Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0031511 (pheochromocytoma)
 14,622 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This two-part study reviews data from a recently developed colony of New Zealand white rabbits with familial, nonsyndromic unilateral coronal suture synostosis, and this second part presents neuropathological findings and age-related changes in intracranial volume (ICV) and intracranial pressure (ICP) in 106 normal rabbits and 56 craniosynostotic rabbits from this colony. Brain morphology and anteroposterior length were described in 44 rabbit fetuses and perinates (27 normal; 17 synostosed). Middle meningeal artery patterns were qualitatively assessed from 2-D PCC MRI VENC scans and endocranial tracings from 15, 126-day-old rabbits (8 normal, 7 rabbits with unicoronal synostosis). Brain metabolism was evaluated by assessing 18F-FDG uptake with high-resolution PET scanning in 7, 25-day-old rabbits (3 normal, 4 with unicoronal or bicoronal synostosis). Intracranial contents and ICV were assessed using 3-D CT scanning of the skulls of 30 rabbits (20 normal,10 with unicoronal synostosis) at 42 and 126 days of age. Serial ICP data were collected from 66 rabbits (49 normal; 17 with unicoronal synostosis) at 25 and 42 days of age. ICP was assessed in the epidural space using a Codman NeuroMonitor microsensor transducer. Results revealed that cerebral cortex morphology was similar between normal and synostosed fetuses around the time of synostosis. Significantly (P<0.05) decreased A-P cerebral hemisphere growth rates and asymmetrical cortical remodeling were noted with increasing age in synostotic rabbits. In addition, rabbits with unicoronal suture synostosis exhibited asymmetrical middle meningeal artery patterns, decreased and asymmetrical brain metabolism, a "beaten-copper" intracranial appearance, significantly (P<0.05) decreased ICV, and significantly (P<0.01) elevated ICP compared with normal control rabbits. The advantages and disadvantages of these rabbits as a model for human familial, nonsyndromic unicoronal suture synostosis are discussed, especially in light of recent clinical neuropathological, ICV, and ICP findings recorded in human craniosynostotic studies.
 ...
PMID:A rabbit model of human familial, nonsyndromic unicoronal suture synostosis. II. Intracranial contents, intracranial volume, and intracranial pressure. 969 36

Radionuclides used for cancer patients are produced by cyclotron or nuclear reactor. Thyroid cancer patients with lung and/or bone metastasis have been successfully treated with 131I for more than 50 years. But for the diagnosis of cancer patients, 99mTc is superior to 131I, and many 99mTc labeled compounds have been developed, such as for the diagnosis of bone metastasis, liver and kidney diseases and so on. Recently PET studies using 18F-labeled FDG have been widely performed and excellent results are reported in many cancer patients such as lung, colorectal, malignant lymphoma, malignant melanoma and so on. Radionuclides with beta emitter are suitable for the therapy of various cancers. 131I labeled anti-CD-20 monoclonal antibodies and 131I-MIBG are used for the therapy of lymphoma and pheochromocytoma, respectively. For the palliation of metastatic bone pain, 89Sr, 153Sm or 186Re is promising, because these radionuclides can be administered on an outpatients basis.
 ...
PMID:[Progress of nuclear oncology]. 1047 78

Medullary thyroid carcinoma (MTC) originates in the parafollicular cells (C cells) of the thyroid, secreting both calcitonin and CEA. Genetic and biochemical testing allow early pre-clinical identification of familial forms. Sporadic MTC usually presents as a solitary palpable thyroid nodule and in most cases the definitive diagnosis is established only at the time of surgery. Nuclear medicine procedures, which play a minor role in the preoperative evaluation of MTC, are essential in postoperative follow-up to detect residual and/or recurrent tumor. A number of radiopharmaceuticals are able to visualize MTC lesions with considerable advantages in diagnosis and prognosis, some of them having also a therapeutic role. Among them, 99mTc[V]DMSA shows the highest diagnostic sensitivity and is considered by many authors the radiopharmaceutical of choice in the postoperative work-up of MTC. Radioiodinated MIBG, in spite of its high specificity has a poor sensitivity (30%); however it is useful for the identification of pheochromocytoma and, in patients showing MIBG uptake in tumoral lesions, high activities of 131I-MIBG may be used for therapy. 111In labeled octreotide detects lesions which express somatostatin receptors; a positive scintigraphic result seems to give also prognostic information (higher uptake in slow-growing lesions) and provides the basis for treatment with octreotide or lanreotide and 111In or 90Y-labeled octreotide analogues. Interesting perspectives are offered by 18F-FDG PET and monoclonal anti-CEA labeled antibodies; the latter may be also used for therapy.
 ...
PMID:Role of nuclear medicine in the diagnosis and therapy of medullary thyroid carcinoma. 1137 May 45

