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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Following adrenal phlebography, obstruction of the large bowel associated with adrenergic crisis was observed in a 60 year old patient with pheochromocytoma. As in other published cases of ileus associated with pheochromocytoma, high urinary catecholamine concentrations were found in our patient and the tumor resected at surgery was large. As phlebography immediately preceded the onset of ileus and hypertensive crisis, it is postulated that angiography led to massive secretion of catecholamines, which caused the hypertensive crisis as well as the ileus. The possible mechanisms by which phlebography may lead to adrenergic crisis are discussed. It is concluded that in suspected pheochromocytoma all angiographic examinations should be carried out under simultaneous treatment with alpha-blocking agents.
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PMID:[Paralytic ileus in pheochromocytoma. Possible correlation with an attempt at adrenal phlebography]. 1 62

A 12-year-old boy with a norepinephrine-secreting pheochromocytoma that caused hypertension resistant to oral alpha adrenergic blockade is reported. Resistance to alpha adrenergic blocking agents developed when the patient's daily propranolol dosage was lowered from 10 to 1 mg/kg. Subsequently, alpha methyl tyrosine, an inhibitor of tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis, controlled the patient's blood pressure and was associated with reduction in total urinary catecholamine excretion. Norepinephrine content of the tumor and uninvolved adrenal gland removal at surgery was reduced. These findings confirm that alpha methyl tyrosine inhibited in vivo synthesis of catecholamines.
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PMID:Childhood pheochromocytoma: treatment with alpha methyl tyrosine for resistant hypertension. 1 59

Out of the discovery of concurrent multiple endocrine neoplasms has evolved the concept of multiple endocrine adenomatosis (MEA1 and MEA2). Medullary carcinoma of the thyroid gland is the most constant facet of MEA2 and is derived from C-cells of the neural crest. These cells, resembling parafollicular cells of lower animals, elaborate calcitonin which acts as a sensitive signal of the presence of the tumor. Ninety per cent of MCT occurs sporadically; in 10% the tumor presents as an atuosomal dominant trait. Other endocrinopathies, especially pheochromocytomas, are present in 70% of cases. The lesions are "cold" on iodine radioisotope scan. On microscopic examination, the appearance of amyloid is characteristic. Regional lymph node metastasis occurs early. The tumor deserves appropriate aggressive management. Surgical therapy should begin early and vigorously with the minimum procedure being total thyroidectomy. Frequent lymph node metastasis speaks for the need for regional neck dissection extended into the superior mediastinum. The search for, and the treatment of, the frequently associated endocrinopathies is essential. Pheochromocytoma must be suspected and eradicated before treatment of the thyroid tumor. A genetic workup should be included.
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PMID:Medullary carcinoma of the thyroid gland. 2 13

We have established a clonal cell line, PC-G2, from an experimentally induced rat pheochromocytoma. Administration of nerve growth factor to PC-G2 causes a 4- to 8-fold induction in the specific activity of tyrosine hydroxylase [tyrosine 3-monooxygenase; L-tyrosine,tetrahydropteridine:oxygen oxidoreductase(3-hydroxylating); EC 1.14.16.2]. The response is elicited in a dose-dependent fashion, at concentrations above 0.1 microgram/ml. Antiserum to nerve growth factor inhibited the induction of tyrosine hydroxylase. Dexamethasone enhances the nerve growth factor-mediated elevation of tyrosine hydroxylase. After 3--4 days of exposure to nerve growth factor the maximal induction of tyrosine hydroxylase is seen, although a significant increase can be observed after 24 hr. In contrast to the PC-12 cell line (derived from the same tumor), in which neurite outgrowth occurs in response to nerve growth factor, there is no morphological change or alteration in growth rate of PC-G2 cells after exposure to nerve growth factor.
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PMID:Nerve growth factor-mediated induction of tyrosine hydroxylase in a clonal pheochromocytoma cell line. 3 87

