Search

Purpose: To investigate the different clinical characteristics of silent corticotroph adenomas (SCAs) with positive and negative adrenocorticotropic hormone (ACTH) immunostaining, and to explore the value of pituitary-restricted transcription factor (Tpit) immunostaining for diagnosing SCAs., Methods: The clinical materials of patients with SCAs who had a typical pathological feature with positive Tpit immunostaining and positive/negative ACTH immunostaining, and without clinical features and biochemical evidence for Cushing's Syndrome in our center from April 2018 to March 2019 were analyzed retrospectively. The differences in clinical characteristics and surgical results between ACTH-positive and -negative SCAs were explored., Results: A total of one hundred and five patients (94.3% female) with SCAs were included. There were 66 SCAs with ACTH-negative (66/105, 62.9%), and 39 SCAs with ACTH-positive (39/105, 37.1%). Cases with ACTH-negative SCAs were more likely to have lower ACTH levels (27.5 ± 24.0 vs. 54.4 ± 58.6, P = 0.011), more multiple microcysts (81.8% vs. 61.5%, P = 0.022) and lower levels of Ki-67 expression (low expression rate 90.9% vs. 74.4%, P = 0.023). No statistical significant differences were observed between patients with ACTH-positive and -negative SCAs regarding gender (97.0% vs. 89.7%, P = 0.192), age (50.3 ± 10.3 vs. 49.0 ± 11.2, P = 0.543), surgical history (16.7% vs. 23.1%, P = 0.419), suprasellar extension (66.7% vs. 74.4%, P = 0.408), sphenoid sinus extension (51.5% vs. 56.4%, P = 0.627), cavernous sinus invasion (75.8% vs. 66.7%, P = 0.314), large cyst on Magnetic Resonance Imaging (MRI) (47.0% vs. 61.5%, P = 0.149), or gross total resection rate (42.4% vs. 51.3%, P = 0.379)., Conclusions: ACTH-negative SCAs were observed to be more clinically silent and more likely to demonstrate multiple microcysts on MRI. The prevalence of SCAs, especially ACTH-negative SCAs, proved to be substantially underestimated and thus they should be given enough attention in consideration of the high aggressiveness of this subtype of refractory pituitary adenoma (PA)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zhang, Shou, Chen, Qiao, He, Chen, Shen, Li, Zhao, Zhang, Li, Ye and Wang.)

Adrenocorticotropic hormone (ACTH)-secreting lung carcinoids represent the principal cause of ectopic Cushing syndrome, but the prevalence of ACTH expression and the association between ACTH production and Cushing syndrome in lung carcinoids have scarcely been investigated. In addition, available information on the prognostic meaning of ACTH production is controversial. The aims of this multicentric retrospective study, also including a review of the literature, were to describe the clinico-pathologic features of ACTH-producing lung carcinoids, to assess recurrence and specific survival rates, and to evaluate potential prognostic factors. To identify ACTH production in 254 unselected and radically resected lung carcinoids, we used a double approach including RT-PCR (mRNA encoding for pro-opiomelanocortin) and immunohistochemistry (antibodies against ACTH and β-endorphin). Sixty-three (24.8%) tumors produced ACTH and 11 of them (17.4%), representing 4.3% of the whole series, were associated with Cushing syndrome. The median follow-up time was 71 months. The 10-year overall and specific survival rates were 88.5% and 98.2%, respectively, with difference neither between functioning and nonfunctioning tumors nor between ACTH-positive and ACTH-negative carcinoids. At univariate analysis, histological type (typical or atypical) and Ki67 index significantly correlated with tumor recurrence. The literature review identified 172 previously reported patients with functioning ACTH-secreting lung carcinoids, and the meta-analysis of survival showed that 92% of them were alive after a mean follow-up time of 50 months. Our results demonstrate that ACTH-producing lung carcinoids are not rare, are not always associated with Cushing syndrome, and do not represent an aggressive variant of lung carcinoid.

Context: Cyclic Cushing syndrome is a rare variant of Cushing syndrome that demonstrates periodic cortisol excess. It has been thought that inhibition of a glucocorticoid positive-feedback loop is associated with remission of hypercortisolism in ACTH-dependent cyclic Cushing syndrome. However, the underlying mechanism that triggers the development of the hypercortisolism is still unknown. We observed a case of ACTH-dependent cyclic Cushing syndrome that was developed by exogenous glucocorticoids, possibly through a glucocorticoid positive-feedback loop., Case Description: A 75-year-old woman had experienced cyclic ACTH and cortisol elevations six times in the previous 4 years. Her diagnosis was cyclic Cushing syndrome. During the hypercortisolemic phase, neither low-dose nor high-dose dexamethasone suppressed her plasma ACTH and cortisol levels. Daily metyrapone therapy decreased her plasma cortisol and ACTH levels during every hypercortisolemic phase. After the sixth remission of a hypercortisolemic phase, she took 25 mg of hydrocortisone for 4 weeks and developed ACTH-dependent hypercortisolemia. Treatment with 1 mg of dexamethasone gradually increased both plasma ACTH and cortisol levels over 2 weeks, resulting in the eighth hypercortisolemic phase. Treatment using a combination of dexamethasone and metyrapone did not increase plasma ACTH or cortisol level and successfully prevented development of ACTH-dependent hypercortisolism., Conclusion: We present an interesting case of cyclic Cushing syndrome in which ACTH-dependent hypercortisolemic phases relapsed during exogenous glucocorticoid treatment. A glucocorticoid positive-feedback loop and endogenous glucocorticoid synthesis may play key roles in the periodicity of hypercortisolism in cyclic Cushing syndrome., (Copyright © 2019 Endocrine Society.)

Background: Cushing's syndrome in humans shares many similarities with its counterpart in dogs in terms of etiology (pituitary versus adrenal causes), clinical signs, and pathophysiologic sequelae. In both species, treatment of pituitary- and adrenal-dependent disease is met with limitations. ATR-101, a selective inhibitor of ACAT1 (acyl coenzyme A:cholesterol acyltransferase 1), is a novel small molecule therapeutic currently in clinical development for the treatment of adrenocortical carcinoma, congenital adrenal hyperplasia, and Cushing's syndrome in humans. Previous studies in healthy dogs have shown that ATR-101 treatment led to rapid, dose-dependent decreases in adrenocorticotropic hormone (ACTH) stimulated cortisol levels. The purpose of this clinical study was to investigate the effects of ATR-101 in dogs with Cushing's syndrome., Methods: ATR-101 pharmacokinetics and activity were assessed in 10 dogs with naturally-occurring Cushing's syndrome, including 7 dogs with pituitary-dependent disease and 3 dogs with adrenal-dependent disease. ATR-101 was administered at 3 mg/kg PO once daily for one week, followed by 30 mg/kg PO once daily for one (n = 4) or three (n = 6) weeks. Clinical, biochemical, adrenal hormonal, and pharmacokinetic data were obtained weekly for study duration., Results: ATR-101 exposure increased with increasing dose. ACTH-stimulated cortisol concentrations, the primary endpoint for the study, were significantly decreased with responders (9 of 10 dogs) experiencing a mean ± standard deviation reduction in cortisol levels of 50 ± 17% at study completion. Decreases in pre-ACTH-stimulated cortisol concentrations were observed in some dogs although overall changes in pre-ACTH cortisol concentrations were not significant. The compound was well-tolerated and no serious drug-related adverse effects were reported., Conclusions: This study highlights the potential utility of naturally occurring canine Cushing's syndrome as a model for human disease and provides proof of concept for ATR-101 as a novel agent for the treatment of endocrine disorders like Cushing's syndrome in humans.