Catecholamine-secreting metastatic carcinoid should be considered in differential diagnosis of malignant pheochromocytoma. Paroxysmal functioning or hormonally silent gastroenteropancreatic neuroendocrine tumors (GEP NETs) require repeat biochemical measurements and sensitive anatomic and functional imaging studies overlapping those for malignant pheochromocytoma. This report presents clinical, laboratory, and radiologic findings in a patient presenting with heart rate variability; vasoactive headaches reactive to ethanol, tyramine and tryptophan; labile blood pressure; diaphoresis; diarrhea; abdominal pain; unexplained pancreatitis; joint pain; and paroxysmal flushing with pallor. GI studies (including endoscopic ultrasound) and multiple imaging modalities (including 2D CT, MRI with gadolinium, [18]FDG PET/CT, [123I]MIBG, and SRS [111In]Octreotide [OctreoScan]) were not diagnostic. 24-h BP, Holter and 30-day cardiac event monitors plus urinary biochemical studies consistently suggested catecholamine-synthesizing NET. NIH plasma metanephrines studies and [6]-[18F]Fluorodopamine PET ruled out malignant pheochromocytoma (pheo). Repeated studies showed persistently abnormal GEP NET biomarkers and urinary catecholamines. Capsule endoscopy revealed suspicious submucosal lesions throughout the small intestine. Dual-phase 64-slice multidetector computed tomography (MDCT) with 3D volumetric reconstruction of the abdomen and pelvis revealed multiple diffuse liver metastases and three extrahepatic lesions consistent with metastatic carcinoid. In combination, intensive biochemical testing repeated over time, dual-phase 64-slice MDCT with 3D image reconstruction and volume-rendering (VR) technique, and advanced radionuclide imaging are required to detect NETs' sporadic or paroxysmal functioning, rule out extra-adrenal pheochromocytoma, and localize and characterize metastatic carcinoid. If pheochromocytoma is ruled out, yet symptoms and biochemical markers for catecholamine excess are present, then carcinoid and other amine-precursor-uptake decarboxylation (APUD) tumors must remain in the differential diagnosis.
 ...
PMID:Catecholamine-secreting metastatic carcinoid as differential diagnosis in pheochromocytoma: clinical, laboratory, and imaging clues in the search for the lurking neuroendocrine tumor (NET). 1710 73

Pheochromocytomas offer the opportunity to explore multiple pathophysiological mechanisms through functional imaging. MIBG scintigraphy and PET scanning with tracers of the sympathetic nervous system are based on uptake of catecholamines and catecholamine-like compounds by hNET, the human norepinephrine transporter. In-111 pentetreotide scanning involves the imaging of somatostatin receptors on the cellular surface of tissues. FDG PET scanning examines the transport and incorporation of FDG into cells. We present a patient with malignant pheochromocytoma who underwent multitracer imaging to characterize the tumor and probe its pathophysiology to direct a therapeutic approach. This case underscores the inherent difficulties in the diagnosis and localization of malignant pheochromocytomas. Multiple approaches to functional and anatomic imaging may be required to fully delineate the extent of disease and similarly to direct radionuclide-based therapy.
 ...
PMID:Multimodality imaging of malignant pheochromocytoma. 1711 86

