Cushing's disease: pathobiology, diagnosis, and management

Identifying gray matter alterations in Cushing's disease using machine learning: An interpretable approach

BACKGROUND

Cushing's Disease (CD) is a rare clinical syndrome characterized by excessive secretion of adrenocorticotrophic hormone, leading to significant functional and structural brain alterations as observed in Magnetic Resonance Imaging (MRI). While traditional statistical analysis has been widely employed to investigate these MRI changes in CD, it has lacked the ability to predict individual-level outcomes.

PURPOSE

To address this problem, this paper has proposed an interpretable machine learning (ML) framework, including model-level assessment, feature-level assessment, and biology-level assessment to ensure a comprehensive analysis based on structural MRI of CD.

METHODS

The ML framework has effectively identified the changes in brain regions in the stage of model-level assessment, verified the effectiveness of these altered brain regions to predict CD from normal controls in the stage of feature-level assessment, and carried out a correlation analysis between altered brain regions and clinical symptoms in the stage of biology-level assessment.

RESULTS

The experimental results of this study have demonstrated that the Insula, Fusiform gyrus, Superior frontal gyrus, Precuneus, and the opercular portion of the Inferior frontal gyrus of CD showed significant alterations in brain regions. Furthermore, our study has revealed significant correlations between clinical symptoms and the frontotemporal lobes, insulin, and olfactory cortex, which also have been confirmed by previous studies.

CONCLUSIONS

The ML framework proposed in this study exhibits exceptional potential in uncovering the intricate pathophysiological mechanisms underlying CD, with potential applicability in diagnosing other diseases.

Bone Morphogenetic Protein Signaling Agonist SB4 (BMPSB4) Inhibits Corticotroph Pituitary Neuroendocrine Tumors by Activation of Autophagy via a BMP4/SMADs-Dependent Pathway

Corticotroph pituitary neuroendocrine tumors (PitNETs), associated with Cushing's disease (CD), have limited treatment options other than surgical resection. Bone morphogenetic protein 4 (BMP4), a potential therapeutic target, is decreased in patients with CD. Previous studies have identified BMPSB4 as a potent agonist of the BMP4 signaling pathway. Here, we investigated the effect of BMPSB4 on the corticotroph PitNET cell line AtT20/D16v-F2 and explored the underlying mechanisms and therapeutic potential. We verified the low expression patterns of BMP4 and downstream p-SMAD1/5/9 in CD samples at the transcriptional and protein levels. In addition, BMPSB4 activated SMAD1/5/9 in a time- and concentration-dependent manner, with concomitant inhibitory effects on AtT20/D16v-F2 cells. Further RNA sequencing, transmission electron microscopy (TEM), and transfection with the mRFP-EGFP-LC3 adenoviral vector revealed that BMPSB4 induced cellular autophagy, which was the basis for the inhibitory effect of BMPSB4. Moreover, we demonstrated that autophagy induced by BMPSB4 was achieved through the SMADs-dependent pathway. In vivo, BMPSB4 inhibited tumor growth and significantly reduced adrenocorticotrophin (ACTH) and corticosterone (CORT) secretion, thereby alleviating the CD phenotype. In conclusion, this study identified BMPSB4 as an effective therapeutic agent for CD. BMPSB4 activates autophagy through a SMADs-dependent pathway, which in turn promotes autophagy-mediated cell death. Our work further elucidates the mechanism of the BMP4 signaling pathway in CD and suggests broad prospects for the development and application of BMPSB4 in CD therapy.

Impact of Frailty on Surgical Outcomes of Patients With Cushing Disease Using the Multicenter Registry of Adenomas of the Pituitary and Related Disorders Registry

BACKGROUND AND OBJECTIVES

Despite growing interest in how patient frailty affects outcomes (eg, in neuro-oncology), its role after transsphenoidal surgery for Cushing disease (CD) remains unclear. We evaluated the effect of frailty on CD outcomes using the Registry of Adenomas of the Pituitary and Related Disorders (RAPID) data set from a collaboration of US academic pituitary centers.

METHODS

Data on consecutive surgically treated patients with CD (2011-2023) were compiled using the 11-factor modified frailty index. Patients were classified as fit (score, 0-1), managing well (score, 2-3), and mildly frail (score, 4-5). Univariable and multivariable analyses were conducted to examine outcomes.

RESULTS

Data were analyzed for 318 patients (193 fit, 113 managing well, 12 mildly frail). Compared with fit and managing well patients, mildly frail patients were older (mean ± SD 39.7 ± 14.2 and 48.9 ± 12.2 vs 49.4 ± 8.9 years, P < .001) but did not different by sex, race, and other factors. They had significantly longer hospitalizations (3.7 ± 2.0 and 4.5 ± 3.5 vs 5.3 ± 3.5 days, P = .02), even after multivariable analysis (β = 1.01, P = .007) adjusted for known predictors of prolonged hospitalization (age, Knosp grade, surgeon experience, American Society of Anesthesiologists grade, complications, frailty). Patients with mild frailty were more commonly discharged to skilled nursing facilities (0.5% [1/192] and 4.5% [5/112] vs 25% [3/12], P < .001). Most patients underwent gross total resection (84.4% [163/193] and 79.6% [90/113] vs 83% [10/12]). No difference in overall complications was observed; however, venous thromboembolism was more common in mildly frail (8%, 1/12) than in fit (0.5%, 1/193) and managing well (2.7%, 3/113) patients (P = .04). No difference was found in 90-day readmission rates.

CONCLUSION

These results demonstrate that mild frailty predicts CD surgical outcomes and may inform preoperative risk stratification. Frailty-influenced outcomes other than age and tumor characteristics may be useful for prognostication. Future studies can help identify strategies to reduce disease burden for frail patients with hypercortisolemia.

7T MRI for Cushing Disease: A Single-Institution Experience and Literature Review

BACKGROUND AND PURPOSE

Cushing disease is typically caused by a pituitary adenoma that frequently is small and challenging to detect on conventional MR imaging. High-field-strength 7T MR imaging can leverage increased SNR and contrast-to-noise ratios compared with lower-field-strength MR imaging to help identify small pituitary lesions. We aimed to describe our institutional experience with 7T MR imaging in patients with Cushing disease and perform a review of the literature.

MATERIALS AND METHODS

We performed a retrospective analysis of 7T MR imaging findings in patients with pathology-proved Cushing disease from a single institution, followed by a review of the literature on 7T MR imaging for Cushing disease.

RESULTS

Our institutional experience identified Cushing adenomas in 10/13 (76.9%) patients on 7T; however, only 5/13 (38.5%) lesions were discrete. Overall, the imaging protocols used were heterogeneous in terms of contrast dose as well as type of postcontrast T1-weighted sequences (dynamic, 2D versus 3D, and type of 3D sequence). From our institutional data, specific postgadolinium T1-weighted sequences were helpful in identifying a surgical lesion as follows: dynamic contrast-enhanced, 2/7 (28.6%); 2D FSE, 4/8 (50%); 3D sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE), 5/6 (83.3%); and 3D MPRAGE, 8/11 (72.7%). The literature review identified Cushing adenomas in 31/33 (93.9%) patients on 7T.

CONCLUSIONS

7T MR imaging for pituitary lesion localization in Cushing disease is a new technique with imaging protocols that vary widely. Further comparative research is needed to identify the optimal imaging technique as well as assess the benefit of 7T over lower-field-strength MR imaging.

Predictors of Durable Remission After Successful Surgery for Cushing Disease: Results From the Multicenter RAPID Registry

BACKGROUND AND OBJECTIVE

Cushing disease (CD) affects mortality and quality of life along with limited long-term remission, underscoring the need to better identify recurrence risk. The identification of surgical or imaging predictors for CD remission after transsphenoidal surgery has yielded some inconsistent results and has been limited by single-center, single-surgeon, or meta-analyses studies. We sought to evaluate the multicenter Registry of Adenomas of the Pituitary and Related Disorders (RAPID) database of academic US pituitary centers to assess whether robust nonhormonal recurrence predictors could be elucidated.

METHODS

Patients with treated CD from 2011 to 2023 were included. The perioperative and long-term characteristics of CD patients with and without recurrence were assessed using univariable and multivariable analyses.

