Discriminatory value of the low-dose dexamethasone suppression test in establishing the diagnosis and differential diagnosis of Cushing's syndrome

Consensus guideline for the diagnosis and management of pituitary adenomas in childhood and adolescence: Part 2, specific diseases

Pituitary adenomas are rare in children and young people under the age of 19 (hereafter referred to as CYP) but they pose some different diagnostic and management challenges in this age group than in adults. These rare neoplasms can disrupt maturational, visual, intellectual and developmental processes and, in CYP, they tend to have more occult presentation, aggressive behaviour and are more likely to have a genetic basis than in adults. Through standardized AGREE II methodology, literature review and Delphi consensus, a multidisciplinary expert group developed 74 pragmatic management recommendations aimed at optimizing care for CYP in the first-ever comprehensive consensus guideline to cover the care of CYP with pituitary adenoma. Part 2 of this consensus guideline details 57 recommendations for paediatric patients with prolactinomas, Cushing disease, growth hormone excess causing gigantism and acromegaly, clinically non-functioning adenomas, and the rare TSHomas. Compared with adult patients with pituitary adenomas, we highlight that, in the CYP group, there is a greater proportion of functioning tumours, including macroprolactinomas, greater likelihood of underlying genetic disease, more corticotrophinomas in boys aged under 10 years than in girls and difficulty of peri-pubertal diagnosis of growth hormone excess. Collaboration with pituitary specialists caring for adult patients, as part of commissioned and centralized multidisciplinary teams, is key for optimizing management, transition and lifelong care and facilitates the collection of health-related quality of survival outcomes of novel medical, surgical and radiotherapeutic treatments, which are currently largely missing.

Ovine CRH Stimulation and 8 mg Dexamethasone Suppression Tests in 323 Patients With ACTH-Dependent Cushing's Syndrome

CONTEXT

Determining the etiology of adrenocorticotropin (ACTH)-dependent Cushing's syndrome (CS) is often difficult. The gold standard test, inferior petrosal sinus sampling (IPSS), is expensive and not widely available.

OBJECTIVE

Evaluate the performance of the corticotropin-releasing hormone stimulation test (CRH-ST) and the 8 mg high-dose dexamethasone suppression test (HDDST) in distinguishing Cushing's disease (CD) from ectopic ACTH syndrome (EAS).

METHODS

Retrospective review in a tertiary referral center. A total of 323 patients with CD or EAS (n = 78) confirmed by pathology or biochemical cure (n = 15) in 96% underwent CRH-ST and HDDST performed between 1986 and 2019. We calculated test sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value, and diagnostic accuracy (DA) for the diagnosis of CD, and determined optimal response criteria for each test, alone and in combination.

RESULTS

The CRH-ST performed better than the HDDST (DA 91%, 95% CI 87-94% vs 75%, 95% CI 69-79%). Optimal response criteria were a ≥40% increase of ACTH and/or cortisol during the CRH test and a ≥69% suppression of cortisol during the HDDST. A ≥40% cortisol increase during the CRH test was the most specific measure, PPV 99%. Seventy-four percent of subjects had concordant positive CRH test and HDDST results, yielding Se 93%, Sp 98%, DA 95%, and PPV 99%, with a pretest likelihood of 85%. A proposed algorithm diagnosed 64% of patients with CD with near perfect accuracy (99%), obviating the need for IPSS.

CONCLUSION

CRH is a valuable tool to correctly diagnose the etiology of ACTH-dependent CS. Its current worldwide unavailability impedes optimal management of these patients.

Paediatric and adolescent ectopic Cushing's syndrome: systematic review

OBJECTIVE

The data on clinical, biochemical, radiological characteristics, and outcomes in paediatric ectopic adrenocorticotropic hormone syndrome (EAS) are limited owing to rarity of the condition. We report three new cases and perform a systematic review of paediatric EAS.

DESIGN AND METHOD

Case records of paediatric and adolescent EAS patient's ≤20 years presenting at our centre between 1997 and 2021 were retrospectively reviewed, and a systematic review of the literature published between January 1970 and December 2022 was performed.

RESULTS

A total of 161 patients including 3 new patients from our centre were identified. Bronchial neuroendocrine tumours (NET) (28.5%), thymic NET (22.9%), primitive cell-derived tumours (18.6%), and gastro-entero-pancreatic-NET (13.7%) were the common causes. Primitive cell-derived tumours were the most common in the first decade (24/45, 53.4%) and were the largest (82 [60-100] mm), whereas bronchial NETs predominated during the second decade (42/116, 36.2%) and were the smallest (15 [10-25] mm). Computed tomography localized 92.9% (118/127) of paediatric EAS patients. Immediate postoperative remission was attained in 77.9% (88/113) patients, whereas 30.4% (24/79) relapsed over a median (IQR) period of 13 (8-36) months. Over a median (IQR) follow-up of 2 (0.6-4.6) years, 31.4% of patients died. The median survival was higher in bronchial NET than in other tumour groups. Distant metastasis and tumour size were independent negative predictors of survival.

CONCLUSIONS

Aetiological profile of paediatric and adolescent EAS is distinct from that of adults. Bronchial NETs have the best long-term survival, whereas distant metastasis and tumour size predict poor survival.

Enhancing Cushing's disease diagnosis: exploring the impact of desmopressin on ACTH gradient during BIPSS

Introduction

The differential diagnosis between Cushing's disease (CD) and ectopic ACTH syndrome (EAS) is complex, and bilateral inferior petrosal sinus sampling (BIPSS) is considered the gold-standard test. However, BIPSS with corticotropin-releasing hormone (CRH) stimulation is rarely available.

Objective

This retrospective cohort study aimed to assess the accuracy of the inferior petrosal sinus to peripheral ACTH gradient (IPS:P) before and after desmopressin stimulation for the differential diagnosis of ACTH-dependent Cushing's syndrome (CS), applying different cutoff values.

Methods

A total of 50 patients (48 with CD and 2 with EAS) who underwent BIPSS were included in this study. The sensitivity and specificity of IPS:P in BIPSS before and after desmopressin stimulation were evaluated. Various cutoff values for IPS:P were examined to determine their diagnostic accuracy.

Results

Using the traditional IPS:P cutoff, the sensitivity was 85.1% before stimulation, 89.6% after stimulation, and a combined sensitivity of 91.7%. Applying cutoff values of IPS:P >1.4 before and >2.8 after stimulation, the sensitivity was 87.2% and 89.6%, respectively, with a combined sensitivity of 91.7%. Receiver operating characteristic (ROC) curve analysis determined optimal cutoff values of 1.2 before stimulation and 1.57 after stimulation, resulting in a sensitivity of 93.6% and 93.8%, respectively, with a combined sensitivity of 97.9%. Specificity remained at 100% throughout all analyses. Among the 43 patients who responded positively to stimulation, 42 (97.7%) did so within the first three minutes, and all 43 (100%) did so within the first five minutes. None of the assessed clinical variables predicted the ACTH response to stimulation in BIPSS with statistical significance.

Discussion

ACTH stimulation with desmopressin during BIPSS improves the accuracy of IPS:P, making it a valuable tool for investigating ACTH-dependent Cushing's syndrome. Considering the low risk of complications, we recommend the use of desmopressin stimulation during BIPSS for the differential diagnosis of ACTH-dependent CS.

Continuing Challenges in the Definitive Diagnosis of Cushing's Disease: A Structured Review Focusing on Molecular Imaging and a Proposal for Diagnostic Work-Up

The definitive diagnosis of Cushing's disease (CD) in the presence of pituitary microadenoma remains a continuous challenge. Novel available pituitary imaging techniques are emerging. This study aimed to provide a structured analysis of the diagnostic accuracy as well as the clinical use of molecular imaging in patients with ACTH-dependent Cushing's syndrome (CS). We also discuss the role of multidisciplinary counseling in decision making. Additionally, we propose a complementary diagnostic algorithm for both de novo and recurrent or persistent CD. A structured literature search was conducted and two illustrative CD cases discussed at our Pituitary Center are presented. A total of 14 CD (n = 201) and 30 ectopic CS (n = 301) articles were included. MRI was negative or inconclusive in a quarter of CD patients. ¹¹C-Met showed higher pituitary adenoma detection than ¹⁸F-FDG PET-CT (87% versus 49%). Up to 100% detection rates were found for ¹⁸F-FET, ⁶⁸Ga-DOTA-TATE, and ⁶⁸Ga-DOTA-CRH, but were based on single studies. The use of molecular imaging modalities in the detection of pituitary microadenoma in ACTH-dependent CS is of added and complementary value, serving as one of the available tools in the diagnostic work-up. In selected CD cases, it seems justified to even refrain from IPSS.