We performed a retrospective analysis of 71 subjects with metastatic pheochromocytoma and paraganglioma (30 subjects with mutation of succinate dehydrogenase enzyme subunit B (SDHB) gene and 41 subjects without SDHB mutation). Sixty-nine percent presented with bone metastases (SDHB +/-: 77% vs 63%), 39% with liver metastases (SDHB +/-: 27% vs 47%), and 32% with lung metastases (SDHB +/-: 37% vs 29%). The most common sites of bone involvement were thoracic spine (80%; SDHB+/-: 83% vs 77%), lumbar spine (78%; SDHB +/-: 78% vs 75%), and pelvic and sacral bones (78%; SDHB +/-: 91% vs 65%, P=0.04). Subjects with SDHB mutation also showed significantly higher involvement of long bones (SDHB +/-: 78% vs 30%, P=0.007) than those without the mutation. The best overall sensitivity in detecting bone metastases demonstrated positron emission tomography (PET) with 6-[(18)F]-fluorodopamine ([(18)F]-FDA; 90%), followed by bone scintigraphy (82%), computed tomography or magnetic resonance imaging (CT/MRI; 78%), 2-[(18)F]-fluoro-2-deoxy-d-glucose ([(18)F]-FDG) PET (76%), and scintigraphy with [(123/131)I]-metaiodobenzylguanidine (71%). In subjects with SDHB mutation, imaging modalities with best sensitivities for detecting bone metastases were CT/MRI (96%), bone scintigraphy (95%), and [(18)F]-FDG PET (92%). In subjects without SDHB mutations, the modality with the best sensitivity for bone metastases was [(18)F]-FDA PET (100%). In conclusion, bone scintigraphy should be used in the staging of patients with malignant pheochromocytoma and paraganglioma, particularly in patients with SDHB mutations. As for PET imaging, [(18)F]-FDG PET is highly recommended in SDHB mutation patients, whereas [(18)F]-FDA PET is recommended in patients without the mutation.
 ...
PMID:Role of positron emission tomography and bone scintigraphy in the evaluation of bone involvement in metastatic pheochromocytoma and paraganglioma: specific implications for succinate dehydrogenase enzyme subunit B gene mutations. 1831 Feb 97

Pheochromocytomas are rare tumors arising from chromaffin cells of adrenal medullary or extra-adrenal paraganglionic tissue. These tumors are characterized by synthesis, storage, metabolism and secretion of catecholamines. Similar to the sympathetic nervous system, pheochromocytomas express cellular norepinephrine transporters (NET) through which catecholamines can enter pheochromocytoma cells to be stored in vesicles. Metaiodobenzylguanidine (MIBG) resemblance to norepinephrine and its good affinity and uptake by NET resulted in its use in pheochromocytoma diagnosis from 1981. Both [(123)I]MIBG and [(131)I]MIBG (lower sensitivity) scintigraphy are used for localization of these tumors. Recent discoveries of different hereditary syndromes associated with pheochromocytomas led to the identification of several and new distinct genotype-phenotype associations. Importantly, with this distinction of clinical phenotypes, MIBG was found to have a different performance in subsets of pheochromocytoma patients. Reduced sensitivity of MIBG scintigraphy in some familial paraganglioma syndromes, malignant disease and extra-adrenal paragangliomas has been found. Therefore, newer compounds, especially for positron emission tomography (PET), such as [(11)C]hydroxyephedrine ([(11)C]HED), [(18)F]fluoro-2-deoxy-D-glucose ([(18)F]FDG), [(18)F]fluoro-dihydroxyphenylalanine ([(18)F] FDOPA) and [(18)F]fluorodopamine ([(18)F]FDA) have emerged and were found to be superior to MIBG in the localization of certain types of pheochromocytoma and paragangliomas. Finally, using [(131)I]MIBG represents an important treatment option in patients with malignant pheochromocytoma, but the development of newer treatment modalities is expected. In this review, we provide the reader with an overview of the current standing of [(123)I]- and [(131)I]MIBG in diagnosis and treatment of pheochromocytoma amongst the newer PET imaging agents.
 ...
PMID:Detection and treatment of pheochromocytomas and paragangliomas: current standing of MIBG scintigraphy and future role of PET imaging. 1908 95