RESULTS

Of 383 patients with CD from 26 surgeons achieving postoperative remission, 288 (75.2%) maintained remission at last follow-up while 95 (24.8%) showed recurrence (median time to recurrence 9.99 ± 1.34 years). Patients with recurrence required longer postoperative hospital stays (5 ± 3 vs 4 ± 2 days, P = .002), had larger average tumor volumes (1.76 ± 2.53 cm3 vs 0.49 ± 1.17 cm3, P = .0001), and more often previously failed prior treatment (31.1% vs 14.9%, P = .001) mostly being prior surgery. Multivariable hazard prediction models for tumor recurrence found younger age (odds ratio [OR] = 0.95, P = .002) and Knosp grade of 0 (OR = 0.09, reference Knosp grade 4, P = .03) to be protective against recurrence. Comparison of Knosp grade 0 to 2 vs 3 to 4 showed that lower grades had reduced risk of recurrence (OR = 0.27, P = .04). Other factors such as length of stay, surgeon experience, prior tumor treatment, and Knosp grades 1, 2, or 3 failed to reach levels of statistical significance in multivariable analysis.

CONCLUSION

This multicenter study centers suggests that the strongest predictors of recurrence include tumor size/invasion and age. This insight can help with patient counseling and prognostication. Long-term follow-up is necessary for patients, and early treatment of small tumors may improve outcomes.

HOW I DO IT: Cushing's disease-selective adenomectomy via an endoscopic transsphenoidal approach

BACKGROUND

An ACTH-secreting pituitary adenoma is the most common cause of excessive endogenous glucocorticoid production resulting in Cushing's Syndrome. A multidisciplinary approach is paramount. Selective adenomectomy is the treatment of choice.

METHOD

Endoscopic transnasal transsphenoidal approach to the tumour, along with techniques for resection, are demonstrated.

CONCLUSION

Endoscopic transsphenoidal approaches with its magnified view of the pituitary gland allows precise microsurgical dissection during selective adenomectomy. This technique increases the possibility of proving a gross total resection, leading to clinical and biochemical cure in these patients.

Three-Dimensional Fast Spin Echo Pituitary MRI in Treatment-Naïve Cushing's Disease: Reduced Impact of Reader Experience and Increased Diagnostic Accuracy

BACKGROUND

In patients with Cushing's disease, the preoperative identification of pituitary adenomas is crucial to treatment. However, increasing diagnostic accuracy remains an unresolved issue.

PURPOSE

To evaluate the diagnostic accuracy and the impact of readers' experience regarding high-resolution contrast-enhanced magnetic resonance imaging (hrMRI) for identifying pituitary adenomas in comparison with conventional contrast-enhanced MRI (cMRI) and dynamic contrast-enhanced MRI (dMRI).

STUDY TYPE

Retrospective.

POPULATION

Sixty-five patients (median age, 39 years; interquartile range [IQR], 28-53 years; 60% females) with treatment-naïve Cushing's disease.

FIELD STRENGTH/SEQUENCE

3-T, seven fast spin echo sequences.

ASSESSMENT

The diagnostic accuracies of identifying pituitary adenomas on cMRI, dMRI, combined cMRI and dMRI (cdMRI), and hrMRI were independently evaluated by six readers with three experience levels (high: >20 years, modest: 10-20 years, low: <10 years; two readers for each experience level). Readers were asked to localize the lesion, and measure its diameter on the sequence where identified. The reference standard was postoperative histopathology. The impact of readers' experience and interobserver agreement were assessed. Image quality was assessed using a 5-point Likert scale, including overall image quality, sharpness, and structural conspicuity.

STATISTICAL TESTS

McNemar's test, Cochran's test, Wilcoxon signed-rank test, Mann-Whitney U test, and κ statistics for interobserver agreement. A P-value <0.05 was considered statistically significant.

RESULTS

For identifying pituitary adenomas (median diameter, 5 mm; IQR, 4-5 mm), hrMRI had significantly higher sensitivity (87.7%-93.8%) than cMRI, dMRI, and cdMRI (52.3%-75.4%) for readers with different experience levels. The interobserver agreement was moderate (κ = 0.461-0.523). The sensitivity for hrMRI was comparable between readers with different experience levels (P = 0.371). All image quality scores on hrMRI were significantly higher than cMRI and dMRI (5.0 vs. 4.0).

DATA CONCLUSION

For identifying pituitary adenomas in patients with treatment-naïve Cushing's disease, hrMRI may show high diagnostic accuracy and seems not to be affected by readers' experience.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Epigenetic Mechanisms Modulated by Glucocorticoids With a Focus on Cushing Syndrome

In Cushing syndrome (CS), prolonged exposure to high cortisol levels results in a wide range of devastating effects causing multisystem morbidity. Despite the efficacy of treatment leading to disease remission and clinical improvement, hypercortisolism-induced complications may persist. Since glucocorticoids use the epigenetic machinery as a mechanism of action to modulate gene expression, the persistence of some comorbidities may be mediated by hypercortisolism-induced long-lasting epigenetic changes. Additionally, glucocorticoids influence microRNA expression, which is an important epigenetic regulator as it modulates gene expression without changing the DNA sequence. Evidence suggests that chronically elevated glucocorticoid levels may induce aberrant microRNA expression which may impact several cellular processes resulting in cardiometabolic disorders. The present article reviews the evidence on epigenetic changes induced by (long-term) glucocorticoid exposure. Key aspects of some glucocorticoid-target genes and their implications in the context of CS are described. Lastly, the effects of epigenetic drugs influencing glucocorticoid effects are discussed for their ability to be potentially used as adjunctive therapy in CS.

Analysis of brain structural covariance network in Cushing disease

Background

Cushing disease (CD) is a rare clinical neuroendocrine disease. CD is characterized by abnormal hypercortisolism induced by a pituitary adenoma with the secretion of adrenocorticotropic hormone. Individuals with CD usually exhibit atrophy of gray matter volume. However, little is known about the alterations in topographical organization of individuals with CD. This study aimed to investigate the structural covariance networks of individuals with CD based on the gray matter volume using graph theory analysis.

Methods

High-resolution T1-weighted images of 61 individuals with CD and 53 healthy controls were obtained. Gray matter volume was estimated and the structural covariance network was analyzed using graph theory. Network properties such as hubs of all participants were calculated based on degree centrality.

Results

No significant differences were observed between individuals with CD and healthy controls in terms of age, gender, and education level. The small-world features were conserved in individuals with CD but were higher than those in healthy controls. The individuals with CD showed higher global efficiency and modularity, suggesting higher integration and segregation as compared to healthy controls. The hub nodes of the individuals with CD were Short insular gyri (G_insular_short_L), Anterior part of the cingulate gyrus and sulcus (G_and_S_cingul-Ant_R), and Superior frontal gyrus (G_front_sup_R).

Conclusions

Significant differences in the structural covariance network of patients with CD were found based on graph theory. These findings might help understanding the pathogenesis of individuals with CD and provide insight into the pathogenesis of this CD.

The diagnostic yield of inferior petrosal sinus sampling in Cushing syndrome in the era of ovine CRH shortage

PURPOSE

The ovine corticotropin-releasing hormone (oCRH) stimulation test has been routinely used in the diagnostic work-up of ACTH-dependent Cushing syndrome (CS). With oCRH currently being out-of-stock in Europe, we aimed at evaluating the diagnostic performance of inferior petrosal sinus sampling (IPSS) without oCRH stimulation.

METHODS

We compared the values of 40 patients with ACTH-dependent CS and negative MRI findings in whom ACTH was measured before and after oCRH stimulation.

RESULTS

The ratio of central-to-peripheral ACTH measurement (IPS:P) before the combined 3, 5, and 10 min of oCRH stimulation yielded diminished sensitivity (85% vs. 97%), alongside markedly decreased specificity (57% vs. 71%), as well as reduced positive and negative predictive values (90% vs. 94% and 44% vs. 83%), respectively.

CONCLUSIONS

With the current drug shortages in Europe, ACTH measurements without oCRH stimulation in IPSS cannot be recommended. Thus, we call for desmopressin or the commercially available human CRH as a potential alternative in the confirmation of ACTH excess by IPSS in equivocal MRI findings.

Autoimmune Disorders Associated With Surgical Remission of Cushing's Disease : A Cohort Study

BACKGROUND

Glucocorticoids suppress inflammation. Autoimmune disease may occur after remission of Cushing's disease (CD). However, the development of autoimmune disease in this context is not well described.