Pediatric Ectopic Cushing Syndrome Caused by Hepatic Neoplasms: A Case Report and Systematic Review

Ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is rare in children, and localizing the source of EAS is often challenging. Here, we report EAS in an adolescent boy who presented with Cushingoid features and had endogenous ACTH-dependent hypercortisolism on hormonal evaluation. Abdominal ultrasound and CT revealed a hepatic lesion with characteristics suggestive of hemangioma, whereas the lesion was tracer non-avid on ⁶⁸Ga-DOTANOC positron emission tomography/CT. A regional sampling of ACTH was done to confirm the hepatic lesion as the source of EAS, and a definitive ACTH gradient was observed between the hepatic vein and the right internal jugular vein. Further, a preoperative biopsy of the lesion revealed a small round cell tumor with positive immunostaining for ACTH and synaptophysin, suggestive of a neuroendocrine tumor. The patient was managed with partial hepatectomy, resulting in hormonal and clinical remission of Cushing syndrome. In a systematic review of pediatric EAS due to primary hepatic tumors (n = 11), calcifying nested stromal epithelial cell tumors were the most common. EAS-associated hepatic tumors were larger (≥10 cm) except benign primary hepatic neuroendocrine tumors (PHNET). The latter were misdiagnosed as hemangioma in two cases by anatomical imaging but correctly diagnosed by somatostatin receptor scintigraphy. Hepatic tumors causing EAS in children required extensive resection, except benign PHNET. Nevertheless, all benign tumors with an uncomplicated perioperative course demonstrated disease-free survival over a median follow-up period of two years.

Dynamic testing for differential diagnosis of ACTH-dependent Cushing Syndrome: a systematic review and meta-analysis

OBJECTIVE

Diagnostic accuracy of testing currently used for the differential diagnosis of Cushing's disease (CD) vs ectopic -ACTH secretion (EAS) is difficult to interpret. The present study aimed to identify and evaluate the diagnostic accuracy of corticotropin-releasing hormone (CRH) test, desmopressin test, and high-dose dexamethasone suppression test (HDDST) when used to establish a CD or EAS diagnosis.

DESIGN

This study is a systematic review of the literature and meta-analysis.

METHODS

MEDLINE, OVID, and Web of Science databases were searched for articles published between the years 1990-2021. Articles included described at least one test(s) (CRH, desmopressin, or HDDST) and the diagnostic reference standard(s) (histopathology, petrosal sinus sampling, surgical remission, imaging, and long-term follow-up) used to establish a CD or EAS diagnosis.

RESULTS

Sixty-two studies were included: 43 reported the use of HDDST, 32 CRH test, and 21 desmopressin test. CRH test was found to have the highest sensitivity in detecting CD (ACTH 86.9%, 95% confidence interval [CI] 82.1-90.6, cortisol 86.2%, 95%CI 78.3-91.5) and the highest specificity in detecting EAS (ACTH 93.9%, 95%CI 87-98.3, cortisol 89.4%, 95%CI 82.8-93.7). This resulted in a high diagnostic odds ratio (58, 95%CI 43.25-77.47), large area under the curve, and a receiver-operating characteristic (ROC) of 0.934. The diagnostic accuracy of HDDST and desmopressin test(s) was lower than that of the CRH test.

CONCLUSION

The meta-analysis indicates that a patient with a positive ACTH response after a CRH test is highly likely to have CD. Further studies analysing role of dynamic testing in addition to imaging are needed.

Biochemical testing to differentiate Cushing's disease from ectopic ACTH syndrome

The differential diagnosis of ACTH-dependent Cushing's syndrome is often a diagnostic challenge that has been debated in numerous studies. In this short article, we will discuss the performance and main drawbacks of the biochemical tests used for this diagnosis.

A noninvasive scoring model for the differential diagnosis of ACTH-dependent Cushing's syndrome: a retrospective analysis of 311 patients based on easy-to-use parameters

OBJECTIVES

The differential diagnosis of ACTH-dependent Cushing's disease (CS) is challenging. The gold standard approach bilateral inferior petrosal sinus sampling (BIPSS) is expensive and invasive, while other noninvasive tests, like the high-dose dexamethasone suppression test (HDDST), provide unsatisfactory diagnostic accuracy. This study aimed to find a new noninvasive practical approach with higher diagnostic accuracy to differently diagnose ACTH-dependent CS, which can be used in centers where BIPSS cannot be applied.

METHODS

264 Cushing's disease (CD) patients and 47 ectopic ACTH secretion syndrome (EAS) patients were analyzed in this single-center retrospective study (2011-2021). The multivariate logistic model was used to construct the scoring model.

RESULTS

Female (adjusted OR 3.030, 95%CI 1.229-7.471), hypokalemia (0.209, 0.076-0.576), ACTH (0.988, 0.982-0.994), MRI pituitary lesion positive (8.671, 3.521-21.352), and HDDST positive (2.768, 1.139-6.726) have a strong association with the differential diagnosis of ACTH-dependent CS and were included in the final multivariable logistic regression model. A -14-to-14-point noninvasive scoring model was built on the model. The AUC of the noninvasive scoring model was 0.915 (95% CI 0.869-0.960), significantly higher than the AUC of HDDST (0.756, 95% CI 0.685-0.825, P = 0.004). The optimal cutoff of the model was ≥0 to diagnose CD. The sensitivity of the noninvasive scoring model was 91.3% (95% CI 87.3%-94.1%), and the specificity was 80.9% (95% CI 67.5%-89.6%). When the model's sensitivity was 100.0%, the cutoff was ≥ -10 with a specificity of 19.2%; when the model's specificity was 100.0%, the cutoff was ≥ 13 with a sensitivity of 22.7%.

CONCLUSIONS

We developed a noninvasive scoring model to distinguish CD and EAS in ACTH-dependent CS patients with higher diagnostic utility than HDDST in the same cohort. The noninvasive scoring model might be applied in areas where BIPSS is unavailable, the CRH is hard to obtain, or the desmopressin stimulation is not widely applied. It also provided a triage tool for selecting patients that might benefit the most from a further BIPSS test.

Molecular Derangements and the Diagnosis of ACTH-Dependent Cushing's Syndrome

Endogenous Cushing's syndrome (CS) is associated with morbidities (diabetes, hypertension, clotting disorders) and shortens life because of infections, pulmonary thromboembolism, and cardiovascular disease. Its clinical presentation is immensely variable, and diagnosis and treatment are often delayed. Thus, there are many opportunities for basic and clinical research leading to better tests, faster diagnosis, and optimized medical treatments. This review focuses on CS caused by excessive adrenocorticotropin (ACTH) production. It describes current concepts of the regulation of ACTH synthesis and secretion by normal corticotropes and mechanisms by which dysregulation occurs in corticotrope (termed "Cushing's disease") and noncorticotrope (so-called ectopic) ACTH-producing tumors. ACTH causes adrenal gland synthesis and pulsatile release of cortisol; the excess ACTH in these forms of CS leads to the hypercortisolism of endogenous CS. Again, the differences between healthy individuals and those with CS are highlighted. The clinical presentations and their use in the interpretation of CS screening tests are described. The tests used for screening and differential diagnosis of CS are presented, along with their relationship to cortisol dynamics, pathophysiology, and negative glucocorticoid feedback regulation in the two forms of ACTH-dependent CS. Finally, several gaps in current understanding are highlighted in the hope of stimulating additional research into this challenging disorder.

