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Cushing's syndrome, a clinical condition characterized by hypercortisolemia, exhibits distinct clinical signs and is associated with cyclic cortisol secretion in some patients. The clinical presentation of cyclic Cushing's syndrome can be ambiguous and its diagnosis is often challenging. We experienced a 72-year-old woman with cyclic ACTH-dependent Cushing's syndrome caused by a pulmonary carcinoid tumor. Diagnosis was challenging because of the extended trough periods, and the responsible lesion was initially unidentified. A subsequent follow-up computed tomography revealed a pulmonary lesion, and ectopic ACTH secretion from this lesion was confirmed by pulmonary artery sampling. Despite the short peak secretion period of ACTH (approximately one week), immunostaining of the surgically removed tumor confirmed ACTH positivity. Interestingly, stored plasma chromogranin A levels were elevated during both peak and trough periods. The experience in evaluating this patient prompted us to investigate the potential use of plasma chromogranin A as a diagnostic marker of ACTH-dependent Cushing's syndrome. A retrospective study was conducted to determine the efficacy of plasma chromogranin A in three patients with ectopic ACTH syndrome (EAS), including the present case, and six patients with Cushing's disease (CD) who visited our hospital between 2018 and 2021. Notably, plasma chromogranin A levels were higher in patients with EAS than in those with CD. Additionally, a chromogranin A level in the present case during the trough phase was lower than that in the peak phase, and was similar to those in CD patients. The measurement of plasma chromogranin A levels could aid in differentiating EAS from CD.

Introduction: Ectopic Cushing's syndrome (CS) is a rare condition nevertheless well-known to endocrinologists. The pneumologist may be called upon to treat CS not only because bronchial carcinoid tumors are the most frequent source of ectopic ACTH secretion, but also due to the fact that the immunosuppression induced by hypercorticism favors lower respiratory tract infections., Case Report: We report the case of a female patient presenting with acute respiratory failure secondary to Enterobacter cloacae pneumonia exacerbated by SC. Further investigations confirmed ectopic ACTH secretion and revealed a right upper lobe pulmonary nodule. After appropriate antibiotic therapy, the patient received preoperative adrenolytic treatment. Management by right upper lobectomy resulted in the extraction of a 12mm tumor. Pathological analysis was consistent with the diagnosis of a typical carcinoid tumor. Immunohistochemistry confirmed ACTH secretion by the tumor. Even though the postoperative course showed CS regression, the patient developed adrenal insufficiency., Conclusion: Ectopic CS induces immunosuppression, which aggravates lower respiratory tract infections. Search for a pulmonary neuroendocrine tumor should be systematic. Following control of the secretory syndrome by adrenolytic treatment, and if the diagnosis of carcinoid tumor is confirmed, surgical treatment is the preferred option., (Copyright © 2023 SPLF. Published by Elsevier Masson SAS. All rights reserved.)

Rationale: Atypical thymic carcinoid tumor is an exceedingly rare thymic neuroendocrine tumor derived from the cells of neuroendocrine system. Misdiagnosis or delayed diagnosis may result in disease progression to advanced stages and eventually leads to a poor prognosis. It is therefore necessary to make a correct diagnosis and provide an adequate treatment., Patient Concerns: A 33-year-old Chinese male presented with numbness in bilateral lower extremities and general fatigue for a month. Chest computed tomography revealed a superior anterior mediastinal mass. Thymoma was initially considered, given the location of the mass and radiographic presentation., Diagnosis: Microscopic findings showed that the tumor cells are arranged in pseudoepitheliomatous growth or irregular nested growth pattern in a background of fibroconnective tissue, with focal infiltration into adipose tissue. The chrysanthemum-like structure or beam-like structure seen often in typical carcinoid tumor was not identified in this case. The tumor cells are spindled or oval, with focal active mitosis. The immunohistochemical staining showed strong positivity for CD56, CgA and Syn, positivity for CK, ACTH, and TTF-1, negativity for Vimentin, and ki67 labeled proliferation index was up to 10% in focal areas. According to the radiological and pathological findings, the diagnosis of atypical thymic carcinoid was made., Interventions: The patient underwent surgical resection of the mass., Outcome: No recurrence or metastasis was identified during the follow up., Lessons: Because of its low incidencen, onspecific clinical symptoms, tissue location, and radiological findings, atypical thymic carcinoid tumor may sometimes be misdiagnosed as thymoma. Attention should be paid to avoid misdiagnosis., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: We aimed to evaluate and compare the clinical, biochemical and radiological profile and outcomes of patients with ectopic ACTH syndrome (EAS) and Cushing disease (CD) treated over a period of 10 years (2013-2022)., Methods: In this ambispective observational study, we collected data for 146 patients with ACTH-dependent CS (EAS, n = 23; CD, n = 94; occult ACTH source, n = 29). Relevant details were filled in a predesigned proforma and outcomes were ascertained at the most recent visit., Results: EAS was more common in males (65.2 vs. 27.6%, p < 0.001). Patients with EAS had a shorter duration of symptoms [12 (6-12) vs. 31.5 (15-48) months, p < 0.001] and were more likely to have hypokalemia (82.6 vs. 21.0%, p = 0.001), pedal edema (65.2 vs. 34.2%, p = 0.015), weight loss (34.8 vs. 4.0%, p < 0.001) and systemic infection (30.4 vs. 6.5%, p = 0.006). They also had significantly higher 8 a.m. serum cortisol, midnight serum and salivary cortisol and 8 a.m. plasma ACTH levels. Bronchial carcinoid (n = 10, 43.5%) was the most common etiology of EAS. Bilateral adrenalectomy was performed in 11 (47.8%) patients with EAS. Eight patients (34.8%) with EAS died at the last follow-up, of whom 7 (87.5%) had metastatic disease. In CD group, overall remission rate was 69.4% (56.1%, early and 13.3%, delayed) and 26.3% of patients with an initial remission had recurrence., Conclusions: Bronchial carcinoid was the most common cause of EAS in our cohort. Bilateral adrenalectomy was performed in approximately every 1 in 2 patients with EAS and approximately every 1 in 3 patients expired till the last follow-up., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Although Cushing's Syndrome (CS) is usually caused by pituitary/adrenal adenomas, in the remaining few cases, Adrenocorticotrophic hormone (ACTH) is secreted by extrapituitary neuroendocrine tumors (NET). In typical pulmonary / bronchial carcinoid tumors leading to ectopic ACTH syndrome (EAS). The main principle of treatment is the localization of the ACTH-secreting tumor and its surgical removal. In this case report, we aimed to present two typical carcinoid cases, whose ACTH and cortisol levels returned to normal after lung surgery for ectopic ACTH. One of the cases, a 32-year-old female patient with CS symptoms and signs, was referred to our department after detecting a lesion in the left lower lobe in the thorax CT, which did not show an obvious focus on cranial MRI. The other patient, a 36-year-old male, had previously undergone adrenalectomy for Cushing's syndrome and was admitted to the emergency department due to adrenal insufficiency. The lesion seen in the right lower lobe on thorax CT was evaluated as an ectopic ACTH focus. After the tumors of the patients were resected according to surgical principles, CS clinic regressed, and ACTH and cortisol values returned to normal. Pathological examinations of the surgically resected tumors were reported as typical carcinoid. With surgically removed typical carcinoids tumors, excellent longterm survival results can be achieved and hypercortisolism can be controlled.