Background: Adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome (CS) with bilateral cortisol-secreting adenomas has been rarely reported in the literatures. Precise recognition and management of this disorder constitute a challenge to clinicians due to the difficulty of exact location of the functional lesions., Case Presentation: We herein report a new case of a Chinese female patient with a complaint of exertional dyspnea for over 10 years. ACTH-independent CS was diagnosed based on undetectable ACTH and unsuppressed cortisol levels by dexamethasone. Computed tomography (CT) scan indicated bilateral adrenal masses, and adrenal venous sampling (AVS) adjusted by plasma aldosterone revealed hypersecretion of cortisol from both adrenal glands. Bilateral cortisol-secreting adrenal adenomas were suspected and confirmed by the postoperative pathology in subsequent two-step bilateral laparoscopic adrenalectomy. The symptoms and signs of CS relieved after surgery with continuous glucocorticoid replacement., Conclusions: AVS adjusted by plasma aldosterone could be a useful technique in diagnosing ACTH-independent CS with bilateral adrenal adenomas prior to surgery. And the aldosterone ratio could be used to confirm the success of adrenal vein cannulation in this situation.

Objective To investigate the effects of Cushing's disease (CD) and adrenal-dependent Cushing's syndrome (ACS) on bone mineral density (BMD) and bone metabolism. Methods Data were retrospectively collected for 55 patients with hypercortisolism (CD, n = 34; ACS n = 21) from January 1997 to June 2014. BMD was examined in all patients, and bone turnover markers were tested in some patients. Healthy controls (n = 18) were also recruited. Results The lumbar spine and femoral neck BMD were significantly lower in the ACS and CD groups than in the control group. Lumbar BMD was significantly lower in the ACS than CD group. The collagen breakdown product (CTX) concentrations were significantly higher while the osteocalcin and procollagen type I N-terminal propeptide (PINP) concentrations were significantly lower in the ACS and CD groups than in the control group. The PINP concentration was significantly lower while the CTX concentration was significantly higher in the ACS than CD group. In the CD group only, lumbar BMD and serum adrenocorticotropic hormone had a significant positive correlation. Conclusions Bone turnover markers indicated suppressed osteoblast and enhanced osteoclast activities. PINP and CTX changes might indicate bone mass deterioration. Adrenocorticotropic hormone might be protective for lumbar BMD in patients with CD.

Cushing's syndrome (CS) due to a corticotropin-releasing hormone (CRH) and adrenocorticotropin hormone (ACTH) co-secreting tumor is very rare, and diagnosis can be difficult. We describe a case of CS caused by ectopic CRH and ACTH production from a pancreatic neuroendocrine tumor (pNET) and discuss possible pitfalls in the diagnosis. A 48-year-old woman presented with gradual increase in body weight, muscle weakness, and difficult to control hypertension. Laboratory and imaging investigations revealed ACTH-dependent hypercortisolemia and a 3-cm mass at the head of the pancreas. The patient underwent partial pancreatoduodenectomy. Histological examination revealed a well-differentiated pNET, expressing both CRH and ACTH. After a follow-up period of 18 months, she remains asymptomatic with no metastatic disease. This is the fourth case report of CS in adults due to an ectopic ACTH- and CRH-secreting pNET. Co-secretion of ACTH and CRH by the same tumor may cause diagnostic problems since investigation depends on which of the two hormones is secreted in greater amounts. Measurement of plasma CRH may help in establishing the diagnosis, especially in patients in whom endocrine tests are indicative of ectopic CS, whereas imaging findings are suggestive of pituitary hyperplasia.

The primary bilateral macronodular adrenal hyperplasia or the independent adrenocorticotropic hormone bilateral nodular adrenal hyperplasia is a rare cause hypercortisolism, its diagnosis is challenging and there is no clear way to decide the best therapeutic approach. Adrenal venous sampling is commonly used to distinguish the source of hormonal production in patients with primary hyperaldosteronism. It could be a useful tool in this context because it might provide information to guide the treatment. We report the case of a patient with ACTH independent Cushing syndrome in whom the use of adrenal venous sampling with some modifications radically modified the treatment and allowed the diagnosis of a macronodular adrenal hyperplasia.

Although Cushing's syndrome has been described in association with various neuroendocrine tumors producing ectopic adrenocorticotropin (ACTH), primary ovarian carcinoma rarely causes this syndrome. We hereby report the case of a 61-year-old woman presented with abdominal distension, facial swelling and skin pigmentation. Clinical and diagnostic evaluation revealed a right ovarian tumor with hypercortisolemia, high plasma ACTH, extremely high plasma ACTH precursors and lack of dexamethasone suppression. Removal of the tumor led to normalization of ACTH, ACTH precursors and cortisol levels. In addition, hypokalemia, hyperglycemia and elevated serum CA 125 were noted, which were also normalized after resection of the tumor. Histopathological examination indicated a primary ovarian carcinoma with a mixed pattern of differentiation. Immunohistochemistry showed immunoreactivity for chromogranin A, synaptophysin and ACTH. Hence, the diagnosis of Cushing's syndrome arising from an ovarian carcinoma secreting ectopic ACTH was made. The case was managed successfully, with subsequent good recovery and no evidence of recurrence at 4 years of follow-up.

Background: Bilateral macronodular adrenal hyperplasia is a rare cause of primary adrenal Cushing's syndrome. In this form of hyperplasia, hypersecretion of cortisol suppresses the release of corticotropin by pituitary corticotrophs, which results in low plasma corticotropin levels. Thus, the disease has been termed corticotropin-independent macronodular adrenal hyperplasia. We examined the abnormal production of corticotropin in these hyperplastic adrenal glands., Methods: We obtained specimens of hyperplastic macronodular adrenal tissue from 30 patients with primary adrenal disease. The corticotropin precursor proopiomelanocortin and corticotropin expression were assessed by means of a polymerase-chain-reaction assay and immunohistochemical analysis. The production of corticotropin and cortisol was assessed in 11 specimens with the use of incubated explants and cell cultures coupled with hormone assays. Corticotropin levels were measured in adrenal and peripheral venous blood samples from 2 patients., Results: The expression of proopiomelanocortin messenger RNA (mRNA) was detected in all samples of hyperplastic adrenal tissue. Corticotropin was detected in steroidogenic cells arranged in clusters that were disseminated throughout the adrenal specimens. Adrenal corticotropin levels were higher in adrenal venous blood samples than in peripheral venous samples, a finding that was consistent with local production of the peptide within the hyperplastic adrenals. The release of adrenal corticotropin was stimulated by ligands of aberrant membrane receptors but not by corticotropin-releasing hormone or dexamethasone. A semiquantitative score for corticotropin immunostaining in the samples correlated with basal plasma cortisol levels. Corticotropin-receptor antagonists significantly inhibited in vitro cortisol secretion., Conclusions: Cortisol secretion by the adrenals in patients with macronodular hyperplasia and Cushing's syndrome appears to be regulated by corticotropin, which is produced by a subpopulation of steroidogenic cells in the hyperplastic adrenals. Thus, the hypercortisolism associated with bilateral macronodular adrenal hyperplasia appears to be corticotropin-dependent. (Funded by the Agence Nationale de la Recherche and others.).