The antepartum diagnosis of pheochromocytoma concurrent with pregnancy has been reported in 42 cases. These cases were analyzed for the effect of preoperative alpha blockade and of the timing of surgical intervention. Alpha blockade, when performed promptly in all pregnant patients in whom the diagnosis of pheochromocytoma was made, reduced fetal mortality regardless of the gestational age. In addition, when the diagnosis of pheochromocytoma was made in the third trimester of pregnancy and alpha blockade was adequately maintained, a combined procedure of cesarean section and tumor resection was best. If the tumor could not be located during a combined procedure, delivery followed by delayed resection was not associated with any greater maternal mortality. The surgical approach required for patients diagnosed in the first or second trimester was less clear. Although alpha blockade is indicated in such early patients, it cannot yet be determined if a delay in the tumor excision will subject the mother and fetus to a greater risk than the accepted practice of early resection with delayed delivery.
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PMID:Alpha blockade and surgical intervention of pheochromocytoma in pregnancy. 3 55

Plasma catecholamines have been used for diagnosis and computerized tomography scanning for localization in 21 patients with proved pheochromocytoma. Blood catecholamines were obtained in 20 of the patients and were elevated significantly in every instance. Successful localization of the tumor was accomplished by excretory urography in only 47% of the cases, by selective angiography in 85% and by abdominal computerized tomography scanning in 88%. In 7 patients preoperative identification and localization of the tumor were determined correctly by computerized tomography scanning alone. Data in our series suggest that the diagnosis and localization of pheochromocytoma can be accomplished usually by a simple blood test and body scan. More elaborate and sometimes hazardous studies should be necessary only in exceptional cases, usually with tumors less than 3 cm. in diameter.
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PMID:A simplified, cost-effective approach to the diagnosis of pheochromocytoma. 12 Sep 92

Currently the only treatment available for inoperable pheochromocytoma is symptomatic and palliative with alpha- and beta- adrenergic blockade. Pheochromocytoma is a tumor of chromaffin tissue derived from the neural crest and closely related to other APUD (amine precursor uptake and decarboxylation) cell tumors, including those of the pancreatic islets. Streptozocin has been used with varying success in some of these tumors and therefore merited a trial in pheochromocytoma. We used streptozocin to treat two patients with inoperable pheochromocytoma; the drug failed to have any effect, either on catecholamine excretion or tumor growth.
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PMID:Attempted treatment of inoperable pheochromocytoma with streptozocin. 14 Dec 42

Twenty-eight patients with the clinical diagnosis of pheochromocytoma were studied by adrenal venography and catecholamine determination in selective venous blood sampling. Results of this technique are correlated to pathologic findings. 87% of the existing pheochromocytomas were correctly identified. In cases with corresponding venographic and laboratory results correct preoperative tumor localization was established in 97%. False interpretations are discussed in relation to the phlebographic findings and the assay of the catecholamines.
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PMID:[Venographic and laboratory investigation of pheochromocytoma (author's transl]. 14 74

A patient presenting with von Hippel-Lindau's disease, syringomyelia, bilateral pheochromocytoma and a multihormonal pancreatic tumor is described. We suggest that this syndrome results from a complex neuroendocrine disorder.
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PMID:Von Hippel-Lindau's Disease, syringomyelia and multiple endocrine tumors: a complex neuroendocrinopathy. 15 Jan 14

Glucagon activated adenylate cyclase in a homogenate of a pheochromocytoma over the concentration range 1 times 10 minus 8M to 1 times 10 minus 6M. Several other hormones including adrenocorticotropin, thyrotropin, parathyroid hormone and histamine were without effect. The tumor glucagon receptor was characterized and found to be similar in several ways to the glucagon receptor previously reported in normal tissue such as liver and heart. One, the receptor specifically bound 125-I-glucagon. Two, solubilization of the pheochromocytoma abolished glucagon-activation of the adenylate cyclase. Three, glucagon-responsiveness of the adenylate cyclase was partially restored by the addition of phosphatidylserine to the incubations. One major difference was observed between the glucagon receptor in tumor tissue and that in liver and heart, namely, a marked lability in 125-I-glucagon binding and adenylate cyclase activity. Within four days, despite storage in liquid nitrogen, 75% of the binding activity and all of the adenylate cyclase activity in the solubilized preparation were lost. The factor(s) responsible for this lability remains unidentified.
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PMID:Characterization of the glucagon receptor in a pheochromocytoma. 16 16


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