Background: Bronchopulmonary carcinoids (BPCs) are rare malignancies but are known to be one of the most common causes of the ectopic adrenocorticotropic hormone (ACTH) syndrome. Surgery is the mainstay of therapy and one key question considering surgical treatment is the impact of local lymph node metastases. We sought to determine the risk factors and prognosis of LN metastases in resected carcinoid patients., Methods: Data of 42 patients of BPCs with lymph node metastasis who received radical surgery in Peking Union Medical College Hospital (PUMCH) from Jan 2000 to Dec 2021 were retrospectively analysed. Overall survival (OS) and progression-free survival (PFS) were analyzed using Kaplan-Meier curves. Independent prognostic factors were assessed by COX hazard proportion model., Results: It was indicated that in patients received radical surgery with local lymph node positive of BPCs, the 5-year OS and PFS rate was 74.5%, 68.3%, respectively. Multivariate Cox regression indicated that ectopic ACTH syndrome (EAS) could predict significantly to a better OS and PFS. In the subgroup analysis, the age, tumor size, Ki-67 index, histology and postoperative chemotherapy in patients with EAS had significantly differences with those without EAS., Conclusions: Our study certified R0 resection with lymphadenectomy was effective in patients with lymph nodal positive. The ectopic ACTH syndrome was a protective factor for a better prognosis, which could provide clear evidence for operations., (© 2022. The Author(s).)

Background: Ectopic Cushing syndrome (ECS) is a sporadic condition. Even uncommon is an ECS that derives from a carcinoid tumor of the thymus. These tumors may pose several diagnostic and therapeutic conundrums. This report discusses the differential diagnosis, clinicopathological findings, and effective treatment of a rare case of ECS using a minimally invasive approach., Case Presentation: A 29-year-old woman with Cushing syndrome presented with facial flushing. Physical examination revealed hypertension (blood pressure: 141/100 mmHg). A mediastinal tumor was discovered to be the cause of the patient's chronic hypokalemia and hypercortisolemia. Cortisol levels increased in the morning, reaching 47.7 ug/dL. The levels of the hormones ACTH, aldosterone, and renin were determined to be 281 pg/mL, 3.0 ng/dL, and 2.1 pg/mL, respectively. The presence of hypertension, hypokalemia, and alkalinity suggested Cushing's syndrome, which was proven to be ACTH-dependent ECS by a dexamethasone suppression test. A chest CT scan revealed inflammation in the posterior basal region of the right lower lobe. The superior anterior mediastinum was characterized by round-shaped isodensity lesions with distinct borders. She underwent thoracoscopic anterior mediastinal tumor excision via the subxiphoid technique (R0 resection); following surgery, her blood pressure returned to normal, and the hypernatremia/hypopotassemia resolved. The tumor was determined to be a thymic carcinoid. Most notably, cortisol levels fell to half of their presurgical levels after one hour of surgery, and other abnormalities corrected substantially postoperatively., Conclusion: Thoracoscopic excision of thymic tumors by subxiphoid incision may be a useful treatment option for ECS caused by neuroendocrine tumors of the thymus., (© 2022. The Author(s).)

Background : Ectopic Cushing's syndrome is a very rare condition caused by an ACTH-secreting tumor outside the pituitary or adrenal glands, and the majority of these cases are encountered in the context of paraneoplastic syndromes. The ectopic source of ACTH secretion is not always obvious to detection and can be challenging. We report a rare case, in which a hidden ACTH-secreting carcinoid tumor of the lung caused a severe refractory hypokalemia, leading us to a race against time to locate the tumor. Case presentation : A 33-year-old young male was admitted to the ICU for the management of a severe hypokalemia, and complains from several months of depression, increased weight, disabling non-radiating dorsal lower back pain and refractory arterial hypertension. The physical examination immediately suggested a Cushing's syndrome. The 24-h cortisoluria confirmed hypercortisolism and the increased ACTH level was oriented towards ACTH-dependent Cushing's syndrome. Thereafter, a dexamethasone suppression test was negative, indicating in favor of ectopic ACTH secretion. The etiological assessment via imaging and isotopes revealed a solitary pulmonary nodule at the right lower lobe estimated at 18 mm, the resection and anatomopathological analysis of which led to the diagnosis of carcinoid pulmonary tumor, and resolved hypercortisolism and its complications. Conclusion : A delayed diagnosis of Cushing's syndrome result in a consequent morbi-mortality, mainly due to cardiovascular events. The optimal treatment for ectopic Cushing's syndrome is surgical resection, thus making the localization of the tumor a key element.