OBJECTIVE

To determine 1) the incidence of autoimmune disease in patients with CD after surgical remission compared with patients with nonfunctioning pituitary adenomas (NFPAs) and 2) the clinical presentation of and risk factors for development of autoimmune disease in CD after remission.

DESIGN

Retrospective matched cohort analysis.

SETTING

Academic medical center/pituitary center.

PATIENTS

Patients with CD with surgical remission and surgically treated NFPA.

MEASUREMENTS

Cumulative incidence of new-onset autoimmune disease at 3 years after surgery. Assessment for hypercortisolemia included late-night salivary cortisol levels, 24-hour urine free cortisol (UFC) ratio (UFC value divided by the upper limit of the normal range for the assay), and dexamethasone suppression tests.

RESULTS

Cumulative incidence of new-onset autoimmune disease at 3 years after surgery was higher in patients with CD (10.4% [95% CI, 5.7% to 15.1%]) than in those with NFPAs (1.6% [CI, 0% to 4.6%]) (hazard ratio, 7.80 [CI, 2.88 to 21.10]). Patients with CD showed higher prevalence of postoperative adrenal insufficiency (93.8% vs. 16.5%) and lower postoperative nadir serum cortisol levels (63.8 vs. 282.3 nmol/L) than patients with NFPAs. Compared with patients with CD without autoimmune disease, those who developed autoimmune disease had a lower preoperative 24-hour UFC ratio (2.7 vs. 6.3) and a higher prevalence of family history of autoimmune disease (41.2% vs. 20.9%).

LIMITATION

The small sample of patients with autoimmune disease limited identification of independent risk factors.

CONCLUSION

Patients achieving surgical remission of CD have higher incidence of autoimmune disease than age- and sex-matched patients with NFPAs. Family history of autoimmune disease is a potential risk factor. Adrenal insufficiency may be a trigger.

PRIMARY FUNDING SOURCE

Recordati Rare Diseases Inc.

Overweight and obesity in children and adolescents with endocrine disorders

Obesity has become a serious medical condition where many factors can contribute to excess weight gain. The most common type of childhood obesity is simple obesity, which is due to gene-obesogenic environment interaction. Only a minority are due to pathological causes. Secondary causes of obesity, while less common, include these: genetic syndromes, drug-related obesity, as well as endocrine disorders (hypothyroidism, Cushing's syndrome, growth hormone deficiency, hypogonadism, pseudohypoparathyroidism type Ia, insulinoma, hypothalamic obesity and polycystic ovary syndrome). Given that some conditions may be treatable, physicians must be aware of obesity due to endocrinopathies and distinguish them from simple obesity, and treat them properly. Although rare among children, early detection of the endocrine cause of obesity leads to reduced morbidity and, in some cases, reduced mortality in these individuals. The aim of this review is to summarize the current findings on obesity-related endocrinopathies in children (illustrated by clinical examples), highlighting aspects of pathogenetic mechanisms, genetics, the clinical diagnosis, growth, body mass index and possible therapeutic approaches. Early detection and correction of endocrine obesity is of paramount importance for obese children who could benefit from timely diagnosis and an improved management of obesity as many disturbances related to obesity can be reversed at the early stage, if weight loss is achieved.

Blood concentrations of anterior pituitary hormones in drug-naïve people with first-episode psychosis: A systematic review and meta-analysis

INTRODUCTION

The role of anterior pituitary hormones - i.e., adrenocorticotropic hormone (ACTH), luteinizing and follicle stimulating hormones (LH and FSH), growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone (TSH) - in early schizophrenia and psychoses unclear. We thus performed a systematic review and meta-analysis on the blood concentrations of ACTH, LH and FSH, GH, PRL, and TSH in drug-naïve people with first-episode psychosis (FEP) as compared with healthy controls.

METHODS

We searched Embase, MEDLINE, and PsycInfo for articles indexed until September 2022. Data quality was appraised. Random-effects meta-analyses were carried out, generating pooled standardized mean differences (SMDs). Between-study heterogeneity was estimated using the I2 statistic. Sensitivity and meta-regression analyses were performed.

RESULTS

Twenty-six studies were included. Drug-naïve people with FEP, compared to healthy subjects, had higher blood concentrations of ACTH (k = 7; N = 548; SMD = 0.62; 95%CI: 0.29 to 0.94; p < 0.001; I2 = 60.9%) and PRL (k = 17; N = 1757; SMD = 0.85; 95%CI: 0.56 to 1.14; p < 0.001; I2 = 85.5%) as well as lower levels of TSH (k = 6; N = 677; SMD = -0.34; 95%CI: -0.54 to -0.14; p = 0.001; I2 = 29.1%). Meta-regressions did not show any moderating effect of age (p = 0.78), sex (p = 0.21), or symptom severity (p = 0.87) on PRL concentrations in drug-naïve FEP. Available data were not sufficient to perform meta-analyses on FSH, LH, and GH.

CONCLUSIONS

Drug-naïve people with FEP have altered ACTH, PRL, and TSH blood concentrations, supporting the hypothesis that an abnormal anterior pituitary hormone secretion may be involved in the onset of schizophrenia and psychoses. Further research is needed to elucidate the role of pituitary hormones in FEP.

Current and Future Perspectives of Microscopic and Endoscopic Transsphenoidal Surgery for Pituitary Adenomas: A Narrative Review

Transsphenoidal resection remains the standard treatment for most pituitary adenomas. However, the ideal surgical approach to safely access these lesions, either microsurgical or endoscopic, continues to be debated. Since the introduction of endoscopic transsphenoidal surgery, centers around the world have increasingly adopted this technique, experiencing a shift away from the conventional microsurgical approach. Large series reporting the efficacy and safety of endoscopic surgery have fueled a growing interest in comparing clinical outcomes between both approaches. Still, proving superiority of either surgical approach remains an elusive task due to the inherent drawbacks of surgical observational studies, as we are still faced with a growing body of evidence reporting conflicting results. Thus, a comprehensive discussion regarding the reach and limitations of both techniques becomes necessary. In this narrative review, we perform a critical appraisal of the literature and provide an expert opinion on the state-of-the-art in transsphenoidal surgery for pituitary adenomas. The advantages and limitations of each approach are assessed and compared from a technical standpoint, and their reported outcomes evaluated in the framework of this transition phase. Available evidence should be interpreted in light of individual patient characteristics and within the context of each medical center, taking into consideration the known impact that surgical expertise and multidisciplinary management hold on clinical outcomes.

Non-Invasive Biochemical Testing of ACTH-dependent Cushing's Disease: Do We Still Need Petrosal Sinus Sampling?

Differentiating between a pituitary from an ectopic source of ACTH could be a real one of the major challenges of clinical endocrinology. The Bilateral inferior petrosal sinus sampling (BIPSS) is considered the gold standard for identifying the source of ACTH; however, is not available worldwide. After the SARS-CoV-2 pandemic, algorithms that include biochemical and imaging tests have gained importance as an alternative to BIPSS. This review summarizes the drawbacks in the differential diagnosis of ACTH-dependent Cushing; the evolution of diagnostic tests, and the evidence that exists on their performance. As well as a comparison between the advantages and disadvantages of invasive and non-invasive tests.

Rathke's cleft cysts causing Cushing's disease: Two unique cases and review of the literature

Background

The presentation of isolated Rathke's cleft cysts (RCC) without any associated pituitary adenoma in patients with symptoms consistent with Cushing's disease (CD) remains exceedingly rare. As such, we aim to present two cases of RCC presenting with CD with a resultant resolution of their CD following surgical resection.

Case Description

Here, we present two cases of RCCs presenting with symptoms suggestive of CD. A functional pituitary microadenoma was the presumed diagnosis based on initial clinical presentation and diagnostic imaging suggesting a pituitary lesion. However, pathology results demonstrated no evidence of adenoma but cysts lined with columnar epithelia consistent with RCC. Complete surgical resection was achieved in both patients through endoscopic endonasal pituitary resection with postoperative symptomatic resolution and normalization of cortisol levels. In addition, we discuss the literature on this rare presentation and suggest a pathological mechanism for this unique presentation of RCC-causing CD.

Conclusion

Surgical resection of RCC may provide a "biochemical cure" for patients presenting with CD, as demonstrated by these two unique cases. The clinical features, histological findings, and possible pathological mechanisms for this unique presentation of RCC causing CD discussed lay the groundwork for future studies into the pathophysiology of RCC and CD.