We describe a rare case of ectopic Cushing's syndrome that recurred 6 years after resection of a thymic neuroendocrine carcinoma. We discuss reasons for the differing clinical presentations, management, hormone profiles, as well as immunopathology. A 41-year-old male developed acute-onset Cushing's syndrome. Clinical presentation and laboratory results were compatible with ectopic adrenocorticotropin hormone (ACTH) production. Computerized tomography (CT) showed a 3.6 cm thymic tumor which was successfully resected. Plasma ACTH (P-ACTH) normalized the first postoperative day. Histopathology demonstrated a well-differentiated neuroendocrine carcinoma with diffuse positivity for ACTH and focal corticotropin-releasing hormone (CRH) reactivity in a few scattered cells. The patient was in remission for 6 years. He then again presented with acute-onset Cushing's syndrome. Fluorine-labeled dihydroxyphenylalanine ((18)F-DOPA) PET/CT showed local uptake in the mediastinum and he underwent repeat resection. However, P-ACTH remained increased (613 ng/l) and 24-h urinary cortisol was 36,720 nmol, suggesting incomplete tumor removal or metastatic spread. Metyrapone treatment was initiated but then withdrawn because the patient spontaneously recovered and cortisol metabolism gradually normalized within 3 weeks. Histopathology demonstrated a recurrent neuroendocrine carcinoma with the same features as the previous lesion but this time CRH was strongly positive in more numerous cells. Normalization of P-ACTH after primary surgery was compatible with ectopic ACTH production. However, the delayed fall in P-ACTH and serum cortisol is compatible with ectopic CRH production and stimulation of pituitary ACTH secretion, which gradually resolved. Although ectopic CRH production is very rare, the unusual dynamics illustrated here should raise the possibility of CRH production by a neuroendocrine tumor.

Pheochromocytoma (PCC) is a challenging and life-threatening neoplasm. Herein, the authors report an interesting and unexpected solution for a clinical case concerning a patient with a PCC, who developed delayed ectopic adrenocorticotropic hormone Cushing syndrome originating from the PCC. In addition, after a misleading I-labeled metaiodobenzylguanidine single-photon emission computed tomography/computed tomography, an F-fluorodeoxyglucose positron emission tomography/computed tomography, executed to confirm the diagnosis of PCC, showed a silent pulmonary nodule that unexpectedly turned out to be a lung nocardiasis.

Background: The measurement of adrenal gland size on computed tomography (CT) scan has been proposed for the etiological diagnosis of hyperadrenocorticism (HAC) in dogs. Symmetric adrenal glands are considered to provide evidence for ACTH-dependent hyperadrenocorticism (ADHAC), whereas asymmetry suggests ACTH-independent hyperadrenocorticism (AIHAC). However, there are currently no validated criteria for such differentiation., Objective: The aim of this retrospective study was to compare various adrenal CT scan measurements and the derived ratios in ADHAC and AIHAC cases, and to validate criteria for distinguishing between these conditions in a large cohort of dogs., Animals: Sixty-four dogs with HAC (46 ADHAC, 18 AIHAC)., Methods: Dogs with confirmed HAC and unequivocal characterization of its origin were included. Linear measurements of adrenal glands were made on both cross-sectional and reformatted images., Results: An overlap was systematically observed between the AIHAC and ADHAC groups for all measurements tested. Overlaps also were observed for ratios tested. For the maximum adrenal diameter ratio derived from reformatted images (rADR), only 1/18 AIHAC dogs had a rADR within the range for ADHAC. For a threshold of 2.08, the 95% confidence intervals for estimated sensitivity and specificity extended from 0.815 to 1.000 and from 0.885 to 0.999, respectively, for AIHAC diagnosis., Conclusion and Clinical Importance: Measurements from cross-sectional or reformatted CT scans are of little use for determining the origin of HAC. However, rADR appears to distinguish accurately between ADHAC and AIHAC, with a rADR > 2.08 highly suggestive of AIHAC., (Copyright © 2011 by the American College of Veterinary Internal Medicine.)

Ectopic adrenocorticotrophic hormone (ACTH) secretion is a rare cause of Cushing syndrome in paediatric age, due to tumours arising from different tissues. To date, only 11 reports of ACTH-secreting pancreatic tumours in children and adolescents exist in the literature. We present a paediatric case of Cushing syndrome caused by ectopic ACTH secretion. This was caused by a large acinar cell carcinoma that developed in the pancreas of a 3-year-old girl.

A 66-year-old man with Cushing's syndrome due to adrenocorticotropin-independent bilateral macronodular adrenocortical hyperplasia (AIMAH) was treated for 7 years with trilostane, a 3β-hydroxysteroid dehydrogenase inhibitor. Administration of trilostane reduced the serum cortisol level to around the upper limit of normal for 7 years, and symptoms of excessive glucocorticoid production (such as moon face and obesity) were gradually improved. On the other hand, the size of both adrenal glands gradually increased despite treatment with trilostane. Though trilostane therapy could not prevent adrenal growth, it did suppress cortisol secretion over the long term, so it might be a reasonable option for AIMAH in addition to adrenalectomy.

Adrenocorticotropin (ACTH) independent bilateral macronodular adrenal hyperplasia (AIMAH) is a rare cause of Cushing's syndrome, characterized by bilateral adrenal lesions and excess cortisol production despite ACTH suppression. Cortisol synthesis is produced in response to abnormal activation of G-protein-coupled receptors, such as gastric inhibitory peptide, vasopressin, beta adrenergic agonists, LH/hCG and serotonin receptors. The aim of this study was to analyze the expression of glucagon receptors in adrenal glands from an AIMAH patient. A patient with ACTH-independent Cushing's syndrome and bilateral macronodular adrenal hyperplasia was screened for altered activation of adrenal receptors by physiological (mixed meal) and pharmacological (gonadotrophin releasing hormone, ACTH and glucagon) tests. The results showed abnormally high levels of serum cortisol after stimulation with glucagon. Hypercortisolism was successfully managed with ketoconazole treatment. Interestingly, a 4-month treatment with a somatostatin analogue (octreotide) was also able to reduce cortisol secretion. Finally, Cushing's syndrome was cured after bilateral adrenalectomy. Abnormal mRNA expression for glucagon receptor in the patient's adrenal glands was observed by Real-Time PCR procedure. These results strongly suggest that the mechanism of AIMAH causing Cushing's syndrome in this case involves the illicit activation of adrenal glucagon receptors. This is the first case reported of AIMAH associated with ectopic glucagon receptors.

Classical tests for diagnosis of Cushing's syndrome (CS) like urine free cortisol and dexamethasone suppression tests have limitations in various clinical settings. This study evaluated the usefulness of sleeping midnight serum cortisol (SMNC) as a diagnostic test for hypercortisolemia. A simultaneously done midnight plasma ACTH level was used to classify the disease as ACTH dependent or independent. Standard biochemical tests, SMNC, midnight plasma ACTH and appropriate imaging evaluated patients with a clinical suspicion of Cushing's syndrome. We evaluated 43 patients with CS comprising of 34 patients with Cushing's disease (CD), 2 patients with thymic carcinoid producing ectopic CS, 5 patients with adrenal carcinoma and 2 with adrenal adenoma. Thirteen patients with clinical suspicion were also evaluated with the above tests and CS was ruled out. SMNC, midnight plasma ACTH and dexamethasone suppressed cortisol was collected from patients with a suspicion of CS. SMNC was evaluated against histopathology as the gold standard. SMNC achieved 100% sensitivity in the diagnosis of endogenous CS at cut offs of 138 nmol/l and below. Raising the cut off to 207 nmol/l resulted in a test sensitivity of 90.5%. At a cut off of 1.65 pmol/l, midnight plasma ACTH could distinguish ACTH independent causes of CS with 100% sensitivity. We concluded that a single midnight collection could identify all patients with CS and classify the ACTH status at the proposed cut offs.