Ectopic ACTH syndrome (EAS) is a potentially fatal endocrine disease that results from a variety of neuroendocrine tumors (NETs), such as small cell lung cancer (SCLC) and bronchial typical carcinoid. Typical carcinoid is usually slow growing, not associated with plasma progastrin releasing peptide (ProGRP) elevation. Here, we report a 47-year-old female smoker with progressive typical carcinoid and plasma ProGRP elevation. Several types of Cushingoid features were found on physical examination. In addition, laboratory examination showed elevated plasma ACTH and serum cortisol levels. These findings indicated ACTH-dependent Cushing's syndrome. Moreover, the serum cortisol level was not suppressed by overnight high-dose dexamethasone treatment, suggesting the presence of an extra-pituitary tumor. Contrast-enhanced brain MRI revealed no pituitary adenoma, which also supported the idea that EAS occurred in the present case. Strikingly, chest computed tomographic (CT) scan showed a single 18-mm peripheral nodule in the right middle lobe of the lung. Tumor marker analysis revealed an elevation in plasma ProGRP. These data suggested a possibility that SCLC secreted ACTH and caused EAS in this patient. Of note, the plasma ACTH level was increased (1.7 fold) in l-desamino-8-D-arginine vasopressin (DDAVP) test, also suggesting the specific clinical feature in this case. After additional imaging examinations, we performed surgical resection with the suspicion of limited SCLC. As a result, pathological examination revealed a vasopressin receptor Ib (V1b) receptor-negative bronchial typical carcinoid with ACTH production and mediastinal lymphatic metastasis. In summary, we present a case of EAS caused by progressive bronchial typical carcinoid with plasma ProGRP elevation. We propose a novel subtype of lung typical carcinoid.

Introduction: Ectopic Cushing's syndrome (ECS) is a rare condition caused by ACTH secretion by extrapituitary tumors. Its low frequency makes it difficult to acquire experience in its management. The aim of this study was to describe patients with ECS seen at the endocrinology department of a tertiary hospital over 15 years., Methods: This was a retrospective study of the clinical, biochemical and radiographic data, treatment, and course of patients with ECS seen from 2000 to 2015., Results: Nine patients (6 of them female) with a mean age of 47 years were included in the study. The clinical syndrome developed in less than 3 months in all cases but one, and most patients also had edema, hyperpigmentation and/or hypokalemia. Mean urinary free cortisol and ACTH levels were 2,840μg/24h and 204pg/mL respectively. The ectopic origin was confirmed by a combination of dynamic non-invasive tests and radiographic studies in most cases. The tumor responsible could be identified in 8 cases, and 7 patients had metastatic dissemination. Primary treatment was surgery in one patient, surgery combined with systemic therapy in 3, and chemotherapy in the other 3 patients. Bilateral adrenalectomy was required in 4 patients to control hypercortisolism. After a mean follow-up of 40 months, 3 patients died, 5 were still alive, and one had been lost to follow-up., Conclusions: Our study confirms that ECS covers a wide spectrum of tumors of different aggressiveness and nature. The ectopic origin of Cushing's syndrome can usually, be suspected and confirmed in most cases without the need for invasive tests. Control of both hypercortisolism and the tumor requires multiple treatment modalities, and multidisciplinary management is recommended., (Copyright © 2018 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.)

A thirty-eight year old patient presented with a gradual increase in weight and Cushingoid facies of two years duration. He also had orbital congestion, with puffy eyelids and corkscrew conjunctival vessels, associated with painful eye movements. An endocrine evaluation revealed raised cortisol and ACTH. Head imaging was performed which showed an enhancing tumour arising from the sphenoid sinus, with osseous erosion of the sphenoid sinus, extending to the nasopharynx, sellar and a small amount extending intracranially. He underwent an endoscopic endonasal resection of the tumour and histology revealed a low-grade carcinoid tumour with ACTH staining. The patient also underwent radiotherapy for the intracranial extension. He is currently in his fourth year of follow-up and imaging has showed a small, stable intracranial remnant. His anterior pituitary hormonal profile remains normal., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

We present an interesting case where a patient is presented with a droopy left eyelid (as part of Horner syndrome) and Cushingoid features which were a result of a Pancoast tumour (apical lung tumour in superior pulmonary sulcus) involving the left lung. This tumour was secreting ectopic adrenocorticotropic hormone (ACTH), a paraneoplastic endocrine phenomenon, which resulted in Cushing syndrome symptomatology. Though most ectopic ACTH-producing lung cancers are either small cell or carcinoid tumours, this was in fact a large cell neuroendocrine cancer (LCNEC). Patient underwent surgical resection and adjuvant/neoadjuvant chemotherapy with radiation; however, he succumbed to LCNEC given aggressive nature of the disease., (2017 BMJ Publishing Group Ltd.)