Distinguishing Cushing's disease from the ectopic ACTH syndrome: Needles in a haystack or hiding in plain sight?

In the context of ACTH-dependent Cushing's syndrome, ectopic ACTH secretion from a neuroendocrine tumour is not uncommon, and needs to be carefully differentiated from pituitary-dependent Cushing's syndrome, Cushing's disease, in order to optimise therapy. Some cases may be quite obvious, while in others the diagnosis may be difficult to confirm and the source of ACTH problematic, as many clinical and biochemical tests may overlap with Cushing's disease. Imaging is essential, but needs to be interpreted in the light of both anatomical as well as functional imaging modalities. In this review we summarise some of the main diagnostic problems, and emphasise the multimodal and interdisciplinary nature of the diagnostic pathways.

Consensus statement by the French Society of Endocrinology (SFE) and French Society of Pediatric Endocrinology & Diabetology (SFEDP) on diagnosis of Cushing's syndrome

Cushing's syndrome is defined by prolonged exposure to glucocorticoids, leading to excess morbidity and mortality. Diagnosis of this rare pathology is difficult due to the low specificity of the clinical signs, the variable severity of the clinical presentation, and the difficulties of interpretation associated with the diagnostic methods. The present consensus paper by 38 experts of the French Society of Endocrinology and the French Society of Pediatric Endocrinology and Diabetology aimed firstly to detail the circumstances suggesting diagnosis and the biologic diagnosis tools and their interpretation for positive diagnosis and for etiologic diagnosis according to ACTH-independent and -dependent mechanisms. Secondly, situations making diagnosis complex (pregnancy, intense hypercortisolism, fluctuating Cushing's syndrome, pediatric forms and genetically determined forms) were detailed. Lastly, methods of surveillance and diagnosis of recurrence were dealt with in the final section.

The promising role of risk scoring system for Cushing syndrome: Time to reconsider current screening recommendations

Despite the current screening approach for Cushing syndrome (CS), delayed diagnosis is common due to broad spectrum of presentation, poor discriminant symptoms featured in diabetes and obesity, and low clinical index of suspicion. Even if initial tests are recommended to screen CS, divergent results are not infrequent. As global prevalence of type 2 diabetes and obesity increases, CS may not be frequent enough to back routine screening to avoid false-positive results. This represents a greater challenge in countries with limited health resources. The development of indexes incorporates clinical features and biochemical data that are largely used to provide a tool to predict the presence of disease. In clinical endocrinology, indexes have been used in Graves' ophthalmology, hirsutism, and hypothyroidism. The use of clinical risk scoring system may assist clinicians in discriminating CS in the context of at-risk populations and, thus, may provide a potential intervention to decrease time to diagnosis. Development and validation of clinical model to estimate pre-test probability of CS in different geographic source population may help to establish regional prediction model for CS. Here, we review on the latest progress in clinical risk scoring system for CS and attempt to raise awareness for the use, validation, and/or development of clinical risk scores in CS.

Outcome of CRH stimulation test and overnight 8 mg dexamethasone suppression test in 469 patients with ACTH-dependent Cushing's syndrome

OBJECTIVE

To evaluate diagnostic accuracy of the corticotropin-releasing hormone (CRH) stimulation test and the overnight 8 mg dexamethasone suppression test (DST) for the differentiation of Cushing's disease (CD) and ectopic Cushing's syndrome (ECS).

METHODS

Retrospective study in 6 European centers. Inclusion criteria: patients with a) overt adrenocorticotropin (ACTH)-dependent Cushing's syndrome at the time of dynamic testing, b) histopathological confirmed tumors and/or c) postoperative biochemical remission and/or adrenal insufficiency. Optimal cut-offs were calculated via receiver operating characteristic (ROC) analysis using CD as reference.

RESULTS

469 patients were analyzed [78% females; median age 43 years (IQR 19)]. CRH test and overnight 8 mg DST were performed in 420 [CD, n=394 (94%); ECS, n=26 (6%)] and 237 patients [228 CD (96%), 9 ECS (4%)]. Both tests were performed in 205 patients (44%). The post-CRH %-increase at 30 minutes of both ACTH (cut-off ≥31%, sensitivity 83%, specificity 85%, AUC 0.81) and cortisol (cut-off ≥12%, sensitivity 82%, specificity 89%, AUC 0.86) discriminated best between CD and ECS. A test duration of >60 minutes did not improve diagnostic performance of the CRH test. The optimal cortisol cut-off for the %-suppression during the 8 mg DST was ≥55% (sensitivity 80%, specificity 78%, AUC 0.75).

CONCLUSION

The CRH test has equivalent sensitivity but higher specificity than the 8 mg DST and is therefore the test of first choice. The diagnostic outcome of ACTH and cortisol is well comparable, however, sampling beyond 60 minutes post-CRH does not provide diagnostic benefits.

A MEN1 Patient Presenting With Multiple Parathyroid Adenomas and Transient Hypercortisolism: A Case Report and Literature Review

BACKGROUND

Multiple endocrine neoplasia type 1 (MEN1) is a hereditary endocrine syndrome caused by mutations in MEN1 tumor suppressor gene.

CASE PRESENTATION

A 53-year-old Chinese female was admitted to Division of Endocrinology, Tongji Hospital, for hypercalcemic crisis. Increased level of parathyroid hormone (PTH) was confirmed by laboratory tests, and imaging examination showed multiple parathyroid adenomas. Based on gene analysis, the patient was diagnosed as MEN1 associated hyperparathyroidism (HPT) by gene analysis with c.1378C>T (p.Arg460Ter) mutation in MEN1 gene. Her condition was complicated by transient hypercortisolism, mammary mass and uterine leiomyoma. After subtotal parathyroidectomy, PTH and serum calcium levels returned to normal.

CONCLUSION

HPT with multiple parathyroid adenomas is an indication of MEN1 gene mutation. Serum cortisol and its circadian rhythm can be abnormal in the presence of hypercalcemia and high PTH. These parameters can return to normal after parathyroidectomy.

Consensus on diagnosis and management of Cushing's disease: a guideline update

Cushing's disease requires accurate diagnosis, careful treatment selection, and long-term management to optimise patient outcomes. The Pituitary Society convened a consensus workshop comprising more than 50 academic researchers and clinical experts to discuss the application of recent evidence to clinical practice. In advance of the virtual meeting, data from 2015 to present about screening and diagnosis; surgery, medical, and radiation therapy; and disease-related and treatment-related complications of Cushing's disease summarised in recorded lectures were reviewed by all participants. During the meeting, concise summaries of the recorded lectures were presented, followed by small group breakout discussions. Consensus opinions from each group were collated into a draft document, which was reviewed and approved by all participants. Recommendations regarding use of laboratory tests, imaging, and treatment options are presented, along with algorithms for diagnosis of Cushing's syndrome and management of Cushing's disease. Topics considered most important to address in future research are also identified.

Cushing's disease

Cushing's disease (CD) is the most prevalent cause of endogenous hypercortisolism. CD is responsible for multiple co-morbidities and increased mortality. Accurate and prompt diagnosis and optimal treatment are essential to improve the prognosis of CD. However, the diagnosis of CD is probably one of the most difficult in endocrinology and, therefore, diagnostic workup should be performed in an experienced center. Transsphenoidal surgery performed by an expert surgeon is the only therapeutic option that can offer definitive cure and remains the first-line treatment in most patients. Second-line treatments include pharmacotherapy, pituitary radiotherapy and bilateral adrenalectomy. The second-line therapeutic strategy is complex, must be individualized and performed in a multidisciplinary expert center. Symptomatic treatments of persisting co-morbidities after remission, which are responsible for increased mortality and impaired quality of life is an important part of medical management.

Rapidly progressive ACTH-dependent Cushing’s disease masquerading as ectopic ACTH-producing Cushing’s syndrome: illustrative case

BACKGROUND

Cushing’s disease (CD) remains a challenging condition to diagnose and treat. This case study highlights the challenges of diagnosing CD when faced with discrepant clinical, biochemical, and radiological findings.