Postoperative Serum Cortisol and Cushing Disease Recurrence in Patients With Corticotroph Adenomas

CONTEXT

In Cushing disease, the association between the rate of serum cortisol decline and recurrent disease after corticotroph adenoma removal has not been adequately characterized.

OBJECTIVE

To analyze postoperative serum cortisol and recurrence rates in Cushing disease.

METHODS

Patients with Cushing disease and pathology-confirmed corticotroph adenoma were retrospectively studied. Cortisol halving time was estimated using exponential decay modeling. Halving time, first postoperative cortisol, and nadir cortisol values were collected using immediate postoperative inpatient laboratory data. Recurrence and time-to-recurrence were estimated and compared among cortisol variables.

RESULTS

A total of 320 patients met inclusion/exclusion criteria for final analysis, and 26 of those patients developed recurrent disease. Median follow-up time was 25 months (95% CI, 19-28 months), and 62 patients had ≥ 5 years follow-up time. Higher first postoperative cortisol and higher nadir were associated with increased risk of recurrence. Patients who had a first postoperative cortisol ≥ 50 µg/dL were 4.1 times more likely to recur than those with a first postoperative cortisol < 50 µg/dL (HR 4.1, 1.8-9.2; P = .0003). Halving time was not associated with recurrence (HR 1.7, 0.8-3.8, P = .18). Patients with a nadir cortisol ≥2 µg/dL were 6.6 times more likely to recur than those with a nadir cortisol of < 2 µg/dL (HR 6.6, 2.6-16.6, P < .0001).

CONCLUSION

Postoperative nadir serum cortisol is the most important cortisol variable associated with recurrence and time-to-recurrence. Compared to first postoperative cortisol and cortisol halving time, a nadir < 2 µg/dL showed the strongest association with long-term remission and typically occurs within the first 24 to 48 hours after surgery.

An individualized approach to the management of Cushing disease

Cushing disease caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary corticotroph adenoma leads to hypercortisolaemia with high mortality due to metabolic, cardiovascular, immunological, neurocognitive, haematological and infectious conditions. The disorder is challenging to diagnose because of its common and heterogenous presenting features and the biochemical pitfalls of testing levels of hormones in the hypothalamic-pituitary-adrenal axis. Several late-night salivary cortisol and 24-h urinary free cortisol tests are usually required as well as serum levels of cortisol after a dexamethasone suppression test. MRI might only identify an adenoma in 60-75% of patients and many adenomas are small. Therefore, inferior petrosal sinus sampling remains the gold standard for confirmation of ACTH secretion from a pituitary source. Initial treatment is usually transsphenoidal adenoma resection, but preoperative medical therapy is increasingly being used in some countries and regions. Other management approaches are required if Cushing disease persists or recurs following surgery, including medications to modulate ACTH or block cortisol secretion or actions, pituitary radiation, and/or bilateral adrenalectomy. All patients require lifelong surveillance for persistent comorbidities, clinical and biochemical recurrence, and treatment-related adverse effects (including development of treatment-associated hypopituitarism). In this Review, we discuss challenges in the management of Cushing disease in adults and provide information to guide clinicians when planning an integrated and individualized approach for each patient.

Supervised machine learning to validate a novel scoring system for the prediction of disease remission of functional pituitary adenomas following transsphenoidal surgery

Functional pituitary adenomas (FPAs) are associated with hormonal hypersecretion resulting in systemic endocrinopathies and increased mortality. The heterogenous composition of the FPA population has made modeling predictive factors of postoperative disease remission a challenge. Here, we aim to define a novel scoring system predictive of disease remission following transsphenoidal surgery (TSS) for FPAs and validate our process using supervised machine learning (SML). 392 patients with FPAs treated at one of the three Mayo Clinic campuses were retrospectively reviewed. Variables found significant on multivariate analysis were incorporated into our novel Pit-SCHEME score. The Pit-SCHEME score with a cut-off value ≥ 6 achieved a sensitivity of 86% and positive likelihood ratio of 2.88. In SML models, without the Pit-SCHEME score, the k-nearest neighbor (KNN) model achieved the highest accuracy at 75.6%. An increase in model sensitivity was achieved with inclusion of the Pit-SCHEME score with the linear discriminant analysis (LDA) model achieving an accuracy of 86.9%, which suggests the Pit-SCHEME score is the variable of most importance for prediction of postoperative disease remission. Ultimately, these results support the potential clinical utility of the Pit-SCHEME score and its prospective future for aiding in the perioperative decision making in patients with FPAs.

High-resolution contrast-enhanced MRI with three-dimensional fast spin echo improved the diagnostic performance for identifying pituitary microadenomas in Cushing's syndrome

OBJECTIVES

To assess the diagnostic performance of high-resolution contrast-enhanced MRI (hrMRI) with three-dimensional (3D) fast spin echo (FSE) sequence by comparison with conventional contrast-enhanced MRI (cMRI) and dynamic contrast-enhanced MRI (dMRI) with 2D FSE sequence for identifying pituitary microadenomas.

METHODS

This single-institutional retrospective study included 69 consecutive patients with Cushing's syndrome who underwent preoperative pituitary MRI, including cMRI, dMRI, and hrMRI, between January 2016 to December 2020. Reference standards were established by using all available imaging, clinical, surgical, and pathological resources. The diagnostic performance of cMRI, dMRI, and hrMRI for identifying pituitary microadenomas was independently evaluated by two experienced neuroradiologists. The area under the receiver operating characteristics curves (AUCs) were compared between protocols for each reader by using the DeLong test to assess the diagnostic performance for identifying pituitary microadenomas. The inter-observer agreement was assessed by using the κ analysis.

RESULTS

The diagnostic performance of hrMRI (AUC, 0.95-0.97) was higher than cMRI (AUC, 0.74-0.75; p ≤ .002) and dMRI (AUC, 0.59-0.68; p ≤ .001) for identifying pituitary microadenomas. The sensitivity and specificity of hrMRI were 90-93% and 100%, respectively. There were 78% (18/23) to 82% (14/17) of the patients, who were misdiagnosed on cMRI and dMRI and correctly diagnosed on hrMRI. The inter-observer agreement for identifying pituitary microadenomas was moderate on cMRI (κ = 0.50), moderate on dMRI (κ = 0.57), and almost perfect on hrMRI (κ = 0.91), respectively.

CONCLUSIONS

The hrMRI showed higher diagnostic performance than cMRI and dMRI for identifying pituitary microadenomas in patients with Cushing's syndrome.

KEY POINTS

• The diagnostic performance of hrMRI was higher than cMRI and dMRI for identifying pituitary microadenomas in Cushing's syndrome. • About 80% of patients, who were misdiagnosed on cMRI and dMRI, were correctly diagnosed on hrMRI. • The inter-observer agreement for identifying pituitary microadenomas was almost perfect on hrMRI.

Nelson's Syndrome: A Narrative Review

Nelson's syndrome (NS) is an uncommon disease occurring as a complication of bilateral adrenalectomy (BLA) in patients with persistent Cushing's disease (CD) due to an adrenocorticotropin-producing pituitary tumor. The first reports of this syndrome were done in the 50s, although its pathophysiology is still not understood. Every year, between 1.8 and 2.6 cases are thought to occur per million people. It is characterized by hyperpigmentation, elevated adrenocorticotropic hormone (ACTH) plasma levels, and typical signs and symptoms related to pituitary adenomas, such as visual deficits due to optic pathway compression or decreased hormone production from the adenohypophysis. NS represents a challenge due to the lack of accepted diagnostic criteria and the complexity of its treatment. Moreover, the development of stereotactic radiosurgery (SRS) in the last few years has become an essential but controversial strategy for this syndrome. This review presents a comprehensive overview of NS.