Introduction: Paraneoplastic Cushing's syndrome is a rare cause of endogenous hypercortisolism attributable to ectopic ACTH secretion by non-pituitary tumors. Imaging and biochemical results are often inconclusive and differential diagnosis with Cushing's disease can then be challenging. Moreover, these tumors may be occult and difficult to find and thus the need of new imaging tools such as (18)FDG-PET scan and (18)DOPA-PET scan., Case Report: We report a 50-year-old man who presented with very aggressive clinical features related to Cushing's syndrome. Biological work-up confirmed the hypercortisolism and was consistent with an ectopic ACTH secretion. Conventional localization techniques failed to show any tumor and bilateral adrenalectomy was performed because of life-threatening complications. Two years later, thoracic computed tomography reveals an 11 mm mass in the left lower pulmonary lobe, (18)FDG-PET scan found a non-specific mild hypermetabolism of the lung nodule, and the (18)DOPA-PET scan confirmed the high uptake of this nodule suggesting an endocrine carcinoma. Histology confirmed a typical carcinoid tumor. The tumor cells stained positive for ACTH, CD56, chromogranin and synaptophysin., Conclusion: This case illustrates the dilemma between the need for morphological diagnosis of the ectopic ACTH source and control of the life-threatening hypercortisolism. (18)FDG-PET scan and (18)DOPA-PET scan should be considered early as a secondary diagnostic tool when conventional imagery fails to show any tumor., (Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.)

A 37-year-old woman with clinical and biochemical features of ectopic adrenocorticotropic hormone (ACTH) syndrome underwent 68Ga DOTANOC PET/CT to localize the source of ectopic ACTH secretion. The images showed 35 × 45-mm retroperitoneal mass with significantly increased tracer uptake. Plasma-free metanephrines and serum chromogranin levels were normal. Whole-body 131I-MIBG scan including the retroperitoneal mass did not show any abnormal uptake. On excision, histopathology of this paravertebral abdominal mass revealed carcinoid tumor. We suggest the use of 68Ga DOTANOC PET/CT as a first-line imaging modality for localization of source of ACTH secretion in ectopic ACTH syndrome.

Ectopic ACTH syndrome is a rare but important cause of pediatric Cushing syndrome, for which management by a multidisciplinary team is required. Although diagnostic evaluation is similar to that in adults, the variation in epidemiology may sway investigations, leading to inappropriate and/or incomplete diagnostic interventions. We present a case of 15-year-old girl with symptoms of severe ACTH-dependent Cushing syndrome and two pituitary adenomas. The ectopic source of ACTH production was confirmed after petrosal venous sampling was performed. Diagnostics and perioperative management of a pulmonary carcinoid tumor producing ectopic ACTH is reviewed. In pediatric patients, as in adult patients, a pituitary lesion <6 mm on MRI is not sufficient confirmation of Cushing's disease, and appropriate diagnostic work-up should be performed to assess the source of the ACTH overproduction.

Objective: We report a 44-year old man with ectopic adrenocorticotropic hormone (ACTH) syndrome caused by bronchial carcinoid that developed Cushing syndrome., Methods: We performed several imaging studies, including chest and abdominal CT, for exploration of nodules and selective pulmonary arterial sampling for localizing a source of ectopic ACTH production., Results: The patient was diagnosed as Cushing syndrome due to ectopic production of ACTH without identification of its source(s). After 2 years' follow-up with repeated CT scans every 6-12 months and treatment with metyrapone, chest CT revealed two small nodules respectively in the segment (S) 4 and 10 of the right lung. We performed selective pulmonary arterial sampling from branches of the right pulmonary artery to obtain blood from the nodules in a reverse flow fashion: wedged sampling from the basal branch (A8, 9 and 10) revealed significant elevation of ACTH, whereas sampling from the lateral branch (A4) did not, indicating that the S10 nodule produced ACTH ectopically. The video-assisted thoracoscopic surgery removing the right inferior lobe normalized plasma ACTH, serum cortisol and 24-hour urinary free cortisol. The S10 nodule was histologically diagnosed as atypical bronchial carcinoid containing immunoreactive ACTH., Conclusions: Selective pulmonary arterial sampling was useful for localizing the lesion of ectopic ACTH production and helped make the decision for its surgical removal. This procedure should be considered once lung nodules suspicious for ectopic ACTH production are identified in patients with EAS.

Adrenocorticotropic hormone (ACTH) overproduction within the pituitary gland or ectopically leads to hypercortisolism. In this study a case of Cushing's syndrome caused by an ectopic ACTH-secreting carcinoid tumor in lung is discussed, as are the available diagnostic procedures. The patient was a 28-year-old woman with clinical features starting about 6 months previously. The results of her biochemical tests suggested ectopic Cushing's syndrome. Full-body computed tomography revealed a single nodule in the inferior lobe of the right lung. After removal of the nodule, the patient's symptoms subsided clinically, and laboratory tests confirmed remission of the hypercortisolism., (Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Ectopic ACTH secretion accounts for less that 10% of all causes of endogenous Cushing's syndrome. Carcinoids are rare thymic tumors, and when associated with ACTH hypersecretion display local or distant aggressive behavior. A 32-year-old woman was admitted to the Endocrinology Unit for obesity, moon face, facial hirsutism, hyperpigmentation, and secondary amenorrhea. Laboratory test confirmed the hypercortisolism and excess ACTH, while dexamethasone suppressive test was negative. Thorax computed tomography (CT) showed an antero-superior mediastinal tumor invading the pericardium and left mediastinal pleura. A complete resection through median sternotomy of the tumor, pericardium and left mediastinal pleura was performed. After a one-year symptom-free period, hypercortisolism recurred, confirmed by laboratory findings. Although no signs of local recurrence were seen on thorax CT, left internal mammary lymph nodes involvement and vertebral body metastases at C7 and LI were found. Refractory electrolyte disturbances could not be corrected resulting in severe cardiac arrhythmia and death from cardiac arrest. The reported case draws attention on the aggressiveness of ACTH-secralso due to the refractory electrolyte disturbances with fatal outcome.