Differential diagnosis of ACTH-dependent Cushing's syndrome often presents major difficulties. Diagnostic troubles are increased by suboptimal specificity of endocrine tests, the rarity of ectopic ACTH secretion and the frequent incidental discovery of pituitary adenomas. A 43-year-old female reported with mild signs and symptoms of hypercortisolism, and initial hormonal tests and results of pituitary imaging (7-mm adenoma) were suggestive for Cushing's disease. However, inadequate response to corticotrophin-releasing hormone and failure to suppress after 8 mg dexamethasone pointed towards an ectopic source. Total body CT scan visualized only a small, non-specific nodule in the right posterior costophrenic excavation. Inferior petrosal sinus sampling revealed an absent center:periphery ACTH gradient but octreoscan and (18)F-FDG-PET-CT failed to detect abnormal tracer accumulation. We weighed results of the laboratory with those of imaging and decided to remove the lung nodule. Pathology identified a typical, ACTH-staining carcinoid and the diagnosis was confirmed by postsurgical hypoadrenalism. In conclusion, imaging may prove unsatisfactory or even misleading for the etiologial diagnosis of ACTH-dependent Cushing's syndrome and should therefore be interpreted only in context with results of hormonal dynamic testing.

Ectopic adrenocorticotropin (ACTH) secretion accounts for less than 10% of all causes of endogenous Cushing's syndrome (CS) and is usually associated with neuroendocrine tumors and small cell carcinoma of the lung. We report the case of a 62-year-old man with CS due to ectopic ACTH production by small cell carcinoma of the prostate. He presented with severe hypercortisolism and associated symptoms. Plasma neuron specific enolase (NSE) was grossly elevated. Despite performing a laparoscopic bilateral adrenalectomy, the patient died as a result of sepsis with multi-organ failure. Post-mortem immunohistochemical staining of prostate tumor tissue showed ACTH expression. ACTH staining was also performed in four additional patients with small cell carcinoma of the urinary tract without CS. None of these additional cases showed a positive staining for ACTH. Although a rare cause of ectopic ACTH production, neuroendocrine prostate carcinoma should be considered in male patients with Cushing's syndrome, in particular in those with an occult source of ACTH overproduction.

Objectives: The aim of the study was to evaluate the ACTH-immunopositive pituitary adenomas, especially those without manifestation of Cushing's disease, Material and Methods: 148 pituitary adenomas removed surgically in years 1994--2007 were studied. The paraffin sections were immunostained with antibodies against the pituitary hormones. In 79 adenomas the immunostaining with anti-ACTH antibody was performed Additionally, 23 tumors were also immunostained with anti-Ki-67 (MIB-1) antibody. Visualization of reactions was done by means of streptavidin-biotin-peroxidase technique with use of 3,3'-diaminobenzidine as chromogen., Results: ACTH immunopositivity was found in 34 cases (23%). Fourteen ACTH-immunopositive tumors manifested themselves as Cushing's disease (including 1 case of Nelson's syndrome). In the remaining 20 cases in spite of the positive immunostaining for ACTH of the tumor cells, no features of hypercortisolism were observed (in several cases even hypocortisolism was found). Thus, those tumors represented so-called "silent" corticotropinomas. Over one third (37%) of "clinically" nonfunctioning pituitary adenomas, when immunostained with anti-ACTH antibody, showed ACTH immunopositivity. Three adenomas in patients with Cushing's disease (21.4%) and 7 "silent" corticotropinomas (35%) were recurrent tumors. In contrast, the recurrence rate in the group of ACTH-immunonegative clinically nonfunctioning pituitary adenomas was 14.7%. The "silent" corticotropinomas exhibited a tendency towards the higher expression of a proliferation marker, Ki-67 antigen as compared to the "active" corticotropinomas., Conclusions: (i) "Silent" corticotropinomas are rather frequent. (ii) This adenoma type should be considered as aggressive. (iii) It is hypothetized that--like in Nelson's syndrome--the lack of hypercortisolism or even presence of hypocortisolism favorizes the exaggerated growth of tumoral corticotrophs.

A 13-year-old neutered male European short-hair cat was presented because of blindness and behavioural abnormalities. On physical examination, abnormal behaviour, compulsive walking, circling, continuous vocalization and blindness were the main neurological signs. In addition, abdominal alopecia, thin and inelastic skin, weight loss despite polyphagia, polyuria and polydipsia were present. Laboratory investigation revealed diabetes mellitus and pituitary-dependent hypercortisolism. Diagnostic imaging showed bilaterally enlarged adrenals and a large pituitary mass. Histopathological and immunohistochemical examination confirmed the clinical diagnosis of an ACTH-producing pituitary macroadenoma.

The effect of corticotropin and inhibitor of protein kinase C, chelerythrine chloride, on the change of caspase-3 level and on the rate of DNA laddering in hyperplasia adrenal cortex tissue of patient with Cushing's syndrome was studied. It was established that ACTH caused significant antiapoptotic effect in the human adrenal cortex. The adding of ACTH to incubation medium caused a sharp decrease of the caspase-3 level in adrenocorticocytes. Chelerythrine chloride, on the contrary, increases the caspase-3 level by 22%. ACTH influence decreases DNA laddering. Either the adding of chelerythrine chloride to incubation medium, or the adding of chelerythrine chloride simultaneously with ACTH, led to the enhancing of DNA fragmentation. The obtained data suggest that antiapoptotic effect of ACTH in adrenal cortex tissue estimated according by the caspase-3 level and by the rate of DNA fragmentation depends on activation of protein kinase C. However, the intensification of DNA laddering can be also explained by cytotoxic effect, high level of interaction with DNA and strong intercalation ability of this alkaloid.

Ectopic Cushing's syndrome due to various malignancies is not uncommon. However, a few cases of ectopic Cushing's syndrome caused by corticotropin-releasing hormone (CRH), or CRH with adrenocorticotropic hormone (ACTH) have been reported. A 28-year-old woman presented with acute upper gastrointestinal bleeding caused by an active ulcer, located atypically in the 2nd portion of duodenum. Further work-up revealed high gastrin levels and abdominal computed tomography (CT) scans showed a large pancreatic head mass with multiple liver metastases. The serum cortisol and ACTH levels were checked due to hypokalemia with metabolic alkalosis and recent amenorrhea. Cortisol and ACTH were both highly elevated with pituitary hyperplasia and elevated CRH. The existence of ectopic ACTH and CRH in the liver biopsy was also demonstrated immunohistochemically. Since an operation was not feasible, chemotherapy was conducted using paclitaxel and etoposide. These two drugs were chosen according to the IN VITRO chemotherapy response assay to maximize the treatment. This report demonstrates concurrent ACTH- and CRH-related ectopic Cushing's syndrome caused by malignant gastrinoma with multiple liver metastases that was treated with marginal success using a multidisciplinary medical approach.

We describe a case of adrenocortical adenoma with preclinical Cushing's syndrome demonstrating diurnal rhythms of ACTH and cortisol in blood. A 50-year-old man was admitted to the hospital for the evaluation of incidental right adrenal mass with hyperglycemia and hypertension. On admission, there were no signs of clinical manifestation of hypercortisolism. The basal levels of cortisol (9.3 microg/dl) and ACTH (9.4 pg/ml) at 0800 h were not elevated and these diurnal rhythms were maintained. One or 8 mg of dexamethasone given orally overnight suppressed the plasma ACTH but not serum cortisol. Ultrasonogram, CT and scintiscan of (131)I adosterol all demonstrated an enlarged adrenal mass in the right adrenal gland. The right adrenal gland was subsequently resected by laparoscopic surgery. Histopathological findings of resected adrenal tumor were consistent with adrenocortical adenoma. Adjacent non-neoplastic adrenal tissue demonstrated adrenocortical atrophy but DHEA-sulfotransferase immunoreactivity in the zona reticularis was detected.