Double Pituitary Adenomas in Patients With Cushing's Disease

Background and objective Double and multiple pituitary adenomas (PAs) are discovered in 2.6-3.3% of patients with Cushing's disease and in approximately 1% of autopsies. Undiagnosed and unremoved second PA may be the cause of unsuccessful surgical treatment of Cushing's disease. In this study, we aimed to describe our experience with the detection and treatment of patients with double PAs. Methods All patients in our series underwent transsphenoidal surgery (TSS) with endoscopic and neuronavigation assistance. Before 2017, we completely relied on MRI findings while planning surgery. From 2017 onwards, a broad revision of the sella turcica was conducted during surgeries regardless of the MRI data. Results Overall, 81 patients were included in the study: 51 before 2017 and 30 in 2017 after. In the pre-2017 group of patients, three out of 51 had double adenomas, and all of them were seen on MRI images. We encountered four more double PAs during the next period. Only two of them had been predicted by MRI. The remission rate was higher after 2017 and amounted to 90% (27 out of 30 patients). In contrast, before the implementation of total revision (pre-2017), our success rate was 82% (42 out of 51 cases). Both neoplasms in cases of double PAs yielded similar histological and immunohistochemical (IHC) features but were consistent with multiple PAs. Conclusions Although the improvement in our results in recent years cannot be clearly attributed to a targeted search for the second microadenoma, we still recommend performing a broad inspection of the sella turcica after the excision of the pituitary microadenoma regardless of preoperative MRI data.

Intraoperative Predictor of Remission in Cushing Disease

BACKGROUND

Cushing disease represents a challenge for neurosurgeons, with high recurrence rates reported. Characteristics associated with remission are incompletely understood; thus, an intraoperative predictor for outcome would be valuable for assessing resection of adrenocorticotropic hormone (ACTH) secreting tissue.

OBJECTIVE

To evaluate whether intraoperative ACTH measurement could predict outcome after surgery for Cushing disease.

METHODS

Retrospective cohort study of 55 consecutive encounters with Cushing disease who had peripheral plasma ACTH levels measured intraoperatively before, during, and after tumor resection. The primary outcome measure was remission, defined by either 2 negative 24-hour urine free cortisol or 2 negative midnight salivary cortisol measurements. A logistic regression machine learning model was generated using recursive feature elimination.

RESULTS

Fifty-five operative encounters, comprising 49 unique patients, had a mean follow-up of 2.73 years (±2.11 years) and a median follow-up of 2.07 years. Remission was achieved in 69.1% (n = 38) of all operations and in 78.0% (n = 32) of those without cavernous sinus invasion. The final ACTH level measured intraoperatively correctly predicted outcome (area under the curve = 0.766; P value = .002). The odds ratio of remission in patients with the lowest quartile vs highest quartile final intraoperative ACTH was 23.4 ( P value = .002). Logistic regression machine learning model resulted in incorporating postoperative day 1 morning cortisol, final intraoperative ACTH that predicted outcome with an average area under the curve of 0.80 ( P = .0027).

CONCLUSION

Intraoperative ACTH may predict outcome after surgery in Cushing disease; furthermore, investigation is warranted.

MRI for Cushing Disease: A Systematic Review

BACKGROUND

MR imaging is key in the diagnostic work-up of Cushing disease. The sensitivity of MR imaging in Cushing disease is not known nor is the prognostic significance of "MR imaging-negative" disease.

PURPOSE

Our aim was to determine the overall sensitivity and prognostic significance of MR imaging localization of Cushing disease.

DATA SOURCES

We performed a systematic review of the MEDLINE and PubMed databases for cohort studies reporting the sensitivity of MR imaging for the detection of adenomas in Cushing disease.

STUDY SELECTION

This study included 57 studies, comprising 5651 patients.

DATA ANALYSIS

Risk of bias was assessed using the methodological index for non-randomized studies criteria. Meta-analysis of proportions and pooled subgroup analysis were performed.

DATA SYNTHESIS

Overall sensitivity was 73.4% (95% CI, 68.8%-77.7%), and the sensitivity for microadenomas was 70.6% (66.2%-74.6%). There was a trend toward greater sensitivity in more recent studies and with the use of higher-field-strength scanners. Thinner-section acquisitions and gadolinium-enhanced imaging, particularly dynamic sequences, also increased the sensitivity. The use of FLAIR and newer 3D spoiled gradient-echo and FSE sequences, such as spoiled gradient-echo sequences and sampling perfection with application-optimized contrasts by using different flip angle evolutions, may further increase the sensitivity but appear complementary to standard 2D spin-echo sequences. MR imaging detection conferred a 2.63-fold (95% CI, 2.06-3.35-fold) increase in remission for microadenomas compared with MR imaging-negative Cushing disease.

LIMITATIONS

Pooled analysis is limited by heterogeneity among studies. We could not account for variation in image interpretation and tumor characteristics.

CONCLUSIONS

Detection on MR imaging improves the chances of curative resection of adenomas in Cushing disease. The evolution of MR imaging technology has improved the sensitivity for adenoma detection. Given the prognostic importance of MR imaging localization, further effort should be made to improve MR imaging protocols for Cushing disease.

Ectopic sphenoidal ACTH-secreting adenoma revealed by 11C Methionine PET scan: case report

BACKGROUND

Ectopic ACTH pituitary adenomas (EAPA), located outside the sella turcica and deriving from cellular remnants of Rathke's pouch are a very rare cause of Cushing's syndrome (CS). The diagnosis is often difficult and delayed, even after comprehensive work-up. To our knowledge, we report for the first time an ectopic corticotroph tumor of the posterior wall of the sphenoid sinus, leading to false positive results of bilateral inferior petrosal sinus sampling (BIPPS) and which was finally localized by a co-registered¹¹ C Methionine PET/MR imaging.

CASE PRESENTATION

A 48-year-old woman was referred for a high clinical suspicion of ACTH-dependent CS. Biological testing comprising low dose dexamethasone suppression and CRH stimulation tests were indicative of pituitary Cushing's disease, but comprehensive pituitary MRI did not reveal any pituitary adenoma. BIPSS confirmed however a central origin of ACTH secretion (central-to-peripheral ACTH ratio > 100) and revealed a significant right-to-left gradient (6.2), leading to a first right-sided exploratory hypophysectomy, that did not cure the patient. BIPSS images were reviewed and revealed preferential drainage of the left pituitary to the right petrosal sinus, leading us to a left sided exploratory hypophysectomy, which was again unsuccessful. A¹¹ C Methionine PET/MRI was performed and revealed a hypermetabolic lesion adjacent to the posterior wall of the sphenoidal sinus. After surgical resection, this polypoid mass was identified as an ectopic ATCH-secreting pituitary adenoma expressing ACTH and T-Pit and complete remission of hypercortisolism was observed.

CONCLUSIONS

In conclusion, we report a case of ACTH-dependent Cushing's syndrome, caused by an ectopic corticotroph adenoma located in the sphenoidal sinus, which perfectly mimicked the biological features of a classical pituitary ACTH adenoma on a comprehensive hormonal evaluation including BIPPS, and the features of a benign naso-sinusal polyp at MRI. We report for the first time a key role of¹¹ C Methionine PET co-registered to high resolution MRI for localizing ectopic adenomas, efficiently guiding surgical removal and leading to complete remission of hypercortisolism.

Cortisol and ACTH Measurements at Extubation From Pituitary Surgery Predicts Hypothalamic-Pituitary-Adrenal Axis Function

Context

Early prediction of hypothalamic-pituitary-adrenal (HPA) axis function following transsphenoidal surgery (TSS) can improve patient safety and reduce costs.

Objective

Systematic measurement of ACTH and cortisol at extubation following anesthesia to predict remission from Cushing's disease (CD) and HPA axis preservation following non-CD surgery.

Design

Retrospective analysis of clinical data between August 2015 and May 2022.

Setting

Referral center.

Patients

Consecutive patients (n = 129) undergoing TSS who had perioperative ACTH and cortisol measurements.

Interventions

ACTH and cortisol measurement at extubation. Further serial 6-hourly measurements in CD patients.

Main outcome measures

Prediction of future HPA axis status based on ACTH/cortisol at extubation.

Results

ACTH and cortisol increased sharply in all patients at extubation. CD patients (n = 101) had lower ACTH values than non-CD patients (110.1 vs 293.1 pg/mL; P < 0.01). In non-CD patients, lower plasma ACTH at extubation predicted the need for eventual corticosteroid replacement (105.8 vs 449.1 pg/mL, P < 0.01). In CD patients, the peak post-extubation cortisol at 6 hours was a robust predictor for nonremission (60.7 vs 219.2 µg/dL, P = 0.03). However, normalized early postoperative value (NEPV; the post-extubation values minus the peak preoperative CRH or desmopressin test values) of cortisol reliably distinguished nonremission earlier, at the time of extubation (-6.1 vs 5.9, P = 0.01), and later.