Both severe hypokalemia and persistent hypertension are clinical symptoms of hyperaldosteronism. Hyperaldosteronism may occur as a primary or secondary syndrome. Excess ACTH produced ectopically by tumors may induce hyperaldosteronism through the mineralocorticoid activity of glucocorticoids that are upregulated by ACTH. Licorice, with the active ingredient glycyrrhiza, is also a well-known inducer of hyperaldosteronism under specific conditions. In this report, we describe a case of severe hypokalemia caused by ectopic ACTH syndrome (EAS) elicited by an intrathoracic carcinoid tumor, which had transformed to produce ACTH during the 6-year clinical course, and was modulated by licorice ingestion. Hypokalemia was not clearly recognized preoperatively but became obvious within 3 h of general anesthesia with epidural blockade. At the end of anesthesia, arterial blood gas analysis indicated severe hypokalemia ([K(+)] = 1.7 mEq/l) and metabolic alkalosis (pH 7.56, PaCO(2) = 54.9 mmHg, HCO(3)(-) = 44.5 mmol/l, BE = 21.8 mmol/l), without any typical symptoms such as muscle weakness or ECG abnormalities. The hypokalemia was resistant to potassium supplementation and persisted for 4 days. Perioperative imbalance between the administration and elimination of potassium and surgical stress might contribute to the rapid exacerbation and induce the clinical manifestation of EAS.

We present the case of a 73-year-old woman who presented with clinical features of Cushing's syndrome, confirmed biochemically with elevated levels of cortisol and adrenocorticotrophic hormone (ACTH). Petrosal venous sampling showed no ACTH gradient and MRI of pituitary was normal, suggesting ectopic ACTH production. In the course of further investigations, a thoracic CT was carried out to look for evidence of bronchial neoplasm. Although there was no discrete tumour identified, CT revealed widespread fine nodularity in the right middle and lower lobe. Subsequent trans-bronchial and video-assisted thorascopic biopsy showed pulmonary tumourlets and two typical carcinoid tumours on a background of diffuse idiopathic pulmonary neuroendocrine cell neoplasia (DIPNECH). We describe the clinical, radiological and histological features of this rare condition.

A 75-year-old woman was admitted to our hospital because of a poor glycemic control. She was found to have Cushingoid feature and dynamic endocrine tests showed elevated plasma ACTH and cortisol levels, lack of their circadian rhythm, non-suppressibility to high-dose dexamethasone, responsiveness to CRH, but not to DDAVP, and suppression to octreotide. Pituitary MRI showed an equivocal small lesion. CT scan of the chest showed two nodular lesions in the right lung (S5, S7), while a mild uptake was noted only in S5 lesion by FDG-PET, but positive uptake was only in S7 lesion by somatostatin receptor scintigraphy (SRS). Inferior petrosal sinus sampling revealed a gradient of plasma ACTH after CRH stimulation, consistent with the diagnosis of Cushing' s disease. She underwent middle and inferior lobectomy of the right lung. The resected tumor in S7 was consistent with the diagnosis of a bronchial carcinoid tumor with positive ACTH immunoreactivity, while that of S5 was cryptococcal granuloma. RT-PCR revealed abundant expressions of POMC and SSTR (-1, -2, -5), but not of CRHR and V1bR. Postoperatively, abnormal endocrine data were normalized along with improvement of hypertension and diabetes. This was a diagnostic challenging case with ectopic ACTH syndrome indistinguishable from Cushing' s disease by various endocrine and imaging tests, among which SRS successfully localized the tumor responsible for ectopic ACTH secretion.

Cushing syndrome due to adrenocorticotropic hormone secretion by a bronchial carcinoid tumor is rare. The present study reports a case of a bronchopulmonary carcinoid presenting with Cushing syndrome in a 24-year old man who was successfully treated with a right middle lobectomy. The pertinent literature is reviewed, and the pathology and clinical presentation are discussed.

Context: Establishing the cause of Cushing's syndrome (CS) can be a considerable challenge, in particular in ectopic adrenocorticotropic hormone (ACTH) syndrome, and often requires a combination of biochemical tests and imaging procedures., Subject: A 27-year-old man presented with signs of CS. P-ACTH levels were three times above the upper limit of normal (ULN) and free urinary cortisol around 2000 nmol/24 h. The work-up showed remarkable results., Results: A 2-day low-dose dexamethasone suppression test demonstrated paradoxical increases in cortisol. Sampling from the bilateral inferior petrosal sinus sampling (BIPSS) showed a central to peripheral ACTH ratio of 4.7 after corticotrophin-releasing hormone (CRH) stimulation, i.e. indicated pituitary disease, but magnetic resonance imaging of the pituitary was normal. Computed tomography (CT) scan of the lungs showed two oval-shaped masses, 1.3 x 1.8 and 1.3 x 2 cm, in the middle lobe. Both were positive at somatostatin receptor scintigraphy, compatible with tumors or inflammatory lesions. Subsequently, (11)C-5-hydroxytryptophan-PET showed distinct uptake in the tumors but not elsewhere. Two carcinoids situated 3 cm apart, both staining for ACTH, were removed at surgery., Conclusion: This unique case with dual bronchial carcinoids inducing hypercortisolism illustrates the problems with identifying the source of ACTH in CS. Possibly, an abnormal regulation of ACTH production in response to dexamethasone, or steroid-induced tumor necrosis, explains the paradoxical outcome at dexamethasone suppression, and the false positive result at BIPSS reflects an unusual sensitivity of the pituitary corticotrophs to CRH in this patient. The work-up illustrates the great value of (11)C-5-hydroxytryptophan-PET as a diagnostic procedure when other investigations have produced ambiguous results.