OBSERVATIONS

A 62-year-old man presented with rapid evolution of symptoms, including depression, fatigue, and extreme muscle atrophy, which resulted in the patient being a wheelchair user over the course of a few months. His rapid clinical course in conjunction with hypercortisolemia in the setting of a pituitary macroadenoma involving the cavernous sinus, two large pulmonary nodules, and urine-free cortisol levels in the thousands suggested an aggressive ectopic adrenocorticotropic hormone (ACTH) source. After extensive testing ruled out CD from an ectopic source and because of the patient’s abrupt clinical deterioration, the authors concluded that the source was likely an aggressive pituitary adenoma. Therefore, the authors performed an endonasal transsphenoidal approach for resection of the pituitary adenoma involving the cavernous sinus, and the patient was scheduled for radiosurgery to control tumor progression.

LESSONS

Although extremely high levels of cortisol and ACTH are associated with ectopic Cushing’s syndrome, they may also indicate an aggressive form of CD. Suspicion should be maintained for hypercortisolemia from a pituitary source even when faced with discrepant information that may suggest an ectopic source.

A rare case of ectopic ACTH syndrome with rhabdomyolysis

BACKGROUND

Manifestations of hypokalaemia in ectopic adrenocorticotropic hormonesyndrome(EAS) vary from mild muscle weakness to life-threatening arrhythmia. Herein, we present a rare case of EAS with concomitant rhabdomyolysis(RM) as a result of intractable hypokalaemia.

CASE PRESENTATION

A 64-year-old man was admitted for limb weakness and facial hyperpigmentation for 2 weeks. Lab tests revealed intractable hypokalaemia (lowest at 1.8 mmol/L) and metabolic alkalosis. The diagnosis of RM was based on a creatine kinase(CK)level of 5 times the upper limit. The elevated CK and myohemoglobin (Mb) levels returned to within the normal range after the alleviation of hypokalaemia. The patient was diagnosed with ACTH-dependent Cushing's syndrome (CS) based on unsuppressed serum cortisol after a low-dose dexamethasone suppression test(LDDST) and remarkably elevated ACTH levels. The diagnosis of EAS was made based on the results of a high-dose dexamethasone suppression test(HDDST) and bilateral inferior petrosal sinus sampling(BIPSS). Multiple lymph nodes in the left supraclavicular fossa, right root of neck, mediastinum and bilateral hili of the lung were found with abnormal uptake of ⁶⁸Ga-DOTA-NOC. Mediastinoscopic lymph node biopsy was performed. The pathological diagnosis was small-cell and large-cell neuroendocrine carcinoma with positive ACTH staining. The patient was prescribed mifepristone and received one cycle of chemotherapy. The patient could not tolerate subsequent chemotherapy and died of dyscrasia.

CONCLUSIONS

RM is a rare complication of EAS with insidious onset and atypical clinical manifestations. Serum potassium levels should be vigilantly monitored to avoid RM in EAS.

An Optimized Pathway for the Differential Diagnosis of ACTH-Dependent Cushing's Syndrome Based on Low-Dose Dexamethasone Suppression Test

CONTEXT

Traditionally, low-dose dexamethasone suppression test (LDDST) was used to confirm the diagnosis of Cushing's syndrome (CS), and high-dose dexamethasone suppression test (HDDST) was used to differentiate Cushing's disease (CD) and ectopic adrenocorticotropin (ACTH) syndrome (EAS), but some studies suggested that HDDST might be replaced by LDDST. For the differential diagnosis of CS, dexamethasone suppression test was usually combined with other tests such as bilateral petrosal sinus sampling (BIPSS) and pituitary magnetic resonance imaging, but the optimal pathway to incorporate these tests is still controversial.

OBJECTIVES

To develop an optimized pathway for the differential diagnosis of CD and EAS based on LDDST.

DESIGN AND SETTING

Single-center retrospective study (2011-2019).

PATIENTS

Two hundred sixty-nine CD and 29 EAS patients with pathological diagnosis who underwent consecutive low- and high-dose DST.

RESULTS

For the differential diagnosis of CD and EAS, the area under curve (AUC) of LDDST using urine free cortisol (0.881) was higher than that using serum cortisol (0.685) (p < 0.001) in head-to-head comparison among a subgroup of 108 CD and 10 EAS. The AUC of LDDST (0.883) was higher than that of HDDST (0.834) among all the included patients. With the cutoff of <26%, the sensitivity and specificity of LDDST were 39.4% and 100%. We designed a new pathway in which BIPSS was only reserved for those patients with unsuppressed LDDST and adenoma <6mm, yielding an overall sensitivity of 97.7% and specificity of 86.7%.

CONCLUSION

LDDST had similar value to HDDST in differentiating CD and EAS using the specific cutoff point. The pathway that combined LDDST and BIPSS could differentiate CD and EAS accurately.

Non-invasive Diagnostic Strategy in ACTH-dependent Cushing's Syndrome

CONTEXT

Inferior petrosal sinus sampling (IPSS) is used to diagnose Cushing's disease (CD) when dexamethasone-suppression and CRH tests, and pituitary magnetic resonance imaging (MRI), are negative or give discordant results. However, IPSS is an invasive procedure and its availability is limited.

OBJECTIVE

To test a noninvasive diagnostic strategy associated with 100% positive predictive value (PPV) for CD.

DESIGN

Retrospective study.

SETTING

Two university hospitals.

PATIENTS

A total of 167 patients with CD and 27 patients with ectopic ACTH-syndrome investigated between 2001 and 2016.

MAIN OUTCOME MEASURE(S)

Performance of a strategy involving the CRH and desmopressin tests with pituitary MRI followed by thin-slice whole-body computed tomography (CT) scan in patients with inconclusive results.

RESULTS

Using thresholds of a cortisol increase > 17% with an ACTH increase > 37% during the CRH test and a cortisol increase > 18% with an ACTH increase > 33% during the desmopressin test, the combination of both tests gave 73% sensitivity and 98% PPV of CD. The sensitivity and PPV for pituitary MRI were 71% and 99%, respectively. CT scan identified 67% EAS at presentation with no false-positives. The PPV for CD was 100% in patients with positive responses to both tests, with negative pituitary MRI and CT scan. The Negative Predictive Value was 100% in patients with negative responses to both tests, with negative pituitary MRI and positive CT scan. Using this strategy, IPPS could have been avoided in 47% of patients in whom it is currently recommended.

CONCLUSIONS

In conjunction with expert radiologic interpretation, the non-invasive algorithm studied significantly reduces the need for IPSS in the investigation of ACTH-dependent Cushing's syndrome.

Cushing's syndrome: Overview of clinical presentation, diagnostic tools and complications

Cushing's syndrome (CS) is a severe condition that results from chronic exposure to elevated circulating cortisol levels; it is a rare but potentially life-threating condition, especially when not timely diagnosed and treated. Even though the diagnosis can be straightforward in florid cases due to their typical phenotype, milder forms can be missed. Despite the availability of different screening tests, the diagnosis remains challenging as none of the available tools proved to be fully accurate. Due to the ubiquitous effect of cortisol, it is easy understandable that its excess leads to a variety of systemic complications including hypertension, metabolic syndrome, bone damages and neurocognitive impairment. This article discusses clinical presentation of CS with an eye on the most frequent cortisol-related comorbidities and discuss the main pitfalls of first- and second-line tests in endogenous hypercortisolism diagnostic workup.

