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

Exciting developments in knowledge of primary aldosteronism include description of new subtypes and elucidation of the genetic basis of one variety. Furthermore, relatively simple biochemical screening (aldosterone/renin ratio) has disclosed that primary aldosteronism is more common than previously thought, by diagnosing patients at an earlier, normokalaemic stage. The mutant gene discovered in the glucocorticoid-suppressible variety (FHI) codes for an aldosterone biosynythetic enzyme normally controlled by angiotensin II, and now controlled by corticotropin. The zona fasciculata is hyperplastic and makes aldosterone and "hybrid steroids" 18-oxocortisol and 18-hydroxycortisol in excess, in response to ACTH but not to angiotensin II. Adrenal tumours have not yet been described in this condition. Aldosterone-producing adenomas (Conn's syndrome) are also commonly composed of zona fasciculata-like cells, make "hybrid steroids" in excess and are very sensitive to ACTH but not to angiotensin II. We have described a new variety of aldosterone-producing adenoma which is responsive to angiotensin II (AII-responsive APA), consists of at least 20% zona glomerulosa-like cells, and does not make "hybrid steroids" in excess. We have also described a new familial variety of primary aldosteronism that includes tumours and is not glucocorticoid-suppressible (FHII). We propose that primary aldosteronism is a spectrum of genetic diseases expressed as either hyperplasia or neoplasia, and that morphological and genetic diversity explains biochemical and clinical behaviour.
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PMID:Primary aldosteronism: hypertension with a genetic basis. 135 75

Seven members with multiple endocrine neoplasia type 2B from a 15-member family have been followed for 18 years. All affected had the neuroma phenotype in a distribution compatible with autosomal dominant inheritance. The phenotype features have allowed 100% initial and continuing prediction of affected versus nonaffected status in as early as 1.5 years. Among the affected: immunoreactive plasma calcitonin (iCT) concentration was high in 100%; thyroid palpation was false-negative in 71%; and thyroid scintiscan was false-negative in 83%. All had total thyroidectomy, plus lymphadenectomy in three, for bilateral medullary thyroid carcinoma (MTC) or C-cell hyperplasia (in the youngest). None has died directly from MTC. The index case died at age 68 and his son at age 32 years from complications of the syndrome. All but the youngest have continuing high iCT concentrations. No patient has had parathyroid disease. During preoperative calcium infusion, immunoreactive serum parathyroid hormone concentration declined by 35% to 84% of basal. At operation, macroscopically and microscopically normal parathyroid glands were found in all. No patient has had chemical suggestion of pheochromocytomas: at postmortem the index case had no adrenal medullary disease; his son had bilateral nodular adrenal hyperplasia; his daughter has had adrenal medullary hyperplasia and a renin-secreting juxtaglomerular tumor. Initially nonaffected members remain so.
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PMID:Multiple endocrine neoplasia type 2B: eighteen-year follow-up of a four-generation family. 136 13

Increasing evidence indicates that angiotensin II can be formed by juxtaglomerular cells (JGC) and cosecreted with renin. We investigated the existence of this local renin-angiotensin system in a human JGC tumor, using an in vitro superfusion. The JGC tumor was found concomitantly to release renin and angiotensin I and II. Sequential addition of atrial natriuretic peptide, dopamine, and a somatostatin analog in the superfusion did not affect renin or angiotensin I and II release. The data provide evidence that the human JGC tumor in vitro generates angiotensin II, and supports its possible role as a local in vivo regulator of kidney function.
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PMID:Concomitant release of renin, angiotensin I, and angiotensin II during superfusion of human juxtaglomerular cell tumor. 138 67

In a 21-year-old Caucasian women with von Hippel-Lindau disease, norepinephrine-producing adrenal pheochromocytoma was identified as the underlying cause of severe hypertension. She was found to have extremely elevated levels of circulating renin and aldosterone, and she was markedly hypokalemic. Administration of captopril further enhanced renin secretion, while her blood pressure improved. The patient became normokalemic following tumor removal, and her blood pressure decreased to normal levels with reestablishment of normal circadian blood pressure rhythm. This case demonstrates that, in the absence of renovascular or malignant hypertension, pheochromocytoma can be the underlying cause for the clinical syndrome of hypertension associated with severe hypokalemia and hyperreninemic hyperaldosteronism.
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PMID:Hyperreninemia and secondary hyperaldosteronism in a patient with pheochromocytoma and von Hippel-Lindau disease. 143 50