Objective: We describe a case of Cushing's syndrome due to ectopic ACTH secretion, where the only potential source on conventional imaging was a tiny benign-appearing lung nodule, which failed to take up radiolabelled octreotide., Design and Methods: To determine whether the patient might respond to therapeutic administration of octreotide, a test dose was given., Results: Compared to ACTH and cortisol levels on a control day, the levels following the test dose of octreotide were lower. Subsequent therapeutic administration of subcutaneous octreotide normalised urine free cortisol, with symptomatic improvement, pending evaluation for surgery. Eventual resection of the lung nodule resulted in cure of hypercortisolism. Histological examination of the resected specimen confirmed bronchial carcinoid staining positive for ACTH., Conclusions: This is one of the few cases described where ectopic ACTH secretion secondary to bronchial carcinoid responded to somatostatin analogue therapy. The case was also unusual in that the tumour responded despite not taking up radiolabelled octreotide.

A case of a 71-year-old male with ectopic adrenocorticotropic polypeptide (ACTH)-producing thymic carcinoid tumor presenting Cushing's syndrome was reported. This patient had symptoms of fatigue and a polyposia for 2 years before a mediastinal tumor was detected. Chest computed tomography (CT) scan demonstrated an anterior mediastinal mass, and serum ACTH and cortisol level revealed very high. Secretion of cortisol was not inhibited in an 8-mg dexamethazone suppression test. We diagnosed ectopic ACTH-producing tumor, and performed complete excision of the thymus including thymic tumor. Histologically, the tumor demonstrated typical carcinoid with the positivity of ACTH immunostaining. After the operation, ACTH and cortisol levels were reduced and the clinical symptoms were improved rapidly. We have concluded that it is important to control serum perioperative cortisol level for the prevension of morbidity.

Among endocrine disorders, Cushing's syndrome (CS) is certainly one of the most challenging to endocrinologists due to the difficulties that often appear during investigation. The diagnosis of CS involves two steps: confirmation of hypercortisolism and determination of its etiology. Biochemical confirmation of the hypercortisolaemic state must be established before any attempt at differential diagnosis. Failure to do so will result in misdiagnosis, inappropriate treatment, and poor management. It should also be kept in mind that hypercortisolism may occur in some patients with depression, alcoholism, anorexia nervosa, generalized resistance to glucocorticoids, and in late pregnancy. Moreover, exogenous or iatrogenic hypercortisolism should always be excluded. The three most useful tests to confirm hypercortisolism are the measurement of 24-h urinary free cortisol levels, low-dose dexamethasone-suppression tests, and determination of midnight serum cortisol or late-night salivary cortisol. However, none of these tests is perfect, each one has different sensitivities and specificities, and several are usually needed to provide a better diagnostic accuracy. The greatest challenge in the investigation of CS involves the differentiation between Cushing's disease and ectopic ACTH syndrome. This task requires the measurement of plasma ACTH levels, non-invasive dynamic tests (high-dose dexamethasone suppression test and stimulation tests with CRH or desmopressin), and imaging studies. None of these tests had 100% specificity and their use in combination is usually necessary. Bilateral inferior petrosal sinus sampling is mainly indicated when non-invasive tests do not allow a diagnostic definition. In the present paper, the most important pitfalls in the investigation of CS are reviewed.

Ectopic adrenocorticotropic secretion (EAS) is responsible for 12-17% of cases of Cushing's syndrome (CS) and covers a range of tumours, from undetectable benign lesions to widespread metastases. The syndrome is often associated with severe hypercortisolaemia, which aggravates the underlying condition. EAS requires a complete workup that includes the establishment of endogenous CS, diagnosis of adrenocorticotropic hormone (ACTH) dependency, localization of the source of ACTH secretion and rapid biochemical control of hypercortisolaemia. Dynamic endocrine tests should include inferior petrosal sinus sampling with CRH stimulation. Localization studies depend on the availability of reliable high-resolution cross-sectional imaging. This systematic review of the largest published series of patients with EAS (over 380 patients) reveals the common trends in the prevalence and management of this syndrome. The concept of 'occult' EAS has been revisited and the terms 'overt' and 'covert' EAS introduced. In addition to small cell lung carcinoma, the most common causes of ectopic EAS are bronchial carcinoids, thymic tumours, islet cell tumour of the pancreas, medullary thyroid carcinomas, and phaeochromocytomas. Their prevalence and the best localization modalities are presented. Medical and surgical management is discussed on the basis of the extensive experience of major referral centres.

We report a case of a 45 year-old man who presented initially with a non-functioning pituitary macroadenoma. A routine chest radiography done preoperatively revealed a right lung nodule which was confirmed by computed tomography (CT) of the thorax. Transfrontal hypophysectomy was performed while a conservative approach was taken for the lung nodule. Four years later, he presented acutely with adrenocorticotrophic hormone (ACTH) dependent Cushing's syndrome which resolved following a right lobectomy. Histological examination revealed an atypical carcinoid. To our knowledge, this is the first reported case of an ectopic ACTH secreting pulmonary carcinoid found in association with a non-functioning pituitary macroadenoma.