Hypothalamic-pituitary-adrenal axis feedback sensitivity in different states of back pain

Pain normally signals a threat to bodily integrity and causes emotional distress. Acute pain serves a protective function, yet, when pain turns chronic, the protective function is lost. A chain of psychophysiological alterations including changes in the stress regulation system, apparent in dysfunctional activity and responsivity of the hypothalamic-pituitary-adrenal (HPA) axis, might be an important factor in this context. Moreover, maladaptive responses may be complicated by affective comorbid symptoms such as anxiety and depression, and alter nociceptive processing. However, the relationship among pain chronicity, stress regulation, and contributing components of comorbid symptomatology as well as somatosensory profiles has rarely been examined. In the present study, we obtained diurnal cortisol profiles at baseline and feedback regulation (following a dexamethasone suppression test (DST)) in subacute (SABP) and chronic (CBP) back pain patients and healthy control individuals (HC). We also assessed anxiety, depression and chronic stress levels and used quantitative sensory testing (QST) to detect sensory abnormalities. We found a hyper-suppression of cortisol following DST and thus enhanced negative stress feedback sensitivity in SABP compared to both CBP and HC. In SABP, DST-related cortisol levels were negatively associated with pain intensity, mediated by cold pain thresholds and anxiety. These data support a stress model of pain chronicity and suggest that stress responses might be indicators of individual vulnerability in the transition period of subacute pain.

Two types of ectopic Cushing syndrome or a continuum? Review

BACKGROUND

Two types of ectopic Cushing syndrome (ECS) are described: ECS associated with aggressive neoplasms, and ECS with indolent and occult tumors, however, there is a lack of studies that thoroughly review their characteristics.

METHODS

A systematic review was carried out on PUBMED of all the papers about the ECS, in order to better define the types of this subcategory of Cushing's syndrome, highlighting the differential aspects between these subgroups.

RESULTS

It was found that in 50% of cases the prototypic "aggressive" ECS is caused by small cell lung carcinomas (SCLC). In these cases, the clinical presentation may be atypical, predominating the signs and symptoms derived from the protein catabolism. Cortisol and ACTH levels are extremely high, the clinical presentation is abrupt (< 3-6 months) and the tumor is usually advanced, being impossible a curative treatment. On the other hand, "indolent" ECS is mainly represented by carcinoid tumors (CT). In these cases the clinical presentation overlaps enormously with that of Cushing's disease (CD). Cortisol and ACTH levels are slightly elevated, the clinical presentation is progressive (> 6 months) and the prognosis is usually good, and a curative treatment is possible in about 75% of the cases.

CONCLUSION

Although there is no absolute differentiation between the two extremes of ECS, a classification could be established in two groups, guided by its clinical and biochemical characteristics, and mainly by the type and stage of the ACTH-secreting tumor. However, a small percentage of tumors do not fit in this simple grouping, and may present both phenotypes or an intermediate one.

The Ectopic Adrenocorticotropic Hormone Syndrome: Rarely Easy, Always Challenging

Despite modern imaging techniques, differentiating ectopic adrenocorticotropic hormone (ACTH) syndrome from pituitary-dependent Cushing's syndrome, Cushing's disease, is especially difficult when well-differentiated carcinoids are the source of ACTH secretion, particularly pulmonary carcinoid tumors. ACTH-secreting pulmonary carcinoids, like the corticotroph adenomas causing Cushing's disease, are often small and difficult to detect, and patients present with a gradual onset of the classical signs and symptoms of Cushing's syndrome, indistinguishable from the presentation of Cushing's disease. Hence, the differential diagnosis relies on a combination of clinical assessment, dynamic biochemical tests, inferior petrosal sinus sampling, and multimodal imaging, each with its own caveats and pitfalls.

UTILITY OF A SINGLE LATE-NIGHT PLASMA CORTISOL AND ACTH FOR THE DIAGNOSIS OF CUSHING SYNDROME

OBJECTIVE

To evaluate the diagnostic efficacy of various screening tests for the diagnosis of Cushing syndrome (CS).

METHODS

Thirty-five patients with CS and 16 patients of pseudo-CS were enrolled. Assessment of 24-h urinary free cortisol (UFC), late-night salivary cortisol (LNSC), overnight dexamethasone suppression test (ONDST), late-night plasma cortisol (LNPC), and adrenocorticotropic hormone (ACTH) on outpatient basis, and during sleep as well as in awake state after 48 hours of hospital admission.

RESULTS

We found that 24-h UFC performed the best among the screening tests with sensitivity, specificity and areas under the curve (AUCs) of 96.0%, 99%, and 0.988, respectively, at a cut-off of 144.6 μg/24 h. A cut-off of 10.5 nmol/L for LNSC had sensitivity 85.7%, specificity 88.2%, and an AUC of 0.897. A cut-off of 412.4 nmol/L for LNPC on outpatient basis had sensitivity 88.2%, specificity 91.2%, and an AUC of 0.957. Cut-offs of 215 and 243.3 nmol/L for LNPC during sleep and awake states after acclimatization had sensitivity, specificity, and an AUC of 94.1%, 88.2%, and 0.958, respectively. An ONDST cut-off of 94.6 nmol/L provided sensitivity, specificity, and an AUC of 96.0%, 99.03% and 0.995, respectively. A cut-off of 30.3 pg/mL for late-night ACTH on outpatient basis had sensitivity 67.6%, specificity 99.9%, and an AUC 0.796.A cut-off of 22.6 pg/mL for ACTH during sleep state after acclimatization had sensitivity, specificity, and an AUC of 73.5%, 99.2%, and 0.827, respectively.

CONCLUSION

UFC is the best screening test for CS. Furthermore, single measurements of LNPC and ACTH help to establish the diagnosis and ACTH dependency of CS in the majority of patients with CS.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone AUC = area under the curve CRH = corticotropin-releasing hormone CS = Cushing syndrome ECLIA = electrochemiluminescence immuno-assay LDDST = low-dose dexamethasone suppression test LNPC = late-night plasma cortisol LNSC = late-night salivary cortisol ONDST = overnight dexamethasone suppression test RIA = radio-immuno assay UFC = urinary free cortisol.

Cushing Syndrome: Diagnostic Workup and Imaging Features, With Clinical and Pathologic Correlation

OBJECTIVE

Cushing syndrome (CS) is a constellation of clinical signs and symptoms resulting from chronic exposure to excess cortisol, either exogenous or endogenous. Exogenous CS is most commonly caused by administration of glucocorticoids. Endogenous CS is subdivided into two types: adrenocorticotropic hormone (ACTH) dependent and ACTH independent.

CONCLUSION

Cushing disease, which is caused by a pituitary adenoma, is the most common cause of ACTH-dependent CS for which pituitary MRI can be diagnostic, with bilateral inferior petrosal sinus sampling useful in equivocal cases. In ectopic ACTH production, which is usually caused by a tumor in the thorax (e.g., small cell lung carcinoma, bronchial and thymic carcinoids, or medullary thyroid carcinoma) or abdomen (e.g., gastroenteropancreatic neuroendocrine tumors or pheochromocytoma), CT, MRI, and nuclear medicine tests are used for localizing the source of ACTH. In ACTH-independent CS, which is caused by various adrenal abnormalities, adrenal protocol CT or MRI is usually diagnostic.

Second-line tests in the differential diagnosis of ACTH-dependent Cushing's syndrome

INTRODUCTION

Diagnosing Cushing's syndrome (CS) can be a challenge, especially in ACTH-dependent CS, when it comes to detecting the origin of ACTH secretion.

MATERIALS AND METHODS

Retrospective data were collected on 170 patients with ACTH-dependent CS (149 CD, 21 EAS) referring to two endocrinology units, focusing on three non-invasive tests: dexamethasone 8 mg overnight challenge (HDDST); corticotrophin-releasing hormone (CRH) assay and the desmopressin (DDAVP) test.

RESULTS

Patients with EAS were slightly older and had higher ACTH, serum and urinary cortisol levels than patients with CD (p < 0.01). CD patients had a stronger ACTH and cortisol response after CRH injection (p < 0.0001), and a more pronounced reduction in cortisol levels after HDDST (p < 0.0001). A threshold percentage ACTH increase after CRH stimulation of 72.4 % was able to identify CD with a sensitivity (SE) of 76 % (95 % CI 68-83) and a specificity (SP) of 100 % (95 % CI 83-100). As for HDDST, a cortisol suppression >52.7 % below the basal level suggested a pituitary origin with a SE of 88 % (95 % CI 81-93) and a SP of 90 % (95 % CI 68-99). There were no cases of EAS with positive responses to both these tests. Increases in ACTH and cortisol levels after the DDAVP test were also higher in CD than in EAS (p < 0.01), though the SE and SP were lower.

