closely related tumors of extraadrenal sympathetic and parasympathetic paraganglia are classified as extraadrenal PGLs. Most PHEOs are sporadic, but a significant percentage (approximately 25%) may be found in patients with germline mutations of genes predisposing to the development of von Hippel-Lindau disease, neurofibromatosis 1, multiple endocrine neoplasia type 1 (MEN1) and 2 (MEN2), and the PGL/PHEOs syndrome, based on the described mutations of the genes for succinate dehydrogenase subunit D (SDHD), B (SDHB), and C (SDHC). As one out of four PHEOs turns out to be a hereditary clinical entity, screening for genetic alterations is important, as it provides useful information for a rational diagnostic approach and management. This review discusses the genetics, the pathophysiology of hypertension, the clinical picture, the biochemical and imaging diagnosis, and the preferred therapeutic approach for PGLs/PHEOs. Furthermore, it emphasizes the need for genetic testing in cases with apparently sporadic PHEOs.
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PMID:Pheochromocytoma: an update on genetics and management. 1804 48

Pheochromocytomas/paragangliomas(PHEOs/PGLs) are rare but treacherous catecholamine-producing tumors which, if overlooked or improperly treated, will almost invariably prove fatal. Patients with MEN2 PHEOs have a high incidence of paroxysmal attacks and a higher prevalence of hypertension and other cardiovascular problems than do patients with Von-Hippel-Lindau (VHL) PHEOs. Compared to measurements of deconjugated metanephrines, plasma concentrations of free metanephrines are relatively independent of renal function and therefore more suitable for diagnosis of PHEO/PGL. Recently, the focus of Positron Emission Tomography (PET) imaging for these tumors has been the localization of PHEO. Although a limited number of studies are available, [18F]-fluorodopamine ([18F]DA) PET has been found to be the best overall imaging modality in the localization of PHEO. For adrenal PHEOs, this method seems to be comparable to other functional modalities such as [18F]-fluorodopa ([18F]DOPA) PET or [123I]-metaiodobenzylguanidine ([123I]MIBG)scintigraphy. For extraadrenal PHEOs, data are limited and more extensive studies are needed. In patients with metastatic PHEO, the sensitivity of [18F]DA PET is superior to [123I]MIBG. The so called "flip-flop" imaging showing superiority of non-specific [18F] flurodeoxyglucose (FDG) PET over specific [18F]DA PET has been described in rapidly progressive, often metastatic SDHB-associated PHEOs. Whether these data reflect PHEO cell dedifferentiation (e.g. losing Norepinephrine Transporter-NET) or increased metabolic rate remains to be established.
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PMID:Diagnosis of pheochromocytoma with special emphasis on MEN2 syndrome. 1957 Jul 38

Phaeochromocytomas are catecholamine-secreting tumours that arise from chromaffin cells of the adrenal medulla and extra-adrenal sites. Extra-adrenal phaeochromocytomas are called paragangliomas. A diagnosis of phaeochromocytoma is suspected by typical paroxysmal symptoms, unusual or refractory hypertension, discovery of an adrenal incidentaloma or a family history of phaeochromocytoma or paraganglioma, possibly associated with other genetic syndromes (multiple endocrine neoplasia type 2 A or B, neurofibromatosis type 1 and von Hippel-Lindau disease). It can be confirmed by measurements of urinary or plasma fractionated catecholamines and metanephrines. The best diagnostic performances are achieved by metanephrines. Twenty-four hour urine fractionated metanephrines are still recommended as a screening test but some experts prefer plasma measurements in high-risk patients. Increased serum chromogranin-A levels, combined with high catecholamine or metanephrine in a patient with normal renal function is also a tool, virtually diagnostic of phaeochromocytoma. Recent studies have suggested that 25% of patients with phaeochromocytoma have germline mutations of several genes (NF1, VHL, SDHD, SDHB and RET). Thus, genetic testing should be carried out according to an algorithm of risk factors and specific characteristics. Once a biochemical diagnosis of phaeochromocytoma is made, a CT scan or MRI of the abdomen and pelvis should be performed first. If these investigations remain negative, the chest and neck should be explored. After anatomical imaging, functional imaging by 123I-MIBG should be considered. If the MIBG scan is negative, other imaging modalities have recently proven to be useful (PET, Octreoscan). After localization, the treatment of phaeochromocytoma is a surgical resection, which may be laparoscopic. Preoperative preparation with alpha- and beta-adrenergic blockade and/or calcium channel blockers associated with volume expansion is essential. Malignant phaeochromocytoma is rare and its treatment still unsatisfying. Phaeochromocytoma during pregnancy is also rare and its diagnosis easily missed because of its clinical resemblance to pre-eclampsia.
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PMID:Phaeochromocytoma: state-of-the-art. 2051 23

