deamino-arginine-vasopressin and Adrenal-Cortex-Neoplasms

Because of the variability in the clinical expression of Cushing's syndrome, different biochemical tests and imaging techniques must be used for effective diagnosis and treatment. The clinical history is important to assess the general impact of hypercortisolism on organs and systems, as well as to guide suspicion toward more aggressive entities such as overt ectopic ACTH syndrome or to detect an iatrogenic etiology of Cushing's syndrome. The screening phase relies on tests that are sensitive but not specific, such as urinary free cortisol, nocturnal salivary cortisol and 1 mg dexamethasone suppression, which still require established assessment criteria. Confirmation can be obtained by repeating urinary cortisol, 2 mg/day dexamethasone suppression, both alone and combined with corticotropin releasing hormone (CRH), to exclude pseudoCushing states. ACTH dependency can be easily explored by ACTH measurements, but the differential diagnosis between pituitary and ectopic Cushing's disease is difficult and may require invasive procedures such as inferior petrosal sinus sampling. Sophisticated imaging and isotopic techniques play a significant role in locating the source of ACTH in ectopic syndromes but are not always effective. In general, biochemical and imaging tests should be combined in order to assess different mechanisms and perspectives of the syndrome. Rigorous methodology is essential to obtain accurate results, allowing a correct diagnosis and improving therapeutic performance in this devastating disease.

Topics: ACTH Syndrome, Ectopic; Adenoma; Adrenal Cortex Neoplasms; Adrenocorticotropic Hormone; Circadian Rhythm; Corticotropin-Releasing Hormone; Cushing Syndrome; Deamino Arginine Vasopressin; Dexamethasone; Diagnosis, Differential; Diagnostic Imaging; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Petrosal Sinus Sampling; Pituitary ACTH Hypersecretion; Pituitary Neoplasms; Pituitary-Adrenal System; Saliva

The diagnosis and differential diagnosis of Cushing's syndrome remains a considerable challenge in clinical endocrinology. Investigation is a two-step process, involving first diagnosis followed by differential diagnosis. Traditionally diagnosis has relied upon urinary free cortisol (UFC) collection, low-dose dexamethasone-testing, and assessment of midnight cortisol. More recently, differentiation between mild disease and pseudo-Cushing's states has been achieved using dexamethasone-suppressed corticotropin releasing hormone (CRH) and desmopressin tests. Refinements of tests used for differential diagnosis have been made including optimized response criteria for ovine and human sequence CRH tests, desmopressin tests, GHBP-testing and testing with combinations of peptides. Despite improvements in these non-invasive tests use of inferior petrosal or cavernous sinus sampling is frequently required. Imaging is guided by biochemical assessment. MRI is the investigation of choice for Cushing's disease, but is often negative. Scintigraphic investigation using radionucleotide-labeled agonists for receptors commonly expressed by neuroendocrine tumors the investigation of occult ACTH-dependent disease remains disappointing. In this review we critically analyze the tests used for this most challenging of clinical conditions.

Topics: ACTH Syndrome, Ectopic; Adenoma; Adrenal Cortex Neoplasms; Adrenocorticotropic Hormone; Animals; Arginine Vasopressin; Circadian Rhythm; Corticotropin-Releasing Hormone; Cushing Syndrome; Deamino Arginine Vasopressin; Dexamethasone; Diagnosis, Differential; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Magnetic Resonance Imaging; Oligopeptides; Petrosal Sinus Sampling; Pituitary Neoplasms; Pituitary-Adrenal System; Radiography; Radionuclide Imaging; Sheep

