Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 49-year old woman with a 5-year history of Cushing's syndrome was evaluated. Biochemical measurements revealed high cortisol and adrenocorticotropic hormone (ACTH) levels consistent with the ACTH-dependent type of Cushing's syndrome. However, the source of ACTH seemed to be autonomous as she demonstrated abnormal feedback control, with lack of response to metyrapone and high coses of dexamethasone. A search for an ectopic ACTH-secreting nonpituitary neoplasm was unsuccessful. Transsphenoidal pituitary exploration revealed a normal pituitary gland, but an ectopic pituitary adenoma was found incidentally in the mucosa of the sphenoid sinus. This adenoma stained strongly positive for ACTH on immunocytochemical studies. Resection of this lesion led to remission of the Cushing's syndrome. This variant of ACTH-dependent Cushing's syndrome can mimic the ectopic ACTH-dependent type and should be looked for in patients who fail to respond to pituitary operation.
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PMID:Cushing's syndrome caused by an ectopic pituitary adenoma. 282 48

ACTH concentration was measured in simultaneously drawn blood samples from the left and right inferior petrosal sinuses before and after administration of corticotropin-releasing hormone (CRH). Such samples were successfully obtained in 20 of 21 patients with ACTH-dependent Cushing's syndrome on whom it was attempted. In 11 of the 20 patients there was no concentration difference between petrosal sinus and peripheral blood. But 13 of 19 patients had a unilateral central to peripheral concentration gradient greater than 1.4 after CRH administration. In the other six patients no ipsi- to contralateral gradient was demonstrable. Two of these patients had a proven ectopic ACTH-producing tumor; no adenoma was found at operation in three; on patient is awaiting operation. In 10 of 13 patients with unilateral gradient a microadenoma was found on the same side at operation. One patient had a hemi-hypophysectomy on the side of the higher gradient: hypocortisolemia developed in her postoperatively. Two other patients are awaiting operation. The results indicate that simultaneous bilateral catheterization of the inferior petrosal sinus with CRH stimulation is a highly informative examination with few side-effects and will contribute to better diagnosis and treatment of Cushing's syndrome.
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PMID:[Simultaneous bilateral catheterization of the inferior petrosal sinus in Cushing's syndrome. ACTH determination for the diagnosis and location of the side of a hypophyseal microadenoma before and after administration of corticotropin-releasing hormone]. 282 62

In recent years, cholesterol adrenal scintigraphy has been employed in the morphofunctional study of adrenal hypercorticism. Particularly in Cushing's syndrome, this noninvasive procedure can give a determinant contribution to distinguish ACTH-dependent from ACTH-independent forms. In our Institute, adrenal scintigraphy was performed in 77 patients with Cushing's syndrome diagnosed on clinical grounds confirmed by laboratory investigations and functional tests (17 with cortisol-secreting adenoma, 54 with pituitary ACTH-dependent bilateral adrenal hyperplasia, 2 with ectopic ACTH-dependent bilateral hyperplasia and 4 with bilateral nodular hyperplasia). Three distinct scintigraphic patterns have been identified. The 56 patients with ACTH-dependent Cushing's syndrome showed bilateral symmetric or slightly asymmetric visualization of the adrenal glands; in the 17 patients with ACTH-independent Cushing's syndrome the adrenal scintigraphy only visualized the gland harboring the adenoma; finally, a marked asymmetric visualization of the glands was observed in the 4 patients with adrenal nodular hyperplasia. These data confirm that adrenal scintigraphy is able to distinguish between ACTH-dependent and ACTH-independent Cushing's syndrome and reliably lateralizes adenomas when they are present. Moreover, the morphofunctional information obtained by this procedure, together with the high resolution morphological data by computerized tomography, allows to recognize the presence of bilateral nodular hyperplasia, an uncommon cause of Cushing's syndrome.
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PMID:Adrenal scintigraphy in the morphological and functional evaluation of Cushing's syndrome. 299 68

