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At least 109 records · Page 6Linked to original sources
PubMed2006

FSH-producing macroadenoma associated in a patient with Cushing's disease.

OBJECTIVE AND IMPORTANCE: We encountered a Cushing's disease patient whose surgically removed pituitary macroadenoma was not an ACTH-producing, but rather a gonadotroph adenoma. Cure was obtained only after a tiny microadenoma, overlooked on preoperative studies, was removed by a 2nd operation from a compressed thin normal anterior pituitary gland. CLINICAL PRESENTATION: This 45-year-old woman with Cushing syndrome presented with diabetes mellitus and steroid psychosis. Endocrinological examinations suggested Cushing's disease and MRI disclosed an invasive macroadenoma (22 mm in diameter) with suprasellar extension. INTERVENTION: Despite total removal of the invasive macroadenoma by transsphenoidal surgery, her elevated serum cortisol- and ACTH levels failed to decrease. Histologic study of the surgical specimen disclosed that the tumor was a silent FSH-producing, rather than an ACTH-producing adenoma. Detailed re-evaluation of pre- and postoperative MRI suggested the presence of a 3-mm microadenoma on the left side of a thin compressed normal gland. Venous sampling of the cavernous sinus confirmed this suspicion. In a 2nd operation an ACTH-producing microadenoma was removed from inside the thin remaining compressed normal pituitary gland and endocrinological cure of Cushing's disease was achieved. CONCLUSION: Although double adenomas, being a non-ACTH producing macroadenoma associated with an ACTH producing tiny microadenoma, are extremely rare in patients with Cushing's disease, detailed preoperative MRI evaluation is necessary to avoid missing tiny adenomas hidden in a compressed normal pituitary gland which is the cause of Cushing's disease, especially when a macroadenoma is found in patient with Cushing's disease.

Adrenocorticotropic Hormone↗
PubMed2004

The role of somatostatin analogs in Cushing's disease.

Somatostatin (SRIF) has been proposed to be of therapeutic interest in the medical treatment of Cushing's disease. While in vitro data demonstrate the presence of SRIF-receptor subtype (sst) expression in corticotroph adenomas, the current clinically available SRIF-analog Octreotide, predominantly targeting sst(2), is ineffective in lowering ACTH levels in Cushing's disease and only appears to inhibit the release of ACTH in Nelson's syndrome. In the present review, current knowledge on the physiological role of SRIF in the regulation of ACTH secretion by the anterior pituitary gland, as well as by corticotroph tumor cells is summarized. In addition, the role of glucocorticoids in regulating sst-mediated inhibition of ACTH release by corticotroph adenoma cells is discussed. Recently, it was reported that the novel multiligand SRIF-analog SOM230 might have the potential to be of therapeutic interest for Cushing's disease. On the basis of the potent suppressive effects on ACTH release by SRIF-analogs with high binding affinity to sst(5) and the observation that sst(5) expression and action is relatively resistant to glucocorticoid treatment, including the recent observation that sst(5) is the predominant sst expressed in human corticotroph adenomas, it is hypothesized that sst(5) may be a new therapeutic target for the control of ACTH and cortisol hypersecretion in patients with pituitary dependent Cushing's disease.

ACTH-Secreting Pituitary Adenoma↗
PubMed2006

Glucocorticoid resistance syndrome: A diagnostic and therapeutic approach.

In the past decades, several cases of the syndrome of generalized glucocorticoid (GC) resistance have been reported. This familial disease is characterized by reduced cortisol effects, due to a GC receptor (GR) defect, which is compensated by hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. As a consequence, patients present with signs of adrenal overproduction of mineralocorticoids (hypertension and hypokalaemic alkalosis) and, in females, of androgens (hirsutism, male pattern of baldness, menstrual irregularities). In a few kindreds the underlying molecular basis has been revealed--e.g. mutations in the gene coding for the GR--but in a substantial number of patients the cause of GC resistance has not yet been elucidated. In this chapter we also discuss some other determinants which can lead to GC resistance. Diagnosis of generalized GC resistance can be difficult. This review highlights the diagnostic process and therapeutic options for treating patients with this disease.

Cushing Syndrome↗
PubMed2005

Joint synchrony of reciprocal hormonal signaling in human paradigms of both ACTH excess and cortisol depletion.