GH secretagogues (GHS) have been used for the differential diagnosis of ACTH-dependent Cushing's syndrome (CS) since 1997 due to their ability to increase ACTH and cortisol levels in Cushing's disease. The aim of this study was to correlate ACTH response to GH-releasing peptide-6 (GHRP-6) in vivo with GH secretagogue receptor type 1a (GHSR-1a) mRNA expression in a patient with lung carcinoid tumor. The patient was a 26-yr-old male with diagnosis of ACTH-dependent CS. He presented negative responses to human CRH and desmopressin tests; yet, a significant increase in ACTH after the GHRP-6 test was observed. Sellar magnetic resonance imaging (MRI) showed slight posterior hypointensity, but bilateral petrosal sinus sampling did not show central gradient. Computed tomography (CT) and MRI of thorax/abdomen/cervical were negative and 111In-pentetreotide scintigraphy depicted abnormal uptake on the right lung. The patient was submitted to right thoracotomy for exeresis of lung nodule and hilar lymph node which were characterized as atypical lung carcinoid tumor and he presented clinical and laboratorial remission after surgery. GHSR-1a mRNA expression was studied with real-time quantitative PCR and tumor data were compared with fragments of normal lung and pituitary. There was a higher GHSR-1a expression in the lung carcinoid tumor as compared with normal tissues. The ACTH response to GHRP-6 in a patient with ectopic ACTH production by a lung carcinoid tumor was associated with GHSR-1a expression in the tumor tissue, suggesting an association between GHSR-1a mRNA overexpression and the in vivo response to GHS.

Hepatic carcinoid tumors are very uncommon; most are clinically non-functional and very few present with the symptoms of carcinoid syndrome. ACTH-producing carcinoid tumors most commonly originate in the lung or thymus and present insidiously with bronchospasm and/or chest mass. Occasionally, ectopic ACTH syndromes have been reported in association with pancreatic islet cell tumors, medullary thyroid cancer, pheochromocytoma, small-cell lung carcinoma, and rarely, ovarian and prostate tumors. We report here a patient with an ectopic ACTH-secreting primary hepatic carcinoid tumor who presented with cushingoid appearance, profound proximal muscle weakness, severe lower extremity edema, and markedly elevated urinary free cortisol. ACTH levels were in the low normal range. A solitary vascular hepatic lesion was found on magnetic resonance imaging, which was isodense with the surrounding liver on octreotide scan and photopenic on an 18-fluorodeoxyglucose (18FDG)-positron emission tomography (PET) scan. Following surgical resection of the hepatic tumor, histopathology confirmed an ACTH-secreting neuroendocrine tumor (NET), the patient had complete resolution of hypercortisolemic symptoms and remains in remission, now 4 yr after hepatic tumor resection. This case reports the first ACTH-secreting primary hepatic NET presenting as ectopic Cushing's syndrome. Interesting aspects of this case include the presence of a pituitary incidentaloma, the low normal ACTH, and photopenia on 18FDG-PET imaging.

In 1990, a 55-yr-old woman was admitted to the Medical Department of our hospital for severe hypercortisolism complicated by secondary diabetes mellitus and serious hypokalemia. Although inferior petrosal sinus sampling did not show any significant difference between central and peripheral ACTH concentration, suggesting an ectopic source of ACTH secretion, diagnostic imaging was negative and Cushing's disease due to hyperplasia of the pituitary intermediate lobe was suspected. Medical treatment with bromocriptine and cyproheptadine led to a rapid and stabile normalization of adrenal function, so that after two months cyproheptadine was stopped and bromocriptine was tapered to a smaller dose. An attempt to discontinue medical treatment, carried out 3 yr later, was followed by a quick increase of ACTH and cortisol levels, which were normalized by the resumption of the bromocriptine. Adrenal function remained normal until 1994 when hypercortisolism relapsed despite the treatment. Chest radiography and computed tomography (CT) scan detected a 6 mm nodule in the middle lobe of the lung which proved to be a neuroendocrine tumor, with immunohistochemical positivity for ACTH. Nests of neuroendocrine cells (tumorlets) were also demonstrated in the surrounding lung tissue. After the lobectomy, the patient recovered completely from Cushing's syndrome and no symptoms and/or signs of recurrence have been observed over the subsequent follow-up period. Although cyclical spontaneous Cushing's syndrome could not be excluded, there was strong evidence that medical treatment with bromocriptine might have played a key role in long-lasting remission. To our knowledge, this is the second case described in literature of Cushing's syndrome caused by neuroendocrine lung tumor responsive to bromocriptine.

The ectopic ACTH syndrome (EAS) caused by thymic carcinoid is rare and its diagnosis remains a challenge to the endocrinologist. Here are six cases of EAS with a typical Cushing habitus accompanied by hyperpigmentation and hypokalemia. For all six patients, the high dose (8 mg) dexamethasone suppression test (HDDST) showed lack of suppression, computed tomography (CT) scanning documented anterior mediastinal masses, and the mediastenal tumors removed were confirmed as ACTH secreting thymic carcinoids by positive ACTH and NSE staining. Our data indicate that HDDST chest radiologic imaging and other laboratory examinations will greatly assist in diagnosing the thymic carcinoid-induced EAS at an earlier stage, which will significantly improve the long-term survival of the patient.

A 43-year-old man presented with fluctuating symptoms of weight gain, shortness of breath, pretibial oedema, associated with anxiety and memory disturbances. Laboratory investigation revealed an adrenocorticotropin (ACTH)-dependent cyclical Cushing's syndrome characterised by remarkable variations in urinary cortisol excretions ranging from 27 to 28,050 nmol/ 24 h. Magnetic resonance imaging (MRI ) of the pituitary was normal and ectopic ACTH production was suspected. A tumour in the right anterior mediastinum was revealed on octreotide receptor scintigraphy, which had initially been overlooked on computed tomography (CT) scanning. A thymic carcinoid tumour was suspected, which was supported by increased levels of urinary serotonin, while platelet serotonin and urinary 5-hydroxyindoleacetic acid levels were normal. The tumour was removed surgically and histological examination revealed an atypical thymic carcinoid tumour. Postoperatively, the patient's symptoms disappeared rapidly. He underwent external radiotherapy and is still free of symptoms after almost two years of follow-up. For clinical practice, a cyclical Cushing's syndrome should be suspected in any patient with clinical signs of Cushing's syndrome but normal biochemistry. Repeated measurement of urinary cortisol excretion is then required to establish or rule out the diagnosis.