Gangliocytic paraganglioma (GP) is an unusual tumor in the wide spectrum of neuroendocrine neoplasms. The biologic behavior and histogenesis of this tumor is uncertain because, despite its benign histologic features, there have been reports of metastases to regional lymph nodes and distant metastases. Although most of these tumors have been reported in the duodenum, examples of GP arising in extra-ampullary sites have been well documented. Herein, we report the case of a lung GP corticotropin producing and presenting as Cushing's syndrome. After removal of the tumor, there was a significant drop in cortisol and corticotropin levels. To our knowledge, this is the first report of a GP causing Cushing's syndrome.

Cushing's syndrome results from sustained pathologic hypercortisolism caused by excessive corticotropin (ACTH) secretion by tumors in the pituitary gland (Cushing's disease, 70%) or elsewhere (15%), or by ACTH-independent cortisol secretion from adrenal tumors (15%). The clinical features are variable, and no single pattern is seen in all patients. Those features most specific for Cushing's syndrome include abnormal fat distribution, particularly in the supraclavicular and temporal fossae, proximal muscle weakness, wide purple striae, and decreased linear growth with continued weight gain in a child. Patients with characteristics of glucocorticoid excess should be screened with measurements of saliva or urine cortisol or dexamethasone suppression testing. The diagnosis of Cushing's syndrome should be followed by the measurement of plasma ACTH concentration to determine whether the hypercortisolism is ACTH-independent. In ACTH-dependent patients, bilateral inferior petrosal sinus sampling with measurement of ACTH before and after administration of ACTH-releasing hormone most accurately distinguishes pituitary from ectopic ACTH secretion. Surgical resection of tumor is the optimal treatment for all forms of Cushing's syndrome; bilateral adrenalectomy, medical treatment, or radiotherapy are sought in inoperable or recurrent cases. The medical treatment of choice is ketoconazole. The prognosis is better for Cushing's disease and benign adrenal causes of Cushing's syndrome than adrenocortical cancer and malignant ACTH-producing tumors.

Adrenocorticotroph cell pituitary adenomas immunoreactive for adrenocorticotropic hormone (ACTH) but unassociated with preoperative signs of hypercortisolism constitute between 6% and 43% of all ACTH adenomas. Few large series have been published. At our referral center for pituitary diseases, we have encountered 12 patients with silent ACTH adenomas, none of whom exhibited definite clinical features of hypercortisolism preoperatively. Two patients presented with apoplexy, and in 2 patients preoperative neuroimaging studies mimicked craniopharyngioma. Pathological examination revealed 8 adenomas with variably basophilic cytoplasm (type I, including 1 each with coarse basophilic granules and Crooke's hyaline change) and 4 with predominantly chromophobic cytoplasm (type II). Diffuse versus patchy (30% to 50% of cells) immunostaining best distinguished these 2 types; calcitonin staining was focal or negative in both. Two patients had unexpected postoperative courses consistent with acute cortisol insufficiency; 1 patient suffered from a severe flu-like illness, and the other had dizziness and was found to have a serum cortisol level of < 1.0 microg/dL. Both patients improved after cortisol replacement followed by a slow taper. Another patient developed 2 separate pituitary adenomas, a silent ACTH adenoma followed by a pure prolactinoma resected months later. Clonality studies demonstrated that the 2 tumors had arisen from different clonal populations. These cases offer additional insights into clinical, neuroimaging, histological, and biological features of silent ACTH adenomas. Because 2 of these patients seemed to require postoperative cortisol supplementation that otherwise would not have been given, clinicians should be notified about ACTH immunostaining in adenomas from patients without preoperative diagnoses of Cushing's disease, to optimize postoperative care.

Adrenochromaffin cells have been shown to physiologically synthesize and secrete ACTH. We have thus hypothesized that excessive intraadrenal ACTH production may be involved in the pathogenesis of primary adrenal Cushing's syndrome. In this report we describe a case of Cushing's syndrome due to bilateral adrenocortical macronodular hyperplasia associated with suppression of plasma ACTH levels. HPLC analysis of adrenal tissue extracts revealed the presence of a peptide coeluting with bioactive ACTH. Immunohistochemical studies showed that ACTH immunoreactivity was detectable in a subpopulation of steroidogenic cells, but not in chromaffin cells. ACTH-positive cells were also labeled by antibodies against relaxin-like factor, a marker of Leydig cells. The presence of ACTH in the hyperplastic tissue resulted from local expression of the gene encoding the ACTH precursor proopiomelanocortin. Finally, hyperplasia fragments, contrary to normal adrenal cortex explants, appeared to release in vitro measurable amounts of ACTH. In conclusion, this observation shows that Cushing's syndromes associated with suppressed plasma ACTH levels may be dependent upon ACTH produced within adrenocortical tissue. The term ACTH-independent used to designate primary adrenal Cushing's syndrome may therefore be inappropriate in some cases of bilateral macronodular adrenal hyperplasia with hypercortisolism and undetectable plasma ACTH levels.

Background: While venous sampling for adrenocorticotropic hormone (ACTH) may be the most accurate way to establish a diagnosis of Cushing's disease, its usefulness for lateralization of adenomas is limited even in combination with simultaneous bilateral sampling methods. Therefore, to increase accuracy in predicting the lateralization of adenomas, we performed a trial in which we carried out simultaneous venous sampling from multiple sites of the cavernous sinus (CS) and inferior petrosal sinus (IPS). Here we report on the usefulness of our method in the correct tumor lateralization in patients with Cushing's disease., Methods: Eighteen patients with Cushing's disease underwent simultaneous bilateral ACTH sampling. The samples were obtained from the anterior, middle, and posterior CS and the IPS. CS sampling after stimulation with corticotropin-releasing hormone (CRH) was also performed. The central-to-peripheral ACTH ratio (c/p ratio) was calculated using sampling data from each site; the lateralizing gradients (right versus left) were calculated using the c/p ratio. Instead of the conventional method where the lateralization gradient is based on sampling data from a single site, we used the distribution of the c/p ratio determined from multiple-site data., Results: There was no significant difference in the mean lateralization gradient obtained from each set of sampling data (p > 0.05). With the conventional method, correct tumor lateralization was obtained in 50% of tumors in the IPS; 72.2 to 77.8% of tumors in the CS; and 77.8% of tumors in the middle CS after CRH. Our method using ACTH contour analysis based on multiple sites produced correct results in all 18 of the patients examined. The difference in correct calls between the conventional method and our method was significant (p < 0.05)., Conclusions: Multiple-site sampling of ACTH is valuable for lateralizing the adenoma in patients with Cushing's disease; it produces more correct results than does single venous sampling.

A 53-year-old Japanese woman was diagnosed with Cushing's disease caused by a adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma on the basis of clinical an imaging data. The surgically resected tumor tissue was investigated histopathologically using immunohistochemical analysis of pituitary hormones. Our study revealed that the adenoma expressed not only ACTH but growth hormone (GH) in the tumor cells. Furthermore, immunohistochemical double staining showed that some adenoma cells were positive for both ACTH and GH. In situ hybridization for GH mRNA revealed that the adenoma cells produced GH as opposed to simply storing it. Although many pituitary adenomas produce multiple pituitary hormones, pituitary adenoma producing both ACTH and GH in the same adenoma cells, such as seen in this case, is extremely rare. To elucidate the molecular mechanism involved, we investigated the expression of transcription factors NeuroD1 and Pit-1 and found that both transcription factors were expressed in many tumor cells. This case report describes a very rare case of pituitary adenoma that produced both ACTH and GH. We propose a hitherto undescribed translineage expression of transcription factors as the basic mechanism of this unique functional differentiation.