19-Nor-deoxycorticosterone (19-nor-DOC), a hypertensinogenic mineralocorticoid, equipotent with aldosterone and independent of the renin-angiotensin system, is synthesized in the kidney and excreted in excess in the urine of patients with aldosterone-producing adenomas. This current study evaluated the adrenal and renal venous levels of aldosterone and 19-nor-DOC after adrenal and renal venous catheterization and blood sampling in five patients with aldosterone-producing adenomas. Aldosterone (mean +/- SEM) in the adrenal vein ipsilateral to the tumor (469 +/- 293 ng/dl) was higher than in the contralateral vein (70 +/- 59 ng/dl). 19-Nor-DOC (mean +/- SEM) was also higher in the ipsilateral (548 +/- 286 ng/dl) than in the contralateral (51 +/- 14 ng/dl) adrenal vein. In the renal veins, ipsilateral aldosterone (2.2 +/- 0.8 ng/dl) and 19-nor-DOC (12.2 +/- 2.4 ng/dl) were respectively similar to contralateral aldosterone (1.5 +/- 0.5 ng/dl) and 19-nor-DOC (14.6 +/- 1.3 ng/dl), whereas 19-nor-DOC was higher than aldosterone in each renal vein. The present study demonstrates that 19-nor-DOC is produced, not only from the kidneys, but also from the ipsilateral adrenal of patients with aldosterone-producing adenomas. The ipsilateral adrenal 19-nor-DOC production is comparable to that of aldosterone, suggesting that 19-nor-DOC may be contributing to the hypertension and hypokalemia in this disease. In the contralateral adrenal, aldosterone is suppressed to a greater extent than 19-nor-DOC, suggesting that these two steroids are under the influence of two different regulatory mechanisms.
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PMID:19-Nor-deoxycorticosterone production from aldosterone-producing adenomas. 155 68

A case of secondary hypertension due to an aldosteronoma coexisting with renal artery stenosis is reported. Tumor resection resulted in an immediate but short-lived clinical relief. Follow-up aortography revealed progressive arterial stenosis and infrarenal aortic occlusion. Differential renal venous renin and renal scintigraphy suggested renovascular hypertension. It is necessary to search for a second curable lesion if hypertension remains uncontrollable after surgical correction of an apparent cause.
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PMID:Aldosteronoma coexisting with renal artery stenosis in secondary hypertension. 159 48

A 25-year-old female was admitted for evaluation of hypertension and hypokalemia. Plasma renin activity was suppressed and plasma aldosterone level was higher than normal. The CT scan of adrenal gland revealed a 2.5cm in size low density tumor mass over right adrenal area, and NP-59 adrenal scan showed early and persistent uptake of radioactivity in the right adrenal gland. Interestingly, the plasma aldosterone level was elevated, decreased and unchanged to postural change on three different occasions. After right adrenalectomy, the plasma aldosterone level decreased to 4.77ng/dl, blood pressure, serum potassium, and plasma aldosterone returned to normal response to postural change. Histologically, it was compatible with the picture of cortical adenoma. However, the tumor cell may not have reached autonomous function yet, since different responses of plasma aldosterone to postural change were observed clinically.
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PMID:Aldosterone-producing adenoma--variable serum aldosterone response to postural change: a case report. 165 41

The determination of plasma total renin is useful not only as a tool to investigate the physiology of hypertension but also as a marker for Wilms' tumor. A radioimmunoassay (RIA) system to determine plasma total renin was newly developed using monoclonal antibodies specific for both inactive and active renin (inactive + active = total); in this study, an effort was made to confirm that this RIA system truly determines plasma total renin concentrations. First, it was found that this monoclonal antibody stains only the juxtaglomerular apparatus of the kidney. Second, the data determined by the RIA were compared with those obtained by the conventional enzymatic method: samples were activated, and renin activity was assayed by measuring angiotensin I. The coefficient of the data obtained by this RIA system and by the conventional method was 0.921 (p less than 0.01) based on all 89 samples, and 0.809 (p less than 0.01) based on 86 of the 89 samples whose values were less than 600 pg/ml by RIA. As a result of these studies, it was concluded that the newly developed RIA system does determine total renin levels in patients' plasma.
Tumour Biol 1991
PMID:Characterization of a radioimmunoassay to determine plasma total renin. 170 91

Components of the renin-angiotensin system can be found in the vasculature, although in most cases it is unclear how much, if any, of this renin in the vasculature is locally synthesized. Over recent years, a variety of novel actions of angiotensin II have been delineated which suggest that in appropriate physiologic or pathologic circumstances vascular angiotensin II can play an important role in determining vascular structure. Moreover, angiotensin II may play a role in neoplastic growth of vascular and nonvascular tissues.
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PMID:Angiotensin and the regulation of cellular growth. Pathophysiologic implications for cardiovascular and noncardiovascular tissues. 171 Apr 67

Angiomyolipoma occurs rarely in the liver, with only 25 previous cases being reported in the English literature. The article describes two additional cases, one of which was multicentric, with results of ultrastructural and immunocytochemical studies. Many of the tumor cells contained numerous electron-dense granules, some with transverse striations like those found in melanosomes. Both tumors stained positively for S-100 protein and melanoma-specific antibody HMB-45. One case also expressed vimentin and neuron-specific enolase. Both were negative for cytokeratin, carcinoembryonic antigen, alpha-fetoprotein, desmin, muscle-specific actin, factor VIII antigen, and chromogranin. Comparison of our ultrastructural findings with those of classic renal angiomyolipoma raises the possibility that the melanosomelike structures may represent renin granules rather than melanosomes, although the latter are not excluded. Expression of HMB-45 in angiomyolipoma has important biologic and diagnostic implications, whether or not it reflects melanocytic differentiation.
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PMID:Hepatic angiomyolipoma with striated granules and positivity with melanoma--specific antibody (HMB-45): a report of two cases. 175 13


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