Conclusions

We found that at extubation following TSS, ACTH can predict the need for eventual steroid replacement in non-Cushing's patients. In patients with CD, we found a robust prediction of nonremission with NEPV cortisol at extubation and later.

Gamma Knife Radiosurgery for Cushing's Disease: Evaluation of Biological Effective Dose from a Single-Center Experience

Objective: Gamma knife radiosurgery (GKRS) has served as an adjunctive treatment in Cushing's disease (CD) for decades and has become a vital part of therapy in the management of CD. Biological effective dose (BED) is a radiobiological parameter with time correction, considering the cellular deoxyribonucleic acid repairment. We aimed to investigate the safety and efficacy of GKRS for CD and evaluate the association of BED and treatment outcome. Methods: A cohort study of 31 patients with CD received GKRS in West China Hospital between June 2010 and December 2021. Endocrine remission was defined as normalization of 24 h urinary free cortisol (UFC) or serum cortisol ≤ 50 nmol/L after a 1 mg dexamethasone suppression test. Result: The mean age was 38.6 years old, and females accounted for 77.4%. GKRS was the initial treatment for 21 patients (67.7%), and 32.3% of patients underwent GKRS after surgery due to residual disease and recurrence. The mean endocrine follow-up duration was 22 months. The median marginal dose was 28.0 Gy, and the median BED was 221.5 Gy_2.47. Fourteen patients (45.1%) experienced control of hypercortisolism in the absence of pharmacological treatment, and the median duration to remission was 20.0 months. The cumulative rates of endocrine remission at 1, 2, and 3 years after GKRS were 18.9%, 55.3%, and 72.21%, respectively. The total complication rate was 25.8%, and the mean duration from GKRS to hypopituitary was 17.5 months. The new hypopituitary rate at 1, 2, and 3 years were 7.1%, 30.3%, and 48.4%, respectively. A high BED level (BED > 205 Gy_2.47) was associated with better endocrine remission than a low BED level (BED ≤ 205 Gy_2.47), while no significant differences were found between the BED level and hypopituitarism. Conclusions: GKRS was a second-line therapeutic option for CD with satisfactory safety and efficacy. BED should be considered during GKRS treatment planning, and optimization of BED is a potentially impactful avenue toward improving the efficacy of GKRS.

Overnight Corticosterone and Gene Expression in Mouse Hippocampus: Time Course during Resting Period

The aim of the experiment was to test the effect of an elevated level of glucocorticoids on the mouse hippocampal transcriptome after 12 h of treatment with corticosterone that was administered during an active phase of the circadian cycle. Additionally, we also tested the circadian changes in gene expression and the decay time of transcriptomic response to corticosterone. Gene expression was analyzed using microarrays. Obtained results show that transcriptomic responses to glucocorticoids are heterogeneous in terms of the decay time with some genes displaying persistent changes in expression during 9 h of rest. We have also found a considerable overlap between genes regulated by corticosterone and genes implicated previously in stress response. The examples of such genes are Acer2, Agt, Apod, Aqp4, Etnppl, Fabp7, Fam107a, Fjx1, Fmo2, Galnt15, Gjc2, Heph, Hes5, Htra1, Jdp2, Kif5a, Lfng, Lrg1, Mgp, Mt1, Pglyrp1, Pla2g3, Plin4, Pllp, Ptgds, Ptn, Slc2a1, Slco1c1, Sult1a1, Thbd and Txnip. This indicates that the applied model is a useful tool for the investigation of mechanisms underlying the stress response.

Patient reported outcomes and treatment satisfaction in patients with cushing syndrome

PURPOSE

Cushing Syndrome (CS) is a rare endocrine disorder associated with physical and mental symptoms that can drastically affect quality of life (QoL). This study characterizes QoL in patients with CS, describes their treatment experiences, and identifies patient subsets associated with decreased QoL or shared impressions of treatment.

METHODS

A 136-question survey addressing QoL factors and treatment experiences was completed by adult patients with CS from the Cushing Support and Research Foundation. Patient demographics, tumor characteristics, and treatment information were collected. Bivariate analyses were conducted to determine if patients' symptoms or treatment experiences were significantly associated with demographics or other variables.

RESULTS

A total of 178 patients, predominantly female (94%) with mean age 53 years, completed the survey. Anxiety and/or depression (n = 163, 94%), loss of physical strength (n = 164, 93%), loneliness (n = 156, 90%), fatigue from treatment (n = 142, 89%), memory loss (n = 153, 88%), insomnia (n = 144, 83%), and pain (n = 141, 83%) were symptoms most commonly experienced by respondents. Patients experiencing delay of diagnosis >10 years were more likely to have suicidal thoughts (p = 0.002). Younger patients were more likely to express concerns about hair loss (p = 0.007), loneliness (p = 0.025), pain (p = 0.004), or the impact of CS on their marriage (p = 0.039) or children (p = 0.024).

CONCLUSION

This survey demonstrates CS impacts patients across many dimensions, emphasizing the need for holistic support. We identified patient subsets in which QoL may be improved with additional patient resources or provider attention.

Identification of a novel specific small-molecule melanocortin-2-receptor antagonist

The overproduction of adrenocorticotropic hormone (ACTH), in conditions such as Cushing's disease and congenital adrenal hyperplasia (CAH), leads to significant morbidity. Current treatment with glucocorticoids does not adequately suppress plasma ACTH, resulting in excess adrenal androgen production. At present, there is no effective medical treatment in clinical use that would directly block the action of ACTH. Such a therapy would be of great clinical value. ACTH acts via a highly selective receptor, the melanocortin-2 receptor (MC2R) associated with its accessory protein MRAP. ACTH is the only known naturally occurring agonist for this receptor. This lack of redundancy and the high degree of ligand specificity suggest that antagonism of this receptor could provide a useful therapeutic strategy in the treatment of conditions of ACTH excess. To this end, we screened an extensive library of low-molecular-weight drug-like compounds for MC2R antagonist activity using a high-throughput homogeneous time-resolved fluorescence cAMP assay in Chinese hamster ovary cells stably co-expressing human MC2R and MRAP. Hits that demonstrated MC2R antagonist properties were counter-screened against the β2 adrenergic receptor and dose-response analysis undertaken. This led to the identification of a highly specific MC2R antagonist capable of antagonising ACTH-induced progesterone release in murine Y-1 adrenal cells and having selectivity for MC2R amongst the human melanocortin receptors. This work provides a foundation for the clinical investigation of small-molecule ACTH antagonists as therapeutic agents and proof of concept for the screening and discovery of such compounds.

Approach to the Patient: Diagnosis of Cushing Syndrome

Cushing syndrome results from supraphysiological exposure to glucocorticoids and is associated with significant morbidity and mortality. The pathogenesis includes administration of corticosteroids (exogenous Cushing syndrome) or autonomous cortisol overproduction, whether or not ACTH-dependent (endogenous Cushing syndrome). An early diagnosis of Cushing syndrome is warranted; however, in clinical practice, it is very challenging partly because of resemblance with other common conditions (ie, pseudo-Cushing syndrome). Initial workup should start with excluding local and systemic corticosteroid use. First-line screening tests including the 1-mg dexamethasone suppression test, 24-hour urinary free cortisol excretion, and late-night salivary cortisol measurement should be performed to screen for endogenous Cushing syndrome. Scalp-hair cortisol/cortisone analysis helps in the assessment of long-term glucocorticoid exposure as well as in detection of transient periods of hypercortisolism as observed in cyclical Cushing syndrome. Interpretation of results can be difficult because of individual patient characteristics and hence requires awareness of test limitations. Once endogenous Cushing syndrome is established, measurement of plasma ACTH concentrations differentiates between ACTH-dependent (80%-85%) or ACTH-independent (15%-20%) causes. Further assessment with different imaging modalities and dynamic biochemical testing including bilateral inferior petrosal sinus sampling helps further pinpoint the cause of Cushing's syndrome. In this issue of "Approach to the patient," the diagnostic workup of Cushing syndrome is discussed with answering the questions when to screen, how to screen, and how to differentiate the different causes. In this respect, the latest developments in biochemical and imaging techniques are discussed as well.