This report describes a rare case of ACTH-independent macronodular adrenal hyperplasia (AIMAH) arisen with symptomatic severe hypertension and hypokaliemia. A 55-year-old man was admitted to hospital with a clinical picture characterized by several episodes of transient ischemic attacks (TIA) and right hemiplegia, related to severe arterial hypertension. Laboratory tests showed urinary levels of catecholamines, metanephrines and vanillylmandelic acid (VMA) in normal range; high urinary free cortisol excretion, elevated serum cortisol with loss of the circadian rhythm and low ACTH plasma levels. ACTH failed to respond to CRH administration. Serum cortisol levels were not modified after high doses of dexamethasone. MRI showed bilateral macronodular hyperplasia of adrenal glands, whereas pituitary-MRI did not show tumoral lesions. Therefore, ACTH-independent macronodular hyperplasia was suspected. Though obese, the patient had no typical Cushing habit, and symptomatic hypertension with hypokaliemia was the only clinical evidence for this rare kind of Cushing's syndrome. After obtaining a satisfactory control of blood pressure, the patient was successfully submitted to laparoscopic bilateral adrenalectomy and underwent complete clinical remission. The histology showed adrenal macronodular hyperplasia. During the twenty-four month follow-up, the patient had no further transient ischemic attacks or need of glucocorticoid replacement therapy and withdrew the antihypertensive drugs.

Multihormonal bilateral petrosal sinus sampling (BPSS) has been proposed to improve corticotroph microadenomas prediction of lateralisation. Few series have simultaneously compared data of pituitary MRI, surgical findings and multihormonal BPSS. Seven patients (6F/1M) with Cushing's disease, mean age at diagnosis of 35 years (range 24-55) were prospectively studied to compare radiological and multihormonal BPSS data with surgical and pathological findings. In untreated patients, simultaneous measures of ACTH, TSH and prolactine (PRL) were done at time 0, 7, 15, 22 minutes after CRH (500 microgram) and TRH (200 microgram) stimulation. An intersinus gradient of 1.4 was considered as a lateralisation. All microadenomas were identified during surgery, diameters ranged from 2 to 7 mm. All patients were in long-term surgical remission. Pathological studies confirmed a tumoral tissue with ACTH immunostaining in 6/7 cases and PRL in 3/7 cases. Pituitary MRI correctly identified tumors in 4 cases, the remaining tumors were not seen. Basal and stimulated intersinus gradients of ACTH, TSH and PRL were homolateral in 6/7 cases and were coincident with surgical findings in 4/7 cases. The other three cases were contralateral to MRI and surgical data. In conclusion, simultaneous gradient of ACTH, PRL and TSH did not improve lateralisation prediction in this series. Hormonal hypersecretion was homolateral in six cases whereas pathological studies demonstrated a mixed secretion in only three cases. A preferential pituitary draining could explain these discordances. Data from our series and from others (done with CRH stimulation and ACTH-PRL measures) strongly suggest a paracrine interaction between tumoral and normal pituitary tissue.

Aims: A variety of histological variants of thymic carcinoid tumour have been described. A rare case of pigmented spindle cell carcinoid tumour of the thymus is documented and compared with the reported cases of thymic pigmented carcinoid tumour in the literature, with a discussion of the differential diagnosis of spindle cell tumours of the mediastinum., Methods and Results: A thymic tumour with ectopic adrenocorticotropic hormone (ACTH) secretion was resected from a 24-year-old man suffering from Cushing's syndrome. Histological, immunohistochemical, and ultrastructural studies revealed an ACTH-producing spindle cell carcinoid tumour harbouring pigmented melanocytes. Among four thymic pigmented carcinoid tumours reported before, only one was similar to the present case by being also an ACTH-secreting pigmented spindle cell thymic carcinoid tumour. The clinicopathological features of this tumour distinguish it from a spindle cell thymoma, spindle cell thymic carcinoma, and other mediastinal spindle cell tumours., Conclusions: This case illustrates an extremely rare variant of thymic carcinoid tumour exhibiting a spindle cell morphology and harbouring pigmented melanocytes. Awareness of this histological variant is important in the differential diagnosis of spindle cell tumours of the mediastinum.

Objectives: In about 15-20% of patients with ACTH-dependent Cushing's syndrome the source of ACTH is outside the pituitary gland. Pulmonary tumours are the most frequent, yet not unique, source of ectopic ACTH. In some instances the localisation of an ACTH-secreting tumour may be problematic. Occult ectopic ACTH secretion indicates the occurrence of ACTH-dependent hypercortisolism with an unknown origin. Another peculiarity of Cushing's syndrome may reside in the episodic cortisol hypersecretion, which can determine a pattern characterised by hypercortisolism together with periods of remission (cyclic Cushing's syndrome). We describe a very challenging case of Cushing's syndrome due to ectopic ACTH hypersecretion, showing virtually all of the most unusual features of the disease., Design: A 55-year-old woman affected by Cushing's syndrome, presenting with biochemical features of ectopic ACTH secretion, has been followed for 7 years., Methods: Thorough basal and dynamic hormonal assessment through the past 7 years is reported. In addition, the results of extensive imaging studies are presented., Results: The source of ACTH secretion has not been identified so far, and hypercortisolism has been controlled by octreotide treatment. In addition, the patient showed a cyclic pattern of hypercortisolism with a long-term remission period. A unique feature of this case is represented by the fact that we observed a temporary, yet dramatic, short-lasting remission of ACTH and cortisol hypersecretion during a pulmonary infection, which occurred while the patient was hospitalised for a periodic hormonal assessment., Conclusions: This case well represents the wide spectrum of clinical variability of Cushing's syndrome. Most interestingly, to our knowledge, this is the first report of a case of Cushing's syndrome showing a remission during an acute infection.

Pituitary carcinomas, currently defined as primary adenohypophyseal neoplasms with evidence of either brain invasion or metastatic spread, are exceptionally rare. A case of corticotroph pituitary carcinoma is reported. A 17-year-old female first presented with an invasive and clinically non-functioning pituitary macroadenoma. The primary pituitary lesion lacked atypical histological features and retrospective immunohistochemical studies confirmed its corticotrophic nature. Repeated episodes of local recurrence followed together with the acquisition of severe Cushing's disease. Local disease control was not obtained despite repeated surgical decompression and courses of radiation therapy. Systemic dissemination with multiple bone metastases became manifest eleven years after the first presentation. Atypical histological features and Crooke's hyaline change were evident in both the recurrent and metastatic disease. She remains alive at last follow-up with severe complications relating to persisting sellar and metastatic disease and ongoing endocrine dysfunction. A further 32 cases of pituitary corticotroph carcinoma reported in English are reviewed to highlight the clinicopathological features of this rare form of pituitary neoplasm. Difficulties associated with the diagnosis and management of pituitary carcinoma are also discussed.