Thymic carcinoid in multiple endocrine neoplasia type 1 (MEN 1) is previously reported as a non-ACTH producing tumor. The present case is a 39-year-old man with mortal outcome from thymic carcinoid and Cushing's syndrome with high plasma ACTH. The symptom was first observed at age 29 and was relieved after extended thymectomy, with reduction of ACTH level. The tumor was positive for ACTH, Grimelius silver staining and Chromogranin A. The finding of primary hyperparathyroidism, pituitary adenoma, and a novel germline nonsense mutation (W423X) established the diagnosis of MEN 1. Cushing's syndrome due to ACTH producing thymic carcinoid should be also considered as one phenotype of the MEN 1 spectrum.

Discrepancy of plasma ACTH levels measured by different immunoradiometric assays (IRMA) in a case with malignant gastric carcinoid causing ectopic ACTH syndrome was examined by gel chromatography and immunohistochemical analysis. A 49-year-old male was found to have a large gastric tumor, with muscle wasting, hypertension, diabetes and hypokalemia caused by hypercortisolemia. His plasma ACTH levels, although initially elevated, were found to be almost in normal ranges. The discrepancy of plasma ACTH levels was proven to be due to different IRMA kits used; the initial assay was performed by a kit that could recognize high-molecular weight (HMW) form as well as ACTH(1-39), but the later assay by another kit that could recognize only ACTH(1-39). Pathological examination of the gastric tumor was consistent with the diagnosis of malignant carcinoid. Immunohistochemical study revealed that immunoreactivity of proopiomelanocortin (POMC) was positive within the tumor cells, whereas those of ACTH and prohormone convertase 1/3 were negative. Molecular sieving analysis of patient's plasma by gel chromatography coupled with ACTH radioimmunoassay which could recognize HMW form and ACTH(1-39) and two different IRMAs revealed that the predominant form of ACTH was HMW form with a minor peak of ACTH(1-39). This is a rare case of ectopic ACTH syndrome caused by malignant gastric carcinoid with preferential production of HMW form of ACTH, possibly due to unprocessed POMC.

Cushing syndrome caused by adrenocorticotropic hormone (ACTH) production from solid tumors can result in life-threatening hypercortisolemia. Ectopic ACTH production is most commonly associated with bronchial carcinoids and squamous cell carcinoma of the lung. We report a case of Cushing syndrome caused by ectopic ACTH production from a carcinoid of the duodenum. The patient presented to an outside hospital in hypertensive crisis and diabetic ketoacidosis. After stabilization, diagnostic studies including a serum cortisol level, and computed tomography (CT) scans of the head, chest, abdomen, and pelvis revealed hypercortisolemia and a large mass in the head of the pancreas. Pancreaticoduodenectomy was performed. Pathologic investigation revealed a 1-cm carcinoid of the duodenum with two large metastatic lymph nodes near the head of the pancreas. This is the first reported case in the English literature of Cushing syndrome caused by ectopic ACTH production from a carcinoid of the duodenum.

Intraoperative [111In]-pentetreotide scintigraphy with a hand-held gamma detector probe has recently been proposed to increase the intraoperative detection rate of small neuroendocrine tumors and their metastases. We report a case of a 28-yr-old woman with ectopic Cushing's syndrome due to an ACTH-secreting bronchial carcinoid, in whom the use of radioguided surgery improved disease management. At presentation, radiolabeled pentetreotide scintigraphy was the only procedure able to detect the ectopic source of ACTH. After radiologic confirmation, the patient underwent removal of a bronchial carcinoid, with disease persistence. After surgery, pentetreotide scintigraphy showed pathologic uptake in the mediastinum not previously detected at surgery and only subsequently confirmed by radiologic studies. Despite a second thoracic exploration, hormonal, scintigraphic, and radiological evidence of residual disease persisted. Radioguided surgery was then performed using a hand-held gamma probe 48 h after iv administration of a tracer dose of radiolabeled [111In-DTPA-D-Phe1]-pentetreotide, which permitted detection and removal of multiple residual mediastinal lymph node metastases. Clinical and radiologic cure, with no evidence of tracer uptake at pentetreotide scintigraphy, was subsequently observed. The use of an intraoperative gamma counter appears a promising procedure in the management of metastatic ACTH-secreting bronchial carcinoids.

A 21-year-old woman with Cushing's syndrome presented with a mediastinal tumor. Ectopic ACTH syndrome was diagnosed and the tumor was resected. The histopathological diagnosis was thymic atypical carcinoid. Despite all tumor lesions having been resected, the tumor relapsed and multiple metastatic lesions grew aggressively. Combination chemotherapy with cisplatin and etoposide (VP16) was administered to control tumor progression, and achieved marked therapeutic effects. Maintenance chemotherapy with carboplatin and VP16 achieved long-term tumor control. This case indicates that some patients with atypical carcinoid tumor are good responders to chemotherapy with platinum agents and VP16.

A 34-year-old man was diagnosed with clinical Cushing's syndrome based on circadian fluctuation of plasma adrenocorticotropin and serum cortisol levels and Liddle's-method. The presence of ectopic adrenocorticotropin production was suspected. Urine 5-hydroxyindoleaceturic acid level was high. Chest computed-tomography scan revealed a mass in the right upper lung. 111In-pentetrotide scintigraphy demonstrated marked accumulation in the right upper lung. We suspected an adrenocorticotropin-producing bronchial carcinoid. Plasma adrenocorticotropin and serum cortisol levels decreased immediately following resection of the tumor. Adrenocorticotropin production by tumor cells was confirmed by immunohistochemistry. This case indicates 111In-pentetrotide scintigraphy could be successfully used to identify and localize ectopic adrenocorticotropin-producing bronchial carcinoid.