Pituitary Adenomas: Classification, Clinical Evaluation and Management

Pituitary adenomas are one of the most common brain tumors. They represent approximately 18% of all intracranial, and around 95% of sellar neoplasms. In recent years, our understanding of the pathophysiology and the behavior of these lesions has led to better control and higher curative rates. The treatment decision is largely dependent on type of the adenoma, clinical presentation, and the size of the lesion. In addition, incidental pituitary lesions add uncertainty in the decision-making process, especially for pituitary adenomas that can be medically managed. When surgery is indicated, the endoscopic endonasal transsphenoidal approach is the technique of choice, but open standard craniotomy approaches can also be the option in selected cases. The following chapter will review the classification, clinical presentation, pathophysiology, diagnostic work-up, selection of surgical approach, and treatment complications in pituitary adenomas.

Pituitary surgery in Cushing's disease: first line treatment and role of reoperation

Cushing's disease is the most common cause of endogenous hypercortisolemia, and transsphenoidal surgery remains the first line therapy for removal of the ACTH-secreting adenoma. While post-operative remission rates are high in experienced hands, there remains a 2% risk of recurrence per year. Patients with the highest chance for cure are those with small, non-invasive tumors that are visible on pre-operative MRI and identified during surgery and are performed by high-volume pituitary neurosurgeons. Surgery for persistent or recurrent disease is frequently indicated and is most successful in the hands of experienced surgeons and in cases where tumor is visible on MRI.

Predictive Value of Early Postoperative Course of Serum Cortisol After Transsphenoidal Surgery for Cushing’s Disease

Objective To identify early available predictors for the long-term outcome of patients after transsphenoidal surgery (TSS) in the management of Cushing’s disease.

Methods This single-center, retrospective study included 93 consecutive patients with Cushing’s disease (follow-up 12–129 months, mean 48, median 38) who underwent TSS (21 had previous operations elsewhere). Six cases had early re-operation, and the resulting data were evaluated instead of the respective first operation. During the postoperative course, serum cortisol levels were assessed every four hours at least until the next morning. An association of parameters with long-term outcomes was tested using binary logistic regression. Receiver operating characteristic curves were used to determine sensitivity, specificity, positive predictive value, and negative predictive value of different cut-off values of serum cortisol in the postoperative course in the event of recurrence after remission.

Results Eighty out of 93 patients (86%) showed postoperative remission (after primary treatment, 60 out of 72 patients, 90.3%). Of these, 8 patients (10%) developed recurrence of hypercortisolism. Compared to patients with persisting long-term remission, those with recurrence differed in cortisol levels starting from 4 pm on the day of surgery plus an event of increasing cortisol during the early postoperative course (“peak”). Binary logistic regression showed the association between a peak of serum cortisol in the early postoperative course with an increased probability of recurrence.

Conclusions Patients with a peak of serum cortisol in the early postoperative course show an increased recurrence rate. A cut-off value of serum cortisol for clear identification of patients with later recurrence could not be determined.

Pituitary adenomas evade apoptosis via noxa deregulation in Cushing's disease

Sporadic pituitary adenomas occur in over 10% of the population. Hormone-secreting adenomas, including those causing Cushing’s disease (CD), cause severe morbidity and early mortality. Mechanistic studies of CD are hindered by a lack of in vitro models and control normal human pituitary glands. Here, we surgically annotate adenomas and adjacent normal glands in 25 of 34 patients. Using single-cell RNA sequencing (RNA-seq) analysis of 27594 cells, we identify CD adenoma transcriptomic signatures compared with adjacent normal cells, with validation by bulk RNA-seq, DNA methylation, qRT-PCR, and immunohistochemistry. CD adenoma cells include a subpopulation of proliferating, terminally differentiated corticotrophs. In CD adenomas, we find recurrent promoter hypomethylation and transcriptional upregulation of PMAIP1 (encoding pro-apoptotic BH3-only bcl-2 protein noxa) but paradoxical noxa downregulation. Using primary CD adenoma cell cultures and a corticotroph-enriched mouse cell line, we find that selective proteasomal inhibition with bortezomib stabilizes noxa and induces apoptosis, indicating its utility as an anti-tumor agent.

Asuzu et al. perform single-cell transcriptomic profiling in Cushing’s disease (CD) adenomas and find overexpression and DNA hypomethylation of PMAIP1, which encodes the pro-apoptotic protein noxa. Noxa is degraded by the proteasome. Proteasomal inhibition rescues noxa and induces apoptosis in CD.

Metabolomics Profiling of Pituitary Adenomas by Raman Spectroscopy, Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy, and Mass Spectrometry of Serum Samples

To date, no studies are available in which pituitary adenomas (PAs) have been studied using techniques like confocal Raman spectroscopy, attenuated total reflection-Fourier transform infrared (FT-IR), and liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the same serum samples. To understand the metabolomics fingerprint, Raman spectra of 16 acromegaly, 19 Cushing's, and 33 nonfunctional PA (NFPA) and ATR-FTIR spectral acquisition of 16 acromegaly, 18 Cushing's, and 22 NFPA patient's serum samples were acquired. Next, Principal component-based linear discriminant analysis (PC-LDA) models were developed, Raman spectral analysis classified acromegaly with an accuracy of 79.17%, sensitivity of 75%, and specificity of 81.25%, Cushing's with an accuracy of 66.67%, sensitivity of 100%, and specificity of 52.63%, and NFPA with an accuracy of 73.17%, sensitivity of 75%, and specificity of 72.73%. ATR-FTIR spectral analysis classified acromegaly with an accuracy of 95.83%, sensitivity of 100%, and specificity of 93.75%, Cushing's with an accuracy of 65.38%, sensitivity of 87.5%, and specificity of 55.56%, and NFPA with an accuracy of 70%, sensitivity of 87.5%, and specificity of 43.75%. In either of the cases, healthy individual cohorts were clearly segregated from the disease cohort, which identified differential regulated regions of nucleic acids, lipids, amides, phosphates, and polysaccharide/C-C residue α helix regions. Furthermore, LC-MS/MS-based analysis of sera samples resulted in the identification of various sphingosine, lipids, acylcarnitines, amino acids, ethanolamine, choline, and their derivatives that differentially regulated in each tumor cohort. We believe cues obtained from the study may be used to generate the metabolite-based test to diagnose PAs from serum in addition to conventional techniques and also to understand disease biology for better disease management, point of care, and improving quality of life in PA patients.

Usefulness of 68 Ga-Pentixafor PET/CT on Diagnosis and Management of Cushing Syndrome

PURPOSE

This pilot study investigated the performance of C-X-C motif chemokine receptor 4 (CXCR4) molecular imaging ( 68 Ga-pentixafor PET/CT) in Cushing syndrome (CS) and the correlation between CXCR4 signaling interactions and glucose metabolism in adrenocorticotropin-cortisol pathway.

METHODS

We retrospectively evaluated 31 patients (16 patients with CS and 15 patients with nonfunctioning pituitary or adrenal adenomas). All patients underwent 68 Ga-pentixafor PET/CT, and 11 with pituitary adenoma also underwent 18 F-FDG PET/CT. The diagnosis accuracy of 68 Ga-pentixafor PET/CT was calculated. The correlation between radiouptake along the pituitary-adrenal axis and hormone levels was calculated.

RESULTS

Patients with Cushing disease characterized a focal uptake in adrenocorticotropic hormone-producing pituitary adenoma (ACTH-PA). In ACTH-independent CS, there was increased uptake of 68 Ga-pentixafor in adrenal lesions but not in the pituitary fossa. The nonfunctioning pituitary or adrenal adenomas showed negative 68 Ga-pentixafor signal. The one patient with metastatic ectopic ACTH syndrome had multiple 68 Ga-pentixafor-avid lesions. Using the threshold of SUV max >8.5 in the adrenal lesions, the sensitivity and specificity of 68 Ga-pentixafor PET/CT to diagnose cortisol-producing adenoma were 100% and 84.9%. A cutoff SUV max value of 3.0 on 68 Ga-pentixafor PET/CT had 100% sensitivity and specificity for differentiating ACTH-PA. The corresponding hormone level was significantly correlated with uptake of 68 Ga-pentixafor in pituitary adenoma and adrenal tissue but not with glucose metabolism.

CONCLUSION

We have characterized the performance of 68 Ga-pentixafor in different subtypes of CS. 68 Ga-pentixafor PET/CT is promising in the differential diagnosis of both ACTH-independent and ACTH-dependent CS. Activated CXCR4 molecular signaling along the pituitary-adrenal axis was found in patients with Cushing disease.