Pheochromocytoma is a tumor that originates from the adrenal cortex and sympathetic chains. Most pheochromocytomas are sporadic, whereas others occur as hereditary syndromes. Familial pheochromocytoma has been frequently found in association with various mutations in genes of the succinate dehydrogenase family. A 21-year-old Korean male presented with recurrent chest tightness, severe headache, and hypertension. He was diagnosed as pheochromocytoma based on a 24-hour urine test, abdominal computed tomography, and (131)I-MIBG scintigraphy. Genomic DNA was extracted from the patient's whole blood. Primers covering all the coding regions and flanking introns of succinate dehydrogenase (SDH) B, C and D genes were designed and synthesized, and a DNA sequence analysis was performed using the polymerase chain reaction. Direct sequencing of the SDHB gene revealed a deletion of nucleotide 757 (thymidine) in exon 7. This thymidine deletion caused a shift in the reading frame that created a downstream stop codon and a truncated product (p.Cys253ValfsX5). Although the patient had no family history of pheochromocytoma, his father had the same mutation. We report a novel SDHB gene mutation from a Korean family with pheochromocytoma. This is the first report of pheochromocytoma with a confirmed SDHB germline mutation in Korea.
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PMID:A novel mutation of the succinate dehydrogenase B gene in a Korean family with pheochromocytoma. 2056 60

Paragangliomas are tumors arising from sympathetic and parasympathetic tissues. The classic associated syndromes are neurofibromatosis type 1, multiple endocrine neoplasia type 2 and von Hippel-Lindau. Germline mutations of succinate dehydrogenase subunits genes, are associated with familial paraganglioma syndromes 1,2,3 and 4. We report a 29-year-old woman with a family background of pheochromocytoma and history of paroxysmal headache, nausea, sweating, palpitations, associated with severe hypertension. The patient had elevated plasma noradrenalin and urinary normetanephrines. Imaging studies revealed three retroperitoneal extra-adrenal masses. The clinical and laboratory study of classic syndromes associated with paraganglioma was negative. The patient was operated and the pathological study of the surgical specimen was consistent with paragangliomas. The genetic study showed a mutation in the SDHB succinate dehydrogenase gen, Exon 2 of CCTCA c.300_304 (p.P56delYfsX5).
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PMID:[Multiple paragangliomas associated to a SDHB gene mutation: report of one case]. 2244 54

Pheochromocytomas and paragangliomas are tumors arising from chromaffin cells. These tumors produce catecholamines and are typically found with symptoms and signs that may include hypertension (persistent or episodic), palpitations, headache and sweating. So far, 10 different genes have been associated with both tumors and other genes are expected to be detected. Pheochromocytoma and paraganglioma can occur as a part of genetic syndromes - familial paragangliomas (SDH genes, SDHAF2 gene), von Hippel-Lindau syndrome (VHL gene), multiple endocrine neoplasia type 2 (RET gene), and neurofibromatosis type 1 (NF1 gene). These tumors may be the first and only manifestation of these genetic syndromes. Patients with SDHB mutations are at high risk to develop malignant disease and unfortunately current therapeutic options for malignant form of disease are poor. Genetic testing plays a key role in the management of these tumors and therefore not only index patients with pheochromocytoma but also relatives should be tested. Management of this disease requires multidisciplinary cooperation and should be performed in the specialized medical centres.
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PMID:[Hereditary pheochromocytoma and paraganglioma]. 2292 Feb 2


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