The hypothalamo-pituitary-adrenal axis is a stress-adaptive neuroendocrine ensemble, in which adrenocorticotropin (ACTH) drives cortisol secretion (feedforward) and cortisol restrains ACTH outflow (feedback). Quantifying direction- and pathway-specific adjustments within this and other interlinked systems by noninvasive means remains difficult. The present study tests the hypothesis that forward and reverse cross-approximate entropy (X-ApEn), a lag-, scale-, and model-independent measure of two-signal synchrony, would allow quantifiable discrimination of feedforward (ACTH --> cortisol) and feedback (cortisol --> ACTH) control. To this end, forward X-ApEn was defined by employing serial ACTH concentrations as a template to appraise pair-wise synchrony with cortisol secretion rates and vice versa for reverse X-ApEn. Coupled hormone profiles included normal ACTH-normal cortisol, high ACTH-high cortisol, and high ACTH-low cortisol concentrations in 35 healthy subjects, 21 patients with tumoral ACTH secretion, and 9 volunteers given placebo and a steroidogenic inhibitor, respectively. We used forward and reverse X-ApEn analyses to identify marked and equivalent losses of feedforward and feedback linkages (both P < 0.001) in patients with tumoral ACTH secretion. An identical analytical strategy revealed that ACTH --> cortisol feedforward synchrony decreases (P < 0.001), whereas cortisol --> ACTH feedback synchrony increases (P < 0.001), in response to hypocortisolemia. The collective outcomes establish precedence for pathway-specific adaptations in a major neurohormonal system. Thus quantification of directionally defined joint synchrony of biologically coupled signals offers a noninvasive strategy to dissect feedforward- and feedback-selective adaptations in an interactive axis.

Adolescent↗
PubMed2004

Effect of pioglitazone on adrenocorticotropic hormone and cortisol secretion in Cushing's disease.

The lack of an effective medical therapy for patients with Cushing's disease (CD) requires the search for new modalities of treatment. Peroxisomal proliferator-activated receptors (PPAR)-gamma are abundantly expressed in ACTH-secreting pituitary tumors. Treatment with PPARgamma agonists inhibits ACTH-secreting pituitary tumor growth, proliferation, and ACTH secretion in vitro in human and murine models and in vivo in murine corticotroph tumors. It was hypothesized that treatment with the PPARgamma agonist pioglitazone would normalize the hypothalamic-pituitary-adrenal axis of patients with CD. We evaluated the hypothalamic pituitary adrenal axis in five patients with CD in whom we measured: 1) the 24-h urine concentration of free cortisol; 2) the 24-h profile of serum cortisol and plasma ACTH; and 3) the ACTH and cortisol response to CRH stimulation. All measurements were taken at baseline and after low-dose dexamethasone treatment (0.5 mg dexamethasone every 6 h). The entire protocol was done before and after 30 d of treatment with 45 mg of daily oral pioglitazone. At baseline, before low-dose dexamethasone, all five patients had elevated 24-h urine free cortisol, elevated 24-h serum cortisol and plasma ACTH levels, and robust responses to CRH, consistent with their diagnosis of CD. There was no significant change in any of the above variables after 30 d of treatment with pioglitazone. Furthermore, there was no significant difference in the number of cortisol or ACTH spikes or in their diurnal rhythms. In summary, pioglitazone treatment (45 mg daily for 30 d) of patients with CD was not found to be effective at attenuating either ACTH or cortisol levels and does not appear to be an alternative to surgical therapy.

Adrenocorticotropic Hormone↗
PubMed2006

Cushing's disease arising from a clinically nonfunctioning pituitary adenoma.

A 49-yr-old woman with a large pituitary tumor leading to visual loss and galactorrhea- amenorrhea was submitted to transcranial pituitary surgery, when a clinically nonfunctioning pituitary adenoma was partially removed. Histopathology and immunohistochemistry confirmed the diagnosis of "non-secreting atypical adenoma." At that time, serum and urinary free cortisol were normal, with low T4 levels and hyperprolactinemia. The patient was discharged on thyroxine and bromocriptine and treated with conventional radiotherapy. Two years later, she presented high free urinary cortisol levels and a positive ACTH response to desmopressin testing on dexametasone 2 mg overnight. A pituitary biopsy confirmed aggressive growth as well as positive immunoreactivity for ACTH, p53, Ki-67, and c-erb-B2. The patient was then treated with radiosurgery on ketoconazole therapy. The overall clinical, laboratory, and pathological data suggest a transition from a clinically nonfunctioning to a hypersecreting ACTH-producing tumor. Putative mechanisms of tumor transformation and the possibility of a silent corticotropinoma evolving into clinical Cushing s syndrome are discussed.