CONCLUSIONS

Patients with CD showed a stronger response to HDDST and CRH, and the adopted cut-offs showed a good SE and SP in discriminating them from patients with EAS. Concordant tests indicated CD when positive, whereas no response to either test was highly suggestive of EAS. The DDAVP test was of limited utility in the diagnostic phase. In conclusion, the choice of tests may play an important part in the differential diagnosis of ACTH-dependent CS.

POSTSURGICAL RECURRENT CUSHING DISEASE: CLINICAL BENEFIT OF EARLY INTERVENTION IN PATIENTS WITH NORMAL URINARY FREE CORTISOL

OBJECTIVE

To assess the performance of biochemical markers in the detection of recurrent Cushing disease (CD), as well as the potential benefit of early intervention in recurrent CD patients with elevated late-night salivary cortisol (LNSC) and normal urinary free cortisol (UFC).

METHODS

The design was a single-center, retrospective chart review. Patients treated by the authors from 2008-2013 were included. Recurrence was defined by postsurgical remission of CD with subsequent abnormal LNSC, UFC, or dexamethasone suppression test (DST).

RESULTS

We identified 15 patients with postsurgical recurrent CD after initial remission; all but one underwent testing with LNSC, DST, and UFC. Although 12 of 15 patients had normal UFC at time of recurrence, DST was abnormal in 11 of 15, and all 14 patients with LNSC results had ≥1 elevated measurement. Nine patients (7 with normal UFC) showed radiologic evidence of a pituitary tumor at time of recurrence. Among the 14 patients with available follow-up data, 12 have demonstrated significant improvement since receiving treatment. Five patients underwent repeat pituitary surgery and 4 achieved clinical and biochemical remission. Eight patients received mifepristone or cabergoline, and 6 showed clinical and/or biochemical improvement. Three patients (2 with prior mifepristone) underwent bilateral adrenalectomy and 2 demonstrated significant clinical improvements.

CONCLUSION

LNSC is more sensitive than UFC or DST for detection of CD recurrence. Prompt intervention when LNSC is elevated, despite normal UFC, may yield significant clinical benefit for many patients with CD. Early treatment for patients with recurrent CD should be prospectively evaluated, utilizing LNSC elevation as an early biochemical marker.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone CD = Cushing disease CS = Cushing syndrome CV = coefficient of variation DST = dexamethasone suppression test IPSS = inferior petrosal sinus sampling LNSC = late-night salivary cortisol QoL = quality of life TSS = transsphenoidal adenoma resection UFC = urinary free cortisol.

Ectopic adrenocorticotropic hormone syndrome caused by neuroendocrine tumors of the thymus: 30-year experience with 16 patients at a single institute in the People's Republic of China

Background and purpose

Thymic neuroendocrine carcinomas (TNECs) are extremely uncommon. Certain cases of TNECs can produce the adrenocorticotropic hormone (ACTH) and cause ectopic ACTH syndrome (EAS). The current literature on this topic consists mainly of case reports, and therapeutic guidelines are lacking. The aim of this study was to discuss the diagnosis, surgical management, and prognosis of EAS caused by TNECs to improve clinical experience with this rare disease.

Methods

From June 1984 to June 2014, at the Peking Union Medical College Hospital, the surgical interventions and follow-up outcomes of 16 consecutive patients (eight men and eight women) with EAS caused by TNECs were retrospectively analyzed.

Results

The median age was 32.5 years (range: 13–47 years), and the median disease duration was 8.5 months (range: 1–150 months). All patients presented with clinical and biochemical evidence indicating a diagnosis of Cushing’s syndrome. Contrast-enhanced thoracic computed tomography scans were critical to locating the ACTH-producing tumor and evaluating the feasibility of resection. All patients underwent surgery. One patient died of septicemia in the intensive care unit 2 weeks after surgery. No other morbidity or mortality occurred during the perioperative period. The median overall survival (OS) was 41 months (95% CI: 30.3–51.7 months), and the progression-free survival was 28 months (95% CI: 21.6–34.3 months). Both overall survival (P=0.002) and progression-free survival (P=0.030) improved significantly after complete resection.

Conclusion

TNEC is an extremely aggressive disease that should be considered when treating patients with Cushing’s syndrome due to ectopic ACTH secretion. In particular, all suspected patients should undergo contrast-enhanced thoracic computed tomography scans to facilitate early diagnosis. The current first-line treatment is surgical resection, and complete resection is a favorable prognostic factor. However, additional patients and a longer follow-up will be needed to determine the variables that are predictive of survival and to improve patient prognosis.

Bilateral symmetrical adrenal hypermetabolism on FDG PET/CT due to Cushing syndrome in well differentiated neuroendocrine carcinoma

The (18)F-FDG PET/CT scan has been suggested for whole-body imaging to identify ectopic adrenocorticotrophic hormone secreting tumours, but there are some challenges involved. The case of a patient is presented, who was admitted with the pre-diagnosis of ectopic ACTH syndrome. On the CT, a nodular lesion was detected in the medial segment of the right lung. The FDG uptake of the lesion seemed to be increased visually, but was not pathological quantitatively (SUVmax: 1.8) on the PET/CT. There was also diffuse increased uptake (SUVmax: 14.2) in the enlarged adrenal glands. The lesion was reported as a possible malignant lesion with low FDG affinity, such as a low grade neuroendocrine tumour, while the diffuse enlarged adrenal glands with high uptake were interpreted as diffusely hyperplasic, due to Cushing's syndrome. The patient was treated with a surgical wedge resection. The histopathological diagnosis confirmed that the tumour was a grade 1 well-differentiated neuroendocrine carcinoma.

Conventional and Nuclear Medicine Imaging in Ectopic Cushing's Syndrome: A Systematic Review

CONTEXT

Ectopic Cushing's Syndrome (ECS) can be a diagnostic challenge with the hormonal source difficult to find. This study analyzes the accuracy of imaging studies in ECS localization.

EVIDENCE ACQUISITION

Systematic review of medical literature for ECS case series providing individual patient data on at least one conventional imaging technique (computed tomography [CT]/magnetic resonance imaging) and one of the following: 111In-pentetreotide (OCT), 131I/123I-metaiodobenzylguanidine, 18Ffluoro-2-deoxyglucose-positron emission tomography (FDG-PET), 18F-fluorodopa-PET (F-DOPA-PET), 68Ga- DOTATATE-PET/CT or 68Ga-DOTATOC-PET/CT scan (68Gallium-SSTR-PET/CT).

EVIDENCE SUMMARY

The analysis comprised 231 patients (females, 50.2%; age, 42.617 y). Overall, 52.4%(121/231) had "overt" ECS,18.6% had "occult" ECS, and 29% had "covert" ECS. Tumors were located in the lung (55.3%), mediastinum-thymus (7.9%), pancreas (8.5%), adrenal glands (6.4%), gastrointestinal tract (5.4%), thyroid (3.7%), and other sites (12.8%), and primary tumors were mostly bronchial neuroendocrine tumors (NETs) (54.8%), pancreatic NETs (8%), mediastinum-thymus NETs (6.9%), gastrointestinal NETs (5.3%), pheochromocytoma (6.4%), neuroblastoma (3.2%), and medullary thyroid carcinoma (3.2%). Tumors were localized byCTin66.2%(137/207), magnetic resonance imaging in 51.5% (53/103), OCT in 48.9% (84/172), FDG-PET in 51.7% (46/89), F-DOPAPET in 57.1% (12/21), 131/123I-metaiodobenzylguanidine in 30.8% (4/13), and 68Gallium-SSTRPET/CT in 81.8% (18/22) of cases. Molecular imaging discovered 79.1% (53/67) of tumors unidentified by conventional radiology, with OCT the most commonly used, revealing the tumor in 64%, followed by FDG-PET in 59.4%. F-DOPA-PET was used in only seven covert cases (sensitivity, 85.7%). Notably, 68Gallium-SSTR-PET/CT had 100% sensitivity among covert cases.