The 41-amino acid CRF fulfils all the criteria for a corticotrophin releasing factor, although considerable evidence suggests that other factors, particularly VP, also play a physiologically significant role in controlling ACTH release. Although human CRF has now been identified as a 41-residue peptide, most studies to date have used oCRF-41 in their exploration of the physiology and pathology of the hypothalamic--pituitary--adrenal axis. Low doses of oCRF-41 appear to be safe, and for specific tests of the readily-releasable pool of ACTH and related peptides 100 micrograms is a practical dose for most purposes. Although serious side-effects have only been noted at doses above 100 micrograms, it is reasonable to monitor all patients administered CRF-41 with great care, and in particular to be alert to hypotension, especially in patients with corticosteroid deficiency. There is little doubt that, in combination with the standard insulin-tolerance test, the CRF test is a useful means of diagnosing hypothalamic or portal dysfunction in patients with secondary adrenal failure. However, in the diagnosis and differential diagnosis of Cushing's syndrome, the role of the CRF test remains unclear. In normal subjects, a high basal cortisol level usually inhibits the response to CRF, such that a greatly enhanced response is suggestive of pituitary-dependent Cushing's syndrome. In patients with diagnosed ACTH-dependent Cushing's syndrome, an absent response to CRF predisposes towards an ectopic source of ACTH. However, there are exceptions in all directions, and it is uncertain whether the CRF test will prove of greater value than the traditional procedures, such as the dexamethasone suppression test. The differential diagnosis of depression and Cushing's disease may be its greatest value. In terms of treatment, there are as yet few data on the usefulness of CRF in expediting recovery of the pituitary-adrenal axis following long-term suppression, such as in patients with Cushing's syndrome treated by removal of a unilateral adenoma or trans-sphenoidal microadenomectomy. It is possible that such treatment may eventually be a useful application of CRF, although data are not yet available.
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PMID:The CRFs and their control: chemistry, physiology and clinical implications. 300 78

Primary aldosteronism, Cushing's syndrome and pheochromocytoma are the most frequent endocrine hypertensive disorders. Following biochemical confirmation of the clinical diagnosis, mainly non-invasive imaging techniques are necessary to determine the cause of the hormone excess. Diagnosis of primary aldosteronism is confirmed by analysis of aldosterone and renin in peripheral venous blood. Differentiation between adenoma and idiopathic adrenal hyperplasia usually is achieved by computed tomography and isotope scan. A reliable test for the biochemical confirmation of Cushing's syndrome is the determination of urine-free cortisol. In patients with equivocal results the dexamethasone suppression test is performed. Differential diagnosis between ACTH-dependent Cushing's syndrome (pituitary or ectopic) and primary adrenal disorders can be made by determination of plasma-ACTH and -cortisol. Non-invasive localization procedures include computed tomography of the abdomen, computed tomography or magnetic resonance imaging of the pituitary gland, sonography and isotope scan. Diagnosis of pheochromocytoma is based on elevated catecholamine levels in urine or plasma. The tumor is localized by ultrasound, computed tomography or isotope scan.
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PMID:[Rational diagnosis of endocrine forms of hypertension]. 307 51

1. Petrosal sinus sampling has been used to establish the source of adrenocorticotropin (ACTH) in ACTH-dependent Cushing's syndrome. Naloxone, an opioid antagonist, stimulates ACTH secretion, probably via release of endogenous hypothalamic corticotropin releasing hormone (CRH). 2. Three patients with hypercortisolism were studied. Two showed suppressed (> 50%) urinary-free cortisol excretion with high-dose dexamethasone treatment (2 mg every 6 h for 2 days), one did not suppress. The patients were subjected to bilateral simultaneous inferior petrosal sinus sampling (BSIPSS) with simultaneous peripheral venous (forearm) samples. Basal (unstimulated) samples were taken and naloxone (125 micrograms/kg bodyweight) was given intravenously with subsequent simultaneous sampling. Plasma ACTH was measured by radio-immunoassay (RIA). 3. All cases exhibited a marked rise in immunoreactive (IR)-ACTH levels (pmol/L) after naloxone injection, basal to peak: case 1, left 11.5-22.1, right 9.8 with no rise, peripheral 9.1-9.5; case 2, left 456-863, right 125-501, peripheral 59-82; case 3, left 12.7-13.0, right 277-431, peripheral 12.1-11.7. All results indicate pituitary Cushing's syndrome, with a central to peripheral ratio > 2.3:1. Pituitary Cushing's syndrome was confirmed on the results of trans-sphenoidal pituitary surgery in cases 1 and 3. 4. It is suggested that naloxone injection during petrosal sinus sampling in Cushing's syndrome may assist in the diagnosis of ACTH source, by enhancing ACTH release from a pituitary micro-adenoma.
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PMID:Naloxone stimulation of ACTH secretion during petrosal sinus sampling in Cushing's syndrome. 839 44