Pituitary gland is an uncommon site of a primary cancer. Of more than 600 cases of pituitary tumors seen at the KFSH&RC between 1975 to 1998 only 3 patients had primary pituitary cancer. We have previously reported a case of pituitary fibrosarcoma arising as a rare complication of external radiotherapy (ERT) for GH-secreting pituitary adenoma (PA) [1]. We report now 2 cases of ACTH-producing primary pituitary carcinoma (ACTH-PPC); their follow-up data provide information on the natural history of this cancer. Patient #1; a 46 year old lady with Cushing's disease (CD) presented with an enlarged right cervical lymph node (LN) 2 years after having undergone a partial hypophysectomy through transsphenoidal surgery (PHYPX/TSS) and ERT for an invasive pituitary tumor. Patient #2; a 26 year old man presented with CD and underwent bilateral adrenalectomy (ADx) and pituitary ERT. Thirty-nine months later he developed Nelson's syndrome and a PHYPX/TSS was performed. Incidentally discovered hepatic metastases in this patient and an excisional biopsy of the LN in patient #1 showed histological features very similar to the pituitary tumor, and they stained strongly positive for ACTH. Perinuclear spherical hyalinized cytoplasmic inclusions were seen in the LN biopsy that corresponded to bundles of type 1 microfilaments (specific for pituitary ACTH-producing cells) seen by electron microscopy. A whole body 18-Fluoro-2-Deoxy-D-Glucose positron emission (FDG-PET) scanning, showed an intense uptake in the neck mass. A trial of octreotide did not change the exceedingly high levels of ACTH in patient #2, further supporting the diagnosis of ACTH-PPC. The clinical course of 102 months prior to his demise showed continued progression of the primary and the metastatic tumor. Patient #1, is alive at 15 months follow-up; hypercortisolemia is controlled using ketoconazole. ACTH-PPC should be entertained in a patient with CD presenting with persistent cervical lymphadenopathy. The clinical course in our patients suggests that the emergence of PC may involve a proliferative continuum from a pre-existing PA to an invasive tumor, culminating in a carcinoma. Adjunctive events such as ERT/ADx may predispose to the evolution of PC in genetically susceptible individuals. Because ERT is an effective treatment for PA its use will continue; it is important to be aware of the possible complication of primary pituitary carcinoma.

ACTH-independent Cushing's syndrome may be due to the development of ectopic hormone receptors in adrenal tissue. Thus, in food-dependent Cushing's syndrome the adrenals aberrantly express receptors for gastric inhibitory polypeptide (GIP). We present the case of a 60-year-old woman with food-dependent Cushing's syndrome whose cortisol levels increased after stimulation with CRH. In this patient with Cushing's syndrome the finding of low basal plasma cortisol levels in the late night and early morning as well as a paradoxical rise of plasma cortisol during a 7-h infusion with dexamethasone (carried out without any restriction in food intake), suggested that cortisol production was stimulated at times of food intake. Hourly measurements of plasma cortisol for 48 h revealed prominent meal-related peaks. A plasma cortisol response, elicited by oral glucose administration, could be prevented by octreotide. Plasma ACTH was low or undetectable. CRH administration was followed by a ACTH response from 3 to 16 ng/l and a plasma cortisol response from 230 to 680 nmol/l. Octreotide treatment for nearly five months induced a partial clinical and biochemical remission. Total bilateral adrenalectomy was performed. The left adrenal was grossly enlarged (7 x 5.5 x 4 cm) and the right adrenal was slightly enlarged (6 x 4 x 1.8 cm). Microscopy revealed bilateral nodular hyperplasia. Cell suspensions of adrenal tissue from the patient did respond in a dose-dependent fashion to stimulation with GIP and were very sensitive to stimulation with synthetic ACTH1-24. However, CRH had no significant effect on cortisol production in vitro. Using RT-PCR amplification and cDNA hybridization, GIP receptor was found to be overexpressed in the left and right adrenal tissues from this patient as compared to adrenal tissues from a normal individual or from non GIP-dependent adrenal Cushing's syndrome. There was no evidence of presence of adrenal CRH receptors. Thus, in this patient with food-dependent Cushing's syndrome, the CRH-induced plasma ACTH and cortisol response is probably mediated by an incomplete suppression of the HPA axis as a result of the intermittent food-dependent nature of Cushing's syndrome.

We observed the histopathological and physiological characteristics of adrenocorticotropic hormone (ACTH)-secreting adenoma cells derived from a rapidly growing pituitary adenoma, which have firm cell attachment and well-preserved hormonal function in a relatively longterm culture. Corticotrophs, obtained from a 43-year-old woman with Cushing's disease in whom plasma ACTH levels increased in response to 1-deamino-8-D-arginine vasopressin (DDAVP) stimulation and the proliferative potential was very high, were grown in tissue culture for up to 6 months. The morphological features were observed by phase contrast and electron microscopy. The cultured cells were incubated with corticotroph-releasing hormone (CRH), arginine vasopressin (AVP), or DDAVP, and ACTH in the medium was measured by radioimmunoassay (RIA). The morphology of the ACTH-secreting adenoma cells in culture revealed a mixed population of formed clusters and spindle-shaped fibroblast-like cells. The adenoma cells were immunohistochemically positive only for ACTH. On electron microscopic observation, pituitary tumor cells obtained 6 days after seeding demonstrated many secretory granules, well-developed rough endoplasmic reticulum, and mitochondria; fewer secretory granules were observed after cultivation for 24 days. ACTH levels in the incubation media were elevated with stimulation by DDAVP, AVP, or CRH. In this study, the establishment of relatively longterm culture of human pituitary adenoma cells seemed to be due to the high proliferative potential of this adenoma. This in vitro study may imply that DDAVP as well as AVP directly stimulates ACTH release from corticotropic adenoma cells.

Background: During transsphenoidal surgery (TSS) for Cushing's disease, the surgeon depends on experience to find minute adenomas. Cytological slide preparations or frozen sections, even when successful, are not specific concerning the hormone activity. In an attempt to improve accurate localization of minute ACTH adenomas, we evaluated a new intraoperative method of ACTH measurements in adenoma and anterior lobe microsamples. As most ACTH adenomas are monohormonal, the possible benefit of a GH measurement was investigated., Methods: We included pituitary tissue of 32 patients, 22 with Cushing's disease and 10 endocrine inactive pituitary adenomas as control. All patients underwent TSS by one surgeon. Preoperative data, intraoperative and perioperative hormone measurements of homogenized, weighed pituitary tissue samples, and histological findings are presented., Results: In ACTH adenomas, the median ACTH content was found to be 1,688 ng/mg, minimum 345 ng/mg. The median GH was measured at 36 ng/mg. Anterior lobe tissue contained median 80 ng ACTH/mg, maximum 279 ng/mg. Median GH was 2,200 ng/mg. In hormonally inactive adenomas ACTH was less than 0.1 ng/mg, median GH was 5.5 ng/mg. There was no overlap of ACTH content in the tissues investigated. Therefore, by adopting 300 ng ACTH/mg as a cutoff level, a clear discrimination is given. Additional GH measurements are not necessary., Conclusion: This new intraoperative method permits a clear differentiation between adenoma and pituitary tissue. In addition to intraoperative cytology and histology, this method can serve as a specific proof that the ACTH adenoma has been identified during surgery. This may be valuable in difficult cases with unclear intraoperative findings, especially after previously negative exploration.