A 53-year-old man was admitted to Ehime University Hospital because of a left adrenal tumor, which was detected by a routine medical examination. Blood pressure was 124/74 mmHg and the pulse rate was 80/min and regular. Computed tomography showed the tumor consisting mainly of low-density areas and partly of heterogeneous density areas. Magnetic resonance imaging demonstrated that the tumor consisted mainly of low intensity areas, partly of heterogeneous intensity areas determined by T1-weighted images; T2-weighted images showed that the tumor consisted mainly of high intensity areas and partly of heterogeneous intensity areas. These images suggested that the left adrenal tumor was a pheochromocytoma. The concentrations of serum adrenaline and noradrenaline were slightly elevated (adrenaline 0.11 ng/mL (normal: < 0.1) and noradrenaline 1.11 ng/mL (normal 0.1 - 0.5)). Although 131I-meta-iodobenzylguanidine (MIBG) scintigraphy did not show an accumulation of the tracer, 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) showed an increased accumulation of the tracer in the left adrenal tumor. These results were suggestive of the diagnosis of pheochromocytoma, and left adrenalectomy was performed by endoscopy. He was finally diagnosed with pheochromocytoma. The detection rate of pheochromocytoma by FDG-PET is not very high and has been reported to be about 70 %. However, FDG-PET may be useful for detecting local recurrence or distant metastasis, in patients with MIBG-negative pheochromocytoma.
 ...
PMID:[Case of 131I-meta-iodobenzylguanidine (MIBG) scintigraphy-negative and 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET)-positive pheochromocytoma]. 1971 65

Medullary thyroid cancer (MTC) has a variable clinical presentation. We present 3 patients with this endocrine tumour. The first patient, a 41-year-old woman complaining of diarrhoea, a painful abdomen, weight loss and sensibility disorders in both legs, had metastases of MTC in the spine, with little progression during 2 years of follow-up. The second patient, a 64-year-old woman suffering from a painful nodule in the neck and a painful shoulder, was diagnosed with MTC and liver, lung and bone metastases. She died after 14 months due to progressive disease. The third patient, an 81-year-old woman with hyperparathyroidism, was coincidentally diagnosed with MTC after goitre surgery at the age of 67. When she was evaluated for rising calcitonin levels, a pheochromocytoma was found. RET mutation analysis confirmed a MEN2A syndrome. Current diagnostic procedures of MTC may include positron emission tomography with 18F-deoxyglucose (FDG-PET) and 18F-diphenylalanine (DOPA-PET). MTC is usually treated surgically. Tyrosine kinase inhibitors appear to offer potential new therapeutic possibilities.
 ...
PMID:[Medullary thyroid cancer, a tumour with many appearances]. 2085 19

Due to broader use of conventional imaging techniques, adrenal tumors are detected with increasing frequency comprising a wide variety of different tumor entities. Despite improved conventional imaging techniques, a significant number of adrenal lesions remain that cannot be easily determined. A particular diagnostic challenge are lesions in patients with known extra-adrenal malignancy because these patients frequently harbor adrenal metastases. Furthermore, adrenal masses with low fat content and no detectable hormone excess are difficult to diagnose properly. Fine needle biopsy is invasive, often unsuccessful, and puts patients at risk, e. g., in cases of pheochromocytoma or adrenal cancer. Noninvasive characterization using radiotracers has therefore been established in recent years. (18)F-FDG PET helps to differentiate benign from malignant lesions. However, it does not distinguish between adrenocortical or nonadrenocortical lesions (e.g., metastases or adrenocortical carcinoma). More recently, enzyme inhibitors have been developed as tracers for adrenal imaging. Metomidate is most widely used. It binds with high specificity and affinity to CYP11B enzymes of the adrenal cortex. As these enzymes are exclusively expressed in adrenocortical cells, uptake of labeled metomidate tracers has been shown to be highly specific for adrenocortical neoplasia. (11)C-metomidate PET and (123)I-iodometomidate SPECT imaging has been introduced into clinical use. Both tracers not only distinguish between adrenocortical and nonadrenocortical lesions but are also able to visualize metastases of adrenocortical carcinoma. The very specific uptake has recently led to first application of (131)I-iodometomidate for radiotherapy in ACC. In conclusion, metomidate-based imaging is an important complementary tool to diagnose adrenal lesions that cannot be determined by other methods.
 ...
PMID:Metomidate-based imaging of adrenal masses. 2212 41


1 2 3 4 5 6 Next >>