Adenoma↗
PubMed2006

Ghrelin is produced by and directly activates corticotrope cells from adrenocorticotropin-secreting adenomas.

CONTEXT: In Cushing's disease, ACTH hypersecretion by pituitary corticotrope adenoma cells and resulting hypercortisolism is accompanied by a severely blunted GH secretory response. Interestingly, in Cushing's disease, ghrelin markedly increases plasma ACTH, whereas its stimulatory action on GH secretion is reduced. Although the reported expression of ghrelin receptors (GHS-R) in corticotrope tumors offers a potential mechanism for ghrelin-induced ACTH hypersecretion, studies on the direct effects of synthetic GH secretagogues on corticotropinoma cells offered contradictory results. OBJECTIVE AND DESIGN: To evaluate the direct action of ghrelin on corticotropinoma cells from two patients with Cushing's disease, we measured its effect on free cytosolic calcium concentration ([Ca(2+)](i)). Additionally, expression of GHS-R and its ligand ghrelin was examined in these cells and in five additional corticotropinomas. RESULTS: Ghrelin (10(-6) m) induced a marked [Ca(2+)](i) increase in 89.5% (case 1; n = 19 cells) and 85% (case 2; n = 13 cells) of corticotropinoma cells. Moreover, RT-PCR showed that expression of GHS-R isoforms is accompanied by that of ghrelin in all seven corticotrope adenomas examined. Importantly, double immunogold electron microscopy revealed that ghrelin is costored within ACTH secretory vesicles in densely granulated adenomatous corticotropes. CONCLUSIONS: These results constitute the first demonstration that ghrelin acts directly on corticotrope tumor cells derived from patients with Cushing's disease. The presence of ghrelin and GHS-R suggests that pituitary ghrelin may play an autocrine/paracrine role in regulating ACTH release in Cushing's disease. Our findings provide a plausible cellular basis for the exaggerated ACTH response to ghrelin in Cushing's disease and suggest novel research strategies to develop medical treatments for this disease.

Adenoma↗
PubMed2006

An approach to the evaluation and treatment of Cushing's disease.

Cushing's syndrome is an uncommon disorder involving dysregulation of the hypothalamic-pituitary-adrenal axis resulting in endogenous hypercortisolemia. It has multiple causes, but most commonly is due to hypersecretion of corticotropin from the pituitary gland, called Cushing's disease. The diagnosis of Cushing's syndrome remains a challenge to clinicians because routine hormonal assays can have significant overlap in pathological and normal states. We will review an approach to evaluating patients with suspected cortisol excess. We will also discuss treatment options and post-surgical assessment for those diagnosed with Cushing's disease.

Animals↗
PubMedDate not supplied

Ectopic adrenocorticotropic hormone hypersecretion due to a primary pulmonary paraganglioma.

OBJECTIVE: To present a rare case of primary paraganglioma of the lung, which caused the syndrome of ectopic adrenocorticotropic hormone (ACTH) hypersecretion. METHODS: The clinical, biochemical, and imaging findings in this case are described, and the pathologic features of the resected tumor tissue are depicted. In addition, the related literature on paragangliomas is reviewed. RESULTS: In a 39-year-old woman with hypertension, weight gain, and easy bruising, laboratory studies showed hypercortisolemia, high plasma ACTH levels, and suppression of cortisol by high-dose dexamethasone. An indium-labeled octreotide whole-body scan disclosed a tumor in the left lower lung field. Thoracoscopic wedge resection of the pulmonary mass was performed. Postoperative microscopic findings and immunohistochemical stains revealed nests of rounded and polyhedral cells and S-100 protein-positive sustentacular (supporting) cells, charac- CONCLUSION: This unusual case of Cushing's syndrome was attributable to an ACTH-secreting primary pulmonary paraganglioma.

Adrenocorticotropic Hormone↗
PubMed2006

Synapse loss from chronically elevated glucocorticoids: relationship to neuropil volume and cell number in hippocampal area CA3.