Simultaneous bilateral inferior petrosal sinus (IPS) sampling has been repeatedly proposed to be a highly specific approach for the diagnosis of Cushing's disease and 100% sensitivity in detecting autonomous pituitary ACTH secretion by an adenoma has been reported in a large series. We now report on a patient suffering from ACTH-dependent Cushing's syndrome in whom repeated bilateral IPS sampling failed to detect a central/peripheral gradient diagnostic for autonomous pituitary ACTH secretion during initial evaluation. Applying lysine vasopressin as the corticotroph secretatogue, the maximum central/peripheral gradient was 1.0 before and 1.1 following stimulation. Moreover, results of high dose dexamethasone and corticotrophin releasing hormone administration suggested ectopic ACTH secretion. Since thorough diagnostic procedures failed to localise a suspected carcinoid tumour, occult ectopic Cushing's syndrome was diagnosed. Eight years later, a pituitary macroadenoma was detected by magnetic resonance imaging (MRI), IPS catheterisation then revealed a maximal central/ peripheral gradient of 9.3 before and 20.4 after the intravenous administration of lysine vasopressin. Resected tumour tissue was classified as a typical densely granulated ACTH cell adenoma. We conclude that repeated MRI scans should be included in the follow-up of patients with a diagnosis of occult ectopic Cushing's syndrome to avoid the risk of overlooking 'occult eutopic Cushing's syndrome'.
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PMID:Occult eutopic Cushing's syndrome--failure of simultaneous bilateral petrosal sinus sampling to diagnose pituitary-dependent Cushing's syndrome. 924 5

We evaluated the usefulness of a desmopressin (DDAVP) test in the diagnosis of ACTH-dependent Cushing's syndrome. After an intravenous injection of 5 microg DDAVP, plasma ACTH levels increased to more than 200% of the basal levels in 10 of 10 patients with Cushing's disease, but remained less than 150% in all of 11 normal subjects, 3 patients with Addison's disease, 5 cases of Cushing's disease in remission, and 3 patients with ectopic ACTH syndrome. Peak levels of plasma cortisol after the DDAVP stimulation were 159 +/- 14% in the patients with Cushing's disease, and less than 150% of the basal levels in the other 5 groups. We also found a case of Cushing's disease with periodicity which responded to DDAVP only in the active stage. In vitro studies revealed that DDAVP directly stimulates ACTH release from corticotropic adenoma cells through V1b but not V2 vasopressin receptors. In conclusion, the DDAVP stimulation test, i.e., determination of plasma ACTH levels after 5 microg DDAVP injection, seems useful for discriminating Cushing's disease from normality, and may serve to facilitate the differentiation between Cushing's disease and ectopic ACTH syndrome.
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PMID:Desmopressin stimulation test for diagnosis of ACTH-dependent Cushing's syndrome. 946 24

A 32-year-old man presenting with typical features of Cushing's syndrome showed baseline cortisol and ACTH values indicating ACTH-dependent disease. Dynamic function tests (dexamethasone, corticotropin releasing hormone (CRH), desmopressin), were suggestive of paraneoplastic ectopic ACTH production. However, inferior petrosal sinus (IPS) ACTH sampling demonstrated a maximum baseline central (363 pmol/l)-peripheral (19 pmol/l) ACTH gradient of 19.1 for the right IPS, conventionally suggestive of Cushing's disease. However, again, IPS ACTH level did not increase after CRH stimulation. Magnetic resonance imaging, while showing no evidence of an intrasellar tumour, revealed an 1.5 x 1.0 cm mass in the left sphenoid sinus which was initially interpreted as most probably being a mucosal polyp. After neurosurgical removal of the tumour, transient secondary adrenal insufficiency was present. The structure and immunostaining characteristics of the tumour demonstrated an ACTH cell adenoma of the pituitary. Ectopic ACTH-secreting pituitary adenomas may cause significant difficulties in differential diagnosis, localisation and appropriate therapy. Thus, although these tumours are rare, they should be included in the list of possible causes of ACTH-dependent Cushing's syndrome.
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PMID:Cushing's syndrome due to an ectopic ACTH-secreting pituitary tumour mimicking occult paraneoplastic ectopic ACTH production. 1061 88

Prolonged exposure of every tissue in the body to an excess of cortisol produces Cushing's syndrome. Endogenous causes of Cushing's syndrome are ACTH-dependent, including Cushing's disease, ectopic ACTH-producing tumors. CRH-producing tumors, and ACTH-independent Cushing's syndrome, including cortisol-producing adrenal benign or malignant tumors, and rare micronodular adrenal hyperplasia. In Japan the incidence of ACTH-dependent Cushing's syndrome due to endogenous causes is about 60%, in which autonomous pituitary ACTH secretion is responsible for 95%, and the rest are ectopic ACTH-producing tumors. Cortisol-secreting tumors are responsible for about 40% of endogenous causes, in which benign adenoma is 90% and adrenocortical carcinoma is 10%. The first step for the diagnosis of Cushing's syndrome is to demonstrate the presence of hypercortisolism biochemically by determining 24-hour urinary free cortisol excretion and low-dose dexamethasone suppression test. The next step is to identify the precise etiologic causes. To differentiate Cushing's syndrome, the most important procedures are dynamic endocrine tests to check the integrity of hypothalamic-pituitary-adrenal function by high dose dexamethasone suppression test, CRH test arid measurement of steroid hormone profile. Imaging techniques can help to determine the etiology of Cushing's syndrome.
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PMID:Pathophysiology and diagnosis of Cushing's syndrome. 1091 6


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