A 29-year-old woman was admitted in March 1998 due to high plasma ACTH levels, amenorrhea and uncontrolled diabetes mellitus (DM) which had persisted since 1991. Plasma ACTH levels showed a wide range of changes: they were usually high (59-240 pg/ml), intermittently very high (336-942 pg/ml), and sometimes normal or low. Plasma cortisol levels were usually normal but were sometimes high when the ACTH levels were very high. However, even when the plasma ACTH levels were very high, she did not show any cushingoid features. DM was diagnosed as non-insulin-dependent DM. Plasma ACTH showed an excessive response to CRH, while cortisol showed a delayed response. Plasma cortisol showed a poor response to ACTH-(1-24). ACTH receptor gene analysis revealed no mutations in the ACTH receptor-coding region. MRI showed a nonenhancing mass on the left side of the pituitary. Cavernous sinus sampling showed a very high plasma ACTH level in the left cavernous sinus compared with the levels in the right cavernous sinus and peripheral blood. Sephadex G-75 gel filtration of plasma ACTH immunoreactivity in plasma obtained by cavernous sinus sampling showed mainly high molecular forms of ACTH, probably proopiomelanocortin and ACTH-beta-lipotropin. This case is a very rare form of pituitary adenoma showing intermittent secretion of high molecular ACTH unaccompanied by cushingoid features., (Copyright 2000 S. Karger AG, Basel)

A 74-year-old man developed Cushing's syndrome and hypokalemia due to ACTH-independent bilateral macronodular adrenocortical hyperplasia (AIMAH) with excessive secretion of mineralocorticoid hormones. Plasma concentrations of weak mineralocorticoids were high. The increase in plasma cortisol did not have a diurnal rhythm, and was not suppressed by a high dose of dexamethasone. Plasma ACTH was undetectable, but plasma cortisol was increased by ACTH administration. The concentrations of mineralocorticoids, especially deoxycorticosterone and corticosterone were increased, and augmented the response to ACTH administration. Plasma renin activity and aldosterone concentrations were rather suppressed. Both adrenal glands, with a total weight of 110 g, were enlarged and contained several macronodules. These nodules were composed of hyperplasia of small cortical cells and usual clear cells. This is a rare case of ACTH-independent bilateral macronodular adrenocortical hyperplasia because there were excessive secretion of mineralocorticoid and hypokalemia.

Background: Cushing's syndrome is a rare disorder. The corticotropin (ACTH)-dependent form of this syndrome generally results either from excessive ACTH secretion by a pituitary adenoma or ectopic secretion by a malignant tumor. Theoretically, the latter type can be assumed to occur more frequently in old age as the incidence of malignancy increases., Methods: Diagnostic procedures for these five cases of Cushing's syndrome consisted of 24-hour urinary cortisol excretion, plasma ACTH and serum cortisol levels, oCRH stimulatory test, low-dose and high-dose dexamethasone suppression tests, CT scan or MR imaging of the pituitary region, and bilateral inferior petrosal sinus sampling. Patients were treated with ketoconazole, if possible, and evaluated according to clinical response and 24-hour urinary cortisol excretion., Patients: The five cases presented were selected on the basis of age--75 years or older--from a total of about 100 patients presenting with Cushing's syndrome. In only three cases were signs of hypercorticism found on clinical examination. The other two patients were evaluated for adrenocortical excess because of severe hypokalemia and the fortuitous finding of enlarged adrenal glands on CT scan, respectively., Results: As a result of endocrine testing, pituitary-dependent Cushing's disease was suspected in three patients and ectopic Cushing's syndrome in two patients. Imaging techniques demonstrated only one pituitary adenoma in the first three patients and a lung tumor in one of the latter two patients. Inferior petrosal sinus sampling confirmed the suspected origin of the Cushing's syndrome in the three patients in which this procedure was performed. All three patients with pituitary-dependent Cushing's disease underwent successful clinical and biochemical treatment with ketoconazole., Conclusion: Pituitary-dependent Cushing's disease may occur more frequently in patients older than 75 years of age than has previously been assumed. Because surgical treatment is not always easily tolerated by older patients, the steroidogenesis inhibitor, ketoconazole, can be a valuable alternative for the control of hypercorticism.

Little is known about the molecular mechanisms of tumor progression in the pituitary. However, animal studies suggest that the Rb gene may be involved in the development of pituitary carcinoma. Pathologic examination of a pituitary tumor that included both benign and malignant components provided insight into this mechanism. Both benign and malignant tumors were immunoreactive for ACTH. The benign adenoma showed strong nuclear immunoreactivity for Rb, however, both the adjacent sellar carcinoma and its metastases were Rb-negative. This study suggests that loss of Rb may in some cases be important in the progression of pituitary adenoma to carcinoma.

Background: Ectopic adrenocorticotropic hormone-producing islet cell tumors of the pancreas (ACTH-ICT) are a rare cause of Cushing's syndrome with a severe and rapidly progressive clinical course., Methods: Charts were reviewed on all patients evaluated and treated for proven Cushing's syndrome caused by ACTH-ICT (n = 12), specifically for the role of surgery in the management of this disease., Results: Ten (83%) of twelve patients with ACTH-ICT had liver metastases at the time of diagnosis (eight of eight with Zollinger-Ellison syndrome, two of four without Zollinger-Ellison syndrome). Surgical management of the primary tumor included three patients who underwent distal pancreatectomy combined with hepatic resection and one patient who underwent laparoscopic enucleation of a tumor from the pancreatic tail. Eight of twelve patients underwent bilateral adrenalectomy to control symptoms of Cushing's syndrome, including three patients who underwent concurrent distal pancreatectomy and hepatic resection. Six of twelve patients died of the disease within 2 1/2 years of diagnosis, four are alive with progressive hepatic metastases, and one has biochemical evidence of disease., Conclusions: ACTH-ICT of the pancreas is an aggressive tumor, particularly when there is coproduction of gastrin. The benefit of aggressive surgical resection of primary or metastatic ACTH-ICT has not been established. However, palliative bilateral adrenalectomy is justified, because no patients had biochemical cures after aggressive surgical resection in this series.

We treated a case of ACTH-independent bilateral adrenocortical macronodular hyperplasia (AIMAH), a rare disease. The patient was a 49 year-old man having chief complaints of facial edema, muscle wasting and typical Cushing's syndrome symptoms. He was diagnosed with AIMAH by specific hormonal tests for Cushing's syndrome and CT scan. Bilateral total adrenalectomy was performed in a two-stage operation for bilateral macronodular adrenocortical hyperplasia. The resected adrenal tumor weighed 57 g on the right side and 78 g on the left, and both had a yellowish nodular surface. The histological appearance was typical AIMAH. A total of 23 AIMAH reported cases was reviewed.

Carcinoid tumour of the thymus is a rare condition, with less than a hundred cases reported in the literature. Diagnosis is complex as they are usually asymptomatic. We describe a case of a severe Cushing syndrome developed in a 51-year-old man. The diagnosis of a thymic carcinoid was established. Three years ago, the patient was treated by surgical resection of an anterior mediastinal mass. A massive tumour dissemination was detected by MIBG and CT image techniques. Both techniques are currently considered useful for this kind of diagnosis. ACTH secretion was detected immunohistochemically. Although the treatment with SMS-201-995 octreotide was effective in controlling the clinical symptoms, the patient died three months later with extensive metastases. The carcinoid tumours of the thymus associated to Cushing syndrome are aggressive tumours and usually produce local and distant metastases.

Twenty-six consecutive patients with ACTH-dependent Cushing syndrome were subjected to simultaneous, bilateral inferior petrosal sinus sampling for ACTH assay before and after ACTH-releasing hormone (CRH) stimulation. The baseline ACTH inferior petrosal sinus/periphery (IPS/P) ratio was > or = 2 in 12 of 26 patients (46%), whereas the CRH-stimulated IPS/P ratio was > or = 3 in 19 of 26 patients (73%). A pituitary adenoma, ACTH-secreting at immunostaining, was surgically proved in all of the 19 patients who had an ACTH IPS/P ratio > or = 2 basally or > or = 3 after the CRH test but also in three other patients who did not have such ratios. The value of the basal IPS/P ratio and the complete lack of ACTH increase after CRH led to the diagnosis of an ectopic ACTH syndrome in four patients: a bronchial carcinoid was found in three patients, and the site of the tumor was still unknown in the other. In conclusion, the CRH test improved the diagnostic accuracy of inferior petrosal sinus sampling from 61.5% (12 pituitary, 4 ectopic) to 92.0% (19 pituitary, 4 ectopic). Thus it should be performed during the diagnostic process.