CONCLUSIONS

Nuclear medicine improves the sensitivity of conventional radiology when tumor site identification is problematic. OCT offers a good availability/reliability ratio, and FDG-PET was proven useful. 68Gallium-SSTR-PET/CT use was infrequent, despite offering the highest sensitivity.

ACTH after 15 min distinguishes between Cushing's disease and ectopic Cushing's syndrome: a proposal for a short and simple CRH test

OBJECTIVE

The aim of the present study was to validate criteria of corticotropin-releasing hormone (CRH) stimulation and 8 mg dexamethasone suppression (high-dose dexamethasone suppression, HDDS) to distinguish the etiology of ACTH-dependent Cushing's syndrome.

SUBJECTS AND METHODS

We retrospectively analyzed cortisol and ACTH after the injection of 100 μg human CRH in confirmed Cushing's disease (CD, n=78) and confirmed ectopic Cushing's syndrome (ECS, n=18). Cortisol and ACTH increase (in percentage above basal (%B)) at each time point, maximal increase (Δmax %B), and area under the curve (AUC %B) were analyzed using receiver operator characteristics (ROC) curve analyses. Cortisol suppression (%B) after 8 mg of dexamethasone was evaluated as a supplementary criterion.

RESULTS

An increase in ACTH of ≥ 43%B at 15 min after CRH was the strongest predictor of CD, with a positive likelihood ratio of 14.0, a sensitivity of 83%, a specificity of 94%, a positive predictive value of 98% and a negative predictive value of 58%. All of the other criteria of stimulated ACTH and cortisol levels were not superior in predicting CD in response to CRH injection. The addition of cortisol suppression by dexamethasone did not increase the discriminatory power. However, the combination of a positive ACTH response at 15 min and a positive HDDS test excluded ECS in all cases.

CONCLUSION

The present findings support the use of plasma ACTH levels 15 min after the injection of human CRH as a response criterion for distinguishing between CD and ECS. The addition of the HDDS test is helpful for excluding ECS when both tests are positive.

[Primary Neuroendocrine Carcinoma of Thymus Caused Cushing Syndrome: Surgical Treatment and Prognosis Analysis]

背景与目的

胸腺原发神经内分泌癌为一种罕见疾病，部分肿瘤可以分泌促肾上腺皮质激素导致库欣综合征，手术切除肿瘤是治疗的关键。本研究回顾性总结并探讨胸腺原发神经内分泌癌所致库欣综合征临床诊断及手术治疗方法，并行预后分析，提高对此罕见病种的认识及诊疗水平。

方法

回顾性分析北京协和医院1987年11月-2013年6月间收治的14例由胸腺原发神经内分泌癌导致的库欣综合征患者的临床资料。

结果

14例患者，男性8例，女性6例，中位年龄29岁，中位病程4.0个月(1个月-44个月)，术前多项内分泌检查及影像学检查诊断并定位胸腺病变，经手术切除后血皮质醇及血促肾上腺皮质激素均下降(P < 0.01)。围手术期死亡1例。经术后综合治疗及随访，中位生存期为38个月。

结论

胸腺原发神经内分泌癌所致库欣综合征为一种罕见疾病，侵袭性强，目前治疗效果欠佳。早期诊断及早期治疗对临床医师而言存在很大难度，胸部增强计算机断层扫描(computed tomography, CT)是诊断并定位的重要手段，需要多种检查手段及多学科医师共同会诊并制定以手术为主的综合诊治方案。

Cushing's disease, pseudo-Cushing states and the dexamethasone test: a historical and critical review

The dexamethasone (DXM) test has been widely used for diagnosing Cushing's disease (CD). The purpose of this paper is to review its diagnostic merit based on calculation of data extracted from earlier publications. Studies presenting individual values for patients with CD and normal subjects were identified through PubMed searches and references in pertinent studies. Calculation of the retrieved data demonstrated huge variation in the relative suppressibility, negative suppression being common. Furthermore, in almost each study retrieved, the pre and post DXM values were closely correlated. Finally, the generally accepted view that DXM causes less suppression in Cushing's disease than in euadrenal controls appears unfounded. A central issue in the definition of so-called "pseudo-Cushing's states" is failure to suppress cortisol secretion with DXM. From analysis of the literature it appears quite possible that this does not reflect a specific endocrine deficit, but a physiological "stress" reaction. The above issues question the diagnostic value of the test, in particular in clinically and biochemically borderline cases.

A case of ectopic ACTH syndrome treated with intermittent administration of dopamine agonists

ACTH-dependent Cushing's syndrome includes Cushing's disease and ectopic ACTH syndrome (EAS). The differential diagnosis of Cushing's disease from EAS in cases of ACTH-dependent Cushing's syndrome is a challenging problem. We report here a case of EAS with an unknown source of ACTH secretion. Extensive imaging procedures, involving computed tomography (neck to pelvis), pituitary magnetic resonance imaging, and whole-body (18)F-fluorodeoxyglucose-positron emission tomography, failed to reveal the source of ACTH secretion. Intermittent administration of bromocriptine, a short-acting and nonselective dopamine agonist, has afforded adequate suppression of plasma ACTH and cortisol levels over the long term.

LEARNING POINTS

Tumor excision is the primary treatment for EAS. However, when surgery is impossible, medical therapy is needed to treat hypercortisolism.In cases where the source of ACTH secretion is unknown, inhibitors of steroidogenesis, such as metyrapone, mitotane, ketoconazole, and etomidate, are mostly used to suppress cortisol secretion.Medications that suppress ACTH secretion are less effective, therefore less popular, as standard treatments.In the present case, short-term treatment with dopamine agonists was effective for the long-term suppression of both ACTH and cortisol levels.

Reliability of the diagnostic tests for Cushing's syndrome performed in a tertiary referral center

The study aimed to retrospectively evaluate the reliability of the diagnostic and location tests in Cushing's Syndrome (CS). Eighty-seven patients diagnosed with CS between 1995 and 2007 by Endocrinology Metabolism Department of Cerrahpasa Medical School were included in the study. The control group consisted of 91 patients who presented to the outpatient clinic because of obesity. The diagnostic tests were as follows: 1 mg dexamethasone suppression test (DST), 24-h urinary free cortisol (UFC), midnight cortisol level (MCL), ACTH level and overnight 8 mg DST. The sensitivity and specificity of UFC were 81 and 66 % respectively for the cut-off point of 50 μg/day, whereas they were 64 and 76 % respectively for the cut-off point of 100 μg/day. For the cut-off value of 1.8/μg/dL for MCL and 1 mDST, the sensitivity rates were 100 and 98 %, while the specificity rates were 88 and 33 %, respectively. Among the location tests, the sensitivity and specificity of ACTH under 10 pg/mL for adrenal CS were 92 and 94 % respectively. The sensitivity and specificity of ACTH higher than 30 pg/mL for ACTH-dependent CS were 69 and 100 % respectively. The sensitivity rates of 8 mg DST for 50 and 60 % suppressions were 83 and 79 % respectively, whereas the specificity rates were 75 and 88 % respectively. 1 mg DST (cut-off <1.8 μg/dL) and UFC (50 μg/24 h) are appropriate tests for screening CS. Overnight 8 mg DST with 60 % suppression for Cushing's Disease (CD) and ACTH levels <10 pg/mL for adrenal CS, ACTH levels >30 pg/mL for ACTH dependency were identified as the best tests for the differential diagnosis of the subtypes.

Long-term remission and recurrence rates in Cushing's disease: predictive factors in a single-centre study

OBJECTIVE

To investigate the early and late outcomes of patients with Cushing's disease (CD) submitted to a neurosurgical procedure as first-line treatment.