Diagnostic workup of Cushing's syndrome

Cushing's syndrome (CS) is a rare but detrimental endocrine disorder. Early diagnosis and prompt treatment are essential since the duration of hypercortisolism has an adverse impact on the extent of comorbidities and overall survival. The diagnostic approach involves a stepwise process that includes (1) screening and confirming the diagnosis and (2) establishing the aetiology of CS. The tests currently used to confirm the diagnosis of CS include urinary free cortisol measurements, the dexamethasone suppression test and late- night salivary cortisol or midnight serum cortisol measurements. None of these tests are ideal; all have pitfalls and require careful interpretation. Following confirmation of CS, measurement of ACTH discriminates between ACTH-dependent and non-ACTH dependent causes of CS. Adrenal imaging provides clues for the aetiology of non-ACTH dependent forms. Differentiation between the ACTH-dependent forms that involve pituitary corticotroph adenomas and ectopic ACTH sources is more complex and include pituitary MRI imaging, the high dose dexamethasone suppression test, the CRH test, bilateral inferior petrosal sinus sampling and, when required imaging modalities to detect ectopic ACTH secreting lesions. This review, which is part of a special issue on "Update of Cushing's syndrome: 100 years after Minnie G" will provide an update on our current diagnostic workup for the confirmation and differential diagnosis of CS.

Transcription Factor ASCL1 Acts as a Novel Potential Therapeutic Target for the Treatment of the Cushing's Disease

BACKGROUND

The pathogenesis of Cushing's disease (CD) is still not adequately understood despite the identification of somatic driver mutations in USP8, BRAF, and USP48. In this multiomics study, we combined RNA sequencing (RNA-seq) with Sanger sequencing to depict transcriptional dysregulation under different gene mutation backgrounds. Furthermore, we evaluated the potential of achaete-scute complex homolog 1 (ASCL1), a pioneer transcription factor, as a novel therapeutic target for treatment of CD and its possible downstream pathway.

METHODS

RNA-seq was adopted to investigate the gene expression profile of CD, and Sanger sequencing was adopted to detect gene mutations. Bioinformatics analysis was used to depict transcriptional dysregulation under different gene mutation backgrounds. The function of ASCL1 in hormone secretion, cell proliferation, and apoptosis were studied in vitro. The effectiveness of an ASCL1 inhibitor was evaluated in primary CD cells, and the clinical relevance of ASCL1 was examined in 68 patients with CD. RNA-seq in AtT-20 cells on Ascl1 knockdown combined with published chromatin immunoprecipitation sequencing data and dual luciferase assays were used to explore downstream pathways.

RESULTS

ASCL1 was exclusively overexpressed in USP8-mutant and wild-type tumors. Ascl1 promoted adrenocorticotrophin hormone overproduction and tumorigenesis and directly regulated Pomc in AtT-20 cells. An ASCL1 inhibitor presented promising efficacy in both AtT-20 and primary CD cells. ASCL1 overexpression was associated with a larger tumor volume and higher adrenocorticotrophin secretion in patients with CD.

CONCLUSION

Our findings help to clarify the pathogenesis of CD and suggest that ASCL1 is a potential therapeutic target the treatment of CD.

SUMMARY

The pathogenesis of Cushing's disease (CD) is still not adequately understood despite the identification of somatic driver mutations in USP8, BRAF, and USP48. Moreover, few effective medical therapies are currently available for the treatment of CD. Here, using a multiomics approach, we first report the aberrant overexpression of the transcription factor gene ASCL1 in USP8-mutant and wild-type tumors of CD. Ascl1 promoted adrenocorticotrophin hormone overproduction and tumorigenesis and directly regulated Pomc in mouse AtT-20 cells. Notably, an ASCL1 inhibitor presented promising efficacy in both AtT-20 and primary CD cells. Importantly, ASCL1 overexpression was associated with a larger tumor volume and higher adrenocorticotrophin secretion in patients with CD. Thus, our findings improve understanding of CD pathogenesis and suggest that ASCL1 is a potential therapeutic target the treatment of CD.

Recent advancements in the molecular biology of pituitary adenomas

INTRODUCTION

Pituitary adenomas are a common and diverse group of intracranial tumors arising from the anterior pituitary that are usually slow-growing and benign, but still pose a significant healthcare burden to patients. Additionally, they are increasing in both incidence and prevalence, leading to a need for better understanding of molecular changes in the development of these tumors.

AREAS COVERED

A PubMed literature search was conducted using the terms 'pituitary adenoma' in combination with keywords related to secretory subtype: lactotroph, somatotroph, corticotroph, gonadotroph and null cell, in addition to their transcription factor expression: PIT1, TPIT, and SF-1. Articles resulting from this search were analyzed, as well as relevant articles cited as their references. In this review, we highlight recent advances in the genetic and epigenetic characterization of individual pituitary adenoma subtypes and the effect it may have on guiding future clinical treatment of these tumors.

EXPERT OPINION

Understanding the molecular biology of pituitary adenomas is a fundamental step toward advancing the treatment of these tumors. Yet crucial knowledge gaps exist in our understanding of the underlying molecular biology of pituitary adenomas which can potentially be addressed by turning to differentially activated molecular pathways in tumor relative to normal gland.

MRI-negative Cushing's Disease: Management Strategy and Outcomes in 15 Cases Utilizing a Pure Endoscopic Endonasal Approach

BACKGROUND

Cushing's disease (CD) is among the most common etiologies of hypercortisolism. Magnetic resonance imaging (MRI) is often utilized in the diagnosis of CD, however, up to 64% of adrenocorticotropic hormone (ACTH)-producing pituitary microadenomas are undetectable on MRI. We report 15 cases of MRI negative CD who underwent surgical resection utilizing a purely endoscopic endonasal approach.

METHODS

Endoscopic endonasal transsphenoidal surgery (EETS) was performed on 134 CD cases by a single surgeon. Fifteen cases met inclusion criteria: no conclusive MRI studies and no previous surgical treatment. Data collected included signs/symptoms, pre- and post-operative hormone levels, and complications resulting from surgical or medical management. Data regarding tumor diameter, location, and tumor residue/recurrence was obtained from both pre- and post-operative MRI. Immunohistochemistry was performed to assess for tumor hormone secretion.

RESULTS

Aside from a statistically significant difference (P = 0.001) in histopathological results between patients with negative and positive MRI, there were no statistically significant difference between these two groups in any other demographic or clinical data point. Inferior petrosal sinus sampling (IPSS) with desmopressin (DDAVP®) administration was performed on the 15 patients with inconclusive MRIs to identify the origin of ACTH hypersecretion via a central/peripheral (C/P) ratio. IPSS in seven, five and three patients showed right, left, and central side lateralization, respectively. With a mean follow-up of 5.5 years, among MRI-negative patients, 14 (93%) and 12 patients (80%) achieved early and long-term remission, respectively. In the MRI-positive cohort, over a mean follow-up of 4.8 years, 113 patients (94.9%) and 102 patients (85.7%) achieved initial and long-term remission, respectively.

CONCLUSIONS

Surgical management of MRI-negative/inconclusive Cushing's disease is challenging scenario requiring a multidisciplinary approach. An experienced neurosurgeon, in collaboration with a dedicated endocrinologist, should identify the most likely location of the adenoma utilizing IPSS findings, followed by careful surgical exploration of the pituitary to identify the adenoma.

Ultra-high field 7 T MRI localizes regional brain volume recovery following corticotroph adenoma resection and hormonal remission in Cushing's disease: A case series

Background

Cushing's disease (CD) is defined by glucocorticoid excess secondary to the increased section of corticotropin by a pituitary adenoma. Magnetic resonance imaging (MRI) studies performed at 1.5 or 3 Tesla (T) have demonstrated correlations between regional changes in brain structure and the progression of CD. In this report, we examine the changes in brain volume following corticotroph pituitary adenoma resection using ultra-high field 7 T MRI to increase the accuracy of our volumetric analyses.

Methods

Thirteen patients were referred to the endocrinology clinic at our institution from 2017 to 2020 with symptoms of cortisol excess and were diagnosed with ACTH-dependent endogenous Cushing syndrome. Five patients had follow-up 7 T imaging at varying time points after a transsphenoidal resection.

Results

Symmetrized percent change in regional volumes demonstrated a postoperative increase in cortical volume that was relatively larger than that of cerebral white matter or subcortical gray matter (percent changes = 0.0172%, 0.0052%, and 0