To assess the ability of desmopressin to differentiate between pituitary and ectopic ACTH-dependent Cushing's syndrome and to determine whether diagnostic accuracy could be improved by administering it together with human sequence CRH, we examined its effects on cortisol and ACTH secretion when given alone or in combination with CRH in patients with Cushing's syndrome of varied etiology and compared these data to the results of a standard CRH test in the same individuals. Each patient was studied on three occasions, in random order, separated by at least 48 h. At 0900 h, via an indwelling forearm cannula, 10 micrograms desmopressin, 100 micrograms CRH, or a combination of the two were given as an iv bolus; thereafter, blood was drawn every 15 min for 2 h. The responses to the individual agents were determined according to the timing and calculation criteria suggested by Nieman et al. (1993). A total of 25 patients with Cushing's syndrome were studied: 17 patients with pituitary-dependent Cushing's syndrome, Cushing's disease (CD); 5 patients with occult ectopic ACTH secretion (EC); and 3 patients with primary adrenal (ACTH-independent) Cushing's syndrome. In this series, the best discrimination among ACTH-dependent patient groups was achieved using the combined test. Using the responses of plasma cortisol, all 17 patients with CD showed a rise greater than any of the 5 patients with EC, whereas 1 patient with CD showed a plasma ACTH response within the range seen in the patients with EC. Plasma cortisol responses to desmopressin alone were seen in 14 of 17 patients with CD and 1 of 5 patients with EC and, after CRH alone, in 15 of 17 patients with CD but in no patient with EC. In contrast, plasma ACTH responses after CRH alone were seen in 14 of 17 patients with CD and 2 of 5 patients with EC and, after desmopressin alone, in 12 of 17 with CD and 3 of 5 with EC, thus indicating overlapping responses between the groups and poorer discrimination. No responses were seen in the ACTH-independent group. These data indicate that desmopressin causes the secretion of ACTH and cortisol in patients with ACTH-dependent Cushing's syndrome, and that in combination with CRH, it may provide an improvement over the standard CRH test in the differential diagnosis of ACTH-dependent Cushing's syndrome. Furthermore, these data suggest that there may be abnormalities in vasopressin receptor function or number in ACTH-secreting tumors.

Topics: ACTH Syndrome, Ectopic; Adolescent; Adrenal Cortex Neoplasms; Adrenocorticotropic Hormone; Adult; Aged; Child; Corticotropin-Releasing Hormone; Cushing Syndrome; Deamino Arginine Vasopressin; Diagnosis, Differential; Female; Humans; Hydrocortisone; Male; Middle Aged; Pituitary Neoplasms

We herein present the case of a 53-year-old patient with adrenocorticotropin-independent macronodular adrenocortical hyperplasia (AIMAH), which is a rare form of Cushing syndrome. He had hypercortisolemia and bilateral macronodular adrenal glands with a left side predominance. The administration of vasopressin significantly increased the plasma cortisol level (1.9-fold). Following left adrenalectomy, the patient's hypercortisolemia significantly improved and vasopressin responsiveness was lost, suggesting that the responsiveness originated from the resected left adrenal gland. The marked difference in vasopressin responsiveness between the adrenals corresponded with their asymmetrical size and function. Evaluating the differences in the vasopressin sensitivity may therefore be helpful for understanding the progression of AIMAH.

Topics: Adenoma; Adrenal Cortex; Adrenal Cortex Neoplasms; Adrenalectomy; Adrenocorticotropic Hormone; Cushing Syndrome; Deamino Arginine Vasopressin; Dexamethasone; Diabetes Mellitus, Type 2; Glucose Tolerance Test; Gonadotropin-Releasing Hormone; Humans; Hydrocortisone; Hypertriglyceridemia; Laparoscopy; Male; Middle Aged; Organ Size; Receptors, Vasopressin; Thyrotropin-Releasing Hormone; Vasopressins

Topics: ACTH Syndrome, Ectopic; Adrenal Cortex Neoplasms; Corticotropin-Releasing Hormone; Cushing Syndrome; Deamino Arginine Vasopressin; Diagnosis, Differential; Humans; Pituitary-Adrenal Function Tests

We assessed the ability of desmopressin to stimulate the pituitary-adrenal axis in patients with Cushing's syndrome.. The cortisol response to 5 ot 10 micrograms of intravenous desmopressin was evaluated in 31 patients with Cushing's syndrome of several aetiologies and in 15 normal subjects.. Cortisol responses were observed in 15 out of 16 patients with pituitary dependence and in two patients with adrenal nodular hyperplasia, the increase above baseline ranging from 61 to 379% in the responders. Eight patients with adrenal tumours and one with the ectopic ACTH syndrome did not respond to desmopressin, having shown changes in their cortisol levels from -5 to 42% above baseline. Responses occurred in two out of the 15 normal individuals, whose cortisol increased 58 and 69% above baseline, respectively. Stimulation tests with standard agents as lysine vasopressin or ovine corticotrophin-releasing hormone were performed in the same patients and there was a high degree of concordance. No serious adverse reactions were observed in the tests with desmopressin.. Desmopressin was able to stimulate the pituitary-adrenal axis in patients with Cushing's disease and, like corticotrophin releasing hormone, it may prove useful in the differential diagnosis of Cushing's syndrome.

Topics: ACTH Syndrome, Ectopic; Adolescent; Adrenal Cortex Neoplasms; Adult; Child; Cushing Syndrome; Deamino Arginine Vasopressin; Diagnosis, Differential; Female; Humans; Hydrocortisone; Male; Middle Aged; Pituitary-Adrenal Function Tests; Stimulation, Chemical