Individuals with clinical disorders associated with elevated plasma glucocorticoids, such as major depressive disorder and Cushing's syndrome, are reported to have smaller hippocampal volume. To understand how the hippocampus responds at the cellular and subcellular levels to glucocorticoids and how such changes are related to volume measures, we have undertaken a comprehensive study of glucocorticoid effects on hippocampal CA3 volume and identified elements in the neuropil including astrocytic volume and cell and synapse number and size. Male Sprague-Dawley rats were injected with corticosterone (40 mg/kg), the primary glucocorticoid in rodents, or vehicle for 60 days. The CA3 was further subdivided so that the two-thirds of CA3 (nearest the dentate gyrus) previously shown to be vulnerable to corticosterone could be analyzed as two separate subfields. Corticosterone had no effect on neuropil volume or glial volume in the proximal subfield but caused a strong tendency for astrocytic processes to make up a larger proportion of the tissue and for volume of tissue made of constituents other than glial cells (primarily neuronal processes) to be smaller in the middle subfield. Within the neuropil, there were no cellular or subcellular profiles that indicated degeneration, suggesting that corticosterone does not cause prolonged damage. Corticosterone did not reduce cell number or cell or nonperforated synapse size but did cause a pronounced loss of synapses. This loss occurred in both subfields and, therefore, was independent of volume loss. Together, the findings suggest that volume measures can underestimate corticosterone effects on neural structure.

Animals↗
PubMed2006

Polycythemia as the first manifestation of Cushing's disease.

A 39-yr-old man presented to our hospital with unexplained erythrocytosis and hypertension. His follow-up for erythrocytosis had begun 2 yr earlier in another hospital and he had been diagnosed with polycythemia rubra vera. On admission to our hospital he was hypertensive (165/95 mmHg) and, except for the presence of moon-like face and facial plethora, his physical examination was normal. His hemoglobin concentration was 19.2 g/dl, and hematocrit was 58.9% with an increased red blood cell mass of 58 ml/kg as measured by radioisotope (Cr51). Blood film, other hematological indices except for elevated leukocyte alkaline phosphatase score, arterial gas analysis, and examination of aspirated bone marrow were all normal. An abdominal ultrasonography showed no evidence of splenomegaly. A diagnosis of probable secondary erythrocytosis was made. Early-morning serum cortisol and 24-h urinary free cortisol concentration as well as serum ACTH were high. Serum cortisol was not suppressed by low-dose dexamethasone, but suppressed by high-dose dexamethasone. Pituitary magnetic resonance imaging showed no lesion. After inferior petrosal sinus sampling suggesting right-central ACTH secretion, the patient underwent transnasal-transsphenoidal pituitary adenomectomy. Both hypercortisolemia and erythrocytosis regressed completely after the adenomectomy. After the operation, the patient's hemoglobin concentration and hematocrit decreased steadily, and 1 month post-adenomectomy his hemoglobin is 14.9 g/dl and hematocrit 44.8%. Thus, Cushing's syndrome should be a routine part of evaluation of unexplained polycythemia.

Adult↗
PubMed2004

Circadian blood pressure profile in patients with Cushing's syndrome before and after treatment.

The aim of the study was to evaluate the circadian blood pressure (BP) profiles in patients with two forms of Cushing's syndrome, and to compare them to those in patients with essential hypertension. The study included 100 patients with Cushing's syndrome (80 with pituitary adenomas and 20 with adrenal adenomas) and 40 with essential hypertension. Twenty-four-h ambulatory BP monitoring was performed before and after therapy. All 3 groups had similar office-, 24-h-, awake-, and sleep BP mean values. The awake-sleep differences between the patients with two forms of Cushing's syndrome were similar. The night-time BP decline in the patients with Cushing's disease, as well as in those with adrenal adenomas, was significantly lower than that in the patients with essential hypertension. In the patients with both forms of Cushing's syndrome, there was a highly significant decline in the office and ambulatory BP levels after the treatment, and the awake-sleep systolic BP difference became significantly higher. The night-time diastolic BP decline was significantly higher after treatment in patients with adrenal adenomas and not-significantly higher in patients with Cushing's disease. In the patients with Cushing's disease, the duration of hypertension was greater, and lower percentage of normalized BP after treatment was observed in comparison with the patients with adrenal adenomas. The significant negative correlation between duration of the disease and extent of the night-time BP decline suggests that the 'non-dipping' profile is related not only to hypercortisolism itself but also to the severity of hypertension and duration of the disease.

Adenoma↗