DESIGN

In this single-centre retrospective case notes study, 131 patients with CD with a minimum follow-up period of 6 years (124 operated by transsphenoidal surgery (TSS) and seven by the transcranial approach) were studied. Apparent immediate cure: post-operative 0900 h serum cortisol level <50 nmol/l; remission: cortisol insufficiency or restoration of 'normal' cortisol levels with resolution of clinical features; and recurrence: dexamethasone resistance and relapse of hypercortisolaemic features.

RESULTS

In patients operated by TSS, remission of hypercortisolaemia was found in 72.8% of 103 microadenomas and 42.9% of 21 macroadenomas, with recurrence rates 22.7 and 33.3% respectively with a 15-year mean follow-up (range, 6-29 years). Of 27 patients with microadenomas operated after 1991, with positive imaging and pathology, 93% obtained remission with 12% recurrence. In multivariate analysis, the time needed to achieve recovery of hypothalamo-pituitaryadrenal axis was the only significant predictor of recurrence; all patients who recurred showed recovery within 3 years from surgery: 31.3% of patients had total hypophysectomy with no recurrence; 42% of patients with selective adenomectomy and 26.5% with hemi-hypophysectomy showed recurrence rates of 31 and 13% respectively (χ(2)=6.275, P=0.03). Strict remission criteria were not superior in terms of the probability of recurrence compared with post-operative normocortisolaemia.

CONCLUSIONS

Lifelong follow-up for patients with CD appears essential, particularly for patients who have shown rapid recovery of their axis. The strict criteria previously used for 'apparent cure' do not appear to necessarily predict a lower recurrence rate.

Clinical Characteristics of Endogenous Cushing's Syndrome at a Medical Center in Southern Taiwan

From January 1987 to December 2011, over a total of 25 years, 84 patients with Cushing's syndrome (CS) were identified at a medical center in southern Taiwan. We observed a higher incidence of ACTH-independent CS (75%) than ACTH-dependent CS (25%). A higher incidence of adrenocortical adenoma (58.3%) than Cushing's disease (CD, 21.4%) was also found. The sensitivity of the definitive diagnostic tests for CS, including loss of plasma cortisol circadian rhythm, a baseline 24 h urinary free cortisol (UFC) value >80  μ g, and overnight and 2-day low-dose dexamethasone suppression test, was between 94.4% and 100%. For the 2-day high-dose dexamethasone suppression test for the differential diagnosis of CD, the sensitivity of 0800 h plasma cortisol and 24 h UFC was 44.4% and 85.7%, respectively. For the differential diagnosis of adrenal CS, the sensitivities of the 0800 h plasma cortisol and 24 h UFC were 95.5% and 88.9%, respectively. In patients with ACTH-independent CS and ACTH-dependent CS, the baseline plasma ACTH levels were all below 29 pg/mL and above 37 pg/mL, respectively. The postsurgical hospitalization stay following retroperitoneoscopic adrenalectomy was shorter than that observed for transabdominal adrenalectomy (4.3 ± 1.6 versus 8.8 ± 3.7 days, P < 0.001). It was easy to develop retroperitoneal and peritoneal seeding of adrenocortical carcinoma via laparoscopic adrenalectomy.

The investigation of Cushing syndrome: essentials in optimizing appropriate diagnosis and management

The investigation of Cushing syndrome (CS) should start with careful history taking and clinical examination, and exogenous steroid usage must be excluded. It is essential to confirm hypercortisolism before further investigations are undertaken. The recommended first-line tests include midnight salivary cortisol and/or the 1 mg overnight or low-dose dexamethasone suppression tests. The next step is to differentiate adrenocorticotrophin (ACTH)-dependent from ACTH-independent CS by measuring ACTH. With ACTH-dependence, further investigations should differentiate pituitary-dependent from ectopic ACTH-dependent CS. Many dynamic tests may be considered, but we suggest that bilateral inferior petrosal sinus sampling should be performed in almost all patients with ACTH-dependent CS, except for patients with a pituitary macroadenoma. Imaging should include MR scanning of the pituitary, and CT scanning of the chest and abdomen to look for an ectopic source. Confirmation of the diagnosis of CS and accurate localization of its source are vital to optimize therapy for this complex disorder.

A prospective evaluation of postural stimulation testing, computed tomography and adrenal vein sampling in the differential diagnosis of primary aldosteronism

CONTEXT

In primary aldosteronism (PA), discriminating unilateral from bilateral disease is crucial because adrenalectomy is frequently curative in the former case but rarely helps in the latter. Various series have reported the utility of postural stimulation testing (PST), cross-sectional imaging and adrenal vein sampling (AVS) in the assessment of PA, but most of these studies were retrospective.

OBJECTIVE

To prospectively determine the diagnostic utility of PST, AVS and computed tomography (CT) using a radiological scoring system in the assessment of PA in a tertiary centre, as well as to document the incidence of autonomous cortisol cosecretion.

DESIGN AND SETTING

Fifty consecutive patients with PA underwent PST, CT, AVS and a low-dose dexamethasone suppression test with measurement of serum cortisol at 48 h. For patients who underwent surgery, histological confirmation, and a normal postoperative serum aldosterone concentration and plasma renin activity were taken as evidence for unilateral disease. For other patients, results from successful adrenal vein sampling were the diagnostic evidence against which CT and PST were assessed.

RESULTS

Postural stimulation testing had a sensitivity and specificity of 44-56% and 71-75%, respectively. CT had an overall sensitivity and specificity of 77% and 80%, respectively, rising to 100% sensitivity and specificity if there was a single, discrete macronodule with an unequivocally normal contralateral gland. Evidence of cosecretion of cortisol occurred in 14% of patients.

CONCLUSIONS

Preliminary experience is presented of an objective radiological scoring system for selecting patients with PA for AVS. PST provides little, if any, useful additional information. A significant minority of patients with PA exhibit evidence of cortisol cosecretion, which may have implications for perioperative management.

Ectopic adrenocorticotropic hormone syndrome: a diagnostic challenge and review of the literature

We present a case of a 60-year-old woman who initially presented with pneumonia and abdominal pain and was diagnosed with ectopic adrenocorticotropic hormone (ACTH) syndrome secondary to small cell lung cancer. We review published literature and summarize the typical challenges in the diagnosis and treatment of ectopic ACTH syndrome. Recent research has shed new light on the mechanism of ectopic ACTH production and provided a potential new target for treatment.

Comparisons in the epidemiology, diagnostic features and cure rate by transsphenoidal surgery between paediatric and adult-onset Cushing's disease

OBJECTIVE

There are few published comparisons between paediatric and adult-onset Cushing's disease (CD). We compare the epidemiology, diagnostic features and cure rate by transsphenoidal surgery (TSS) in these groups.

DESIGN

Retrospective review of patient databases in a single university hospital centre.

PATIENTS

Totally, 41 paediatric (mean age 12.3 ± 3.5 years; range 5.7-17.8) and 183 adult (mean age 40 ± 13 years; range 18.0-95.0) patients with CD were investigated.

RESULTS

Paediatric CD was characterised by male (63%) and adult CD by a female predominance (79%, P<0.0001). There were small but significant differences in clinical presentation. Biochemical features of CD were comparable except the serum cortisol increase during a CRH test: mean change (105%, n=39) in paediatric and (54%, n=123) in adult subjects (P<0.0001). Macroadenomas were more common in adult (15%, 28/183) than in paediatric (2%, 1/41, P=0.04) CD. Corticotroph microadenomas were more easily visualised by pituitary magnetic resonance imaging (MRI) in adult (76%, 50/66) compared with paediatric (55%, 21/38, P=0.045) CD with poorer concordance of imaging with surgical findings in children (P=0.058). The incidence of ACTH lateralisation by bilateral simultaneous inferior petrosal sinus sampling was comparable in paediatric (76%, 25/33) and adult (79%, 46/58; P=0.95) patients with good surgical concordance in both (82% paediatric and 79% adult). Cure rates by TSS were comparable, with a paediatric cure rate of 69%.

CONCLUSION

Several features of paediatric CD are distinct: increased frequency of prepubertal CD in males, the different clinical presentation, the decreased presence of macroadenomas and the frequent absence of radiological evidence of an adenoma on MRI.