Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0007095 (carcinoid)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 51-year-old woman with typical Cushing's syndrome of about 9 years duration was shown to have a gastric carcinoid tumor. Plasma levels of ACTH and cortisol were elevated and lacked the normal diurnal rhythm. Urinary excretion of steroids was unaffected by the administration of either metyrapone or dexamethasone. Fluctuation in urinary steroid excretion, as well as transient hypokalemic alkalosis and glycosuria suggested periodic hormonogenesis. The extirpated gastric carcinoid was shown to contain immunoreactive ACTH and beta-MSH. However, the biologic ACTH activity was undetectable by in vivo steroidogenic assay. By gel filtration, it was demonstrated that both tumor and plasma ACTH was predominately "big" ACTH. Although postoperatively she developed hypoadrenocorticism severe enough to require ACTH treatment, her pituitary-adrenal function was gradually restored. This is the first documented case of ectopic ACTH syndrome caused by gastric carcinoid in which successful cure was achieved by surgery.
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PMID:Gastric carcinoid with ectopic production of ACTH and beta-MSH. 17 2

Most patients with extra-pituitary ACTH-secreting tumors die from carcinoma, but a few can benefit from operation. Of 96 patients with Cushing's syndrome, 11 probably had such tumors. There were three modes of presentation: (1) three had malignant tumors with visceral metastases initially. One (bronchial carcinoid) died without operation. Two with carcinoma (thyroid medullary and islet-cell) underwent adrenalectomy with remission, but died soon. (2) three had apparently benign tumors initially. One (appendicular carcinoid) underwent appendectomy and one (bronchial carcinoid with hilar node metastases) underwent lobectomy. Both had rapid remissions. The third (pheochromocytoma) died after resection of the tumor. (3) five patients had no obvious tumors and underwent adrenalectomy with remission. In one a benign bronchial carcinoid was removed later. Four others remain well, but without localizing signs of tumor. The main biochemical features in all were hypokalemic alkalosis and very high urinary excretion of free cortisol. Seven of the eight patients without visceral metastases are in remission from one to 15 years after operation.
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PMID:Surgical management of the ectopic ACTH syndrome. 628 49

Cushing's syndrome is associated with hypertension in approximately 80% of cases. Hypertension contributes to the marked increased mortality risk of past or current Cushing's syndrome, largely because of increased cardiovascular risk. Observation of the pathophysiological effect of chronically elevated ACTH and cortisol values in patients with ectopic ACTH secretion complements the available data from acute studies of the effects of ACTH and glucocorticoid infusions in normal volunteers. In a retrospective case review, we identified 58 patients with Cushing's syndrome caused by ectopic ACTH secretion, who were treated at the National Institutes of Health between 1983-1997. The diagnosis of an ectopic ACTH cause was confirmed by inferior petrosal sinus sampling and/or pathologic examination of tumor. The commonest causes were bronchial carcinoid (40%) and thymic carcinoid (10%), but 18 of 58 (31%) patients had an unknown source of ectopic ACTH. Hypertension (systolic blood pressure >140 mmHg and/or diastolic blood pressure >90 mmHg in adults) was noted in 45 of 58 (78%) ectopic Cushing's patients, a prevalence similar to that noted in other endogenous Cushing's syndrome etiologies. Hypertension was severe, deemed to require 3 or more drugs by the treating physicians, in 26 of 58 (45%) patients. Hypokalemia was much more prevalent than in patients with other causes of Cushing's syndrome, affecting 33 of 58 (57%) patients. The range of plasma ACTH (17-1557 pg/mL, normal <60) and 24-hour urine cortisol (UC) excretion (192-1600 mcg/24 hr, normal <90) allowed analysis of the influence of these hormones on blood pressure and plasma potassium. There was a significant relationship between 24-hour UC excretion and the presence of hypokalemia (P = 0.003). Eight of nine patients with a UC >6000 mcg/24 hr had hypokalemia. There was no relation between ACTH level and hypokalemia. In addition, we did not find blood pressure severity to be related to UC excretion or ACTH levels. Urine and plasma cortisol and cortisol metabolite measurements suggest that cortisol may act as a mineralocorticoid when in excess, perhaps by saturating the 11beta-hydroxysteroid-dehydrogenase (11beta-HSD2 enzyme) that inactivates cortisol at the renal tubule. The current data suggest that high cortisol levels may be the principal cause of hypokalemic alkalosis in Cushing's syndrome, rather than inhibition of the 11betaHSD2 enzyme by ACTH or the effects of adrenal steroid biosynthetic intermediaries with mineralococorticoid activity.
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PMID:Association of hypertension and hypokalemia with Cushing's syndrome caused by ectopic ACTH secretion: a series of 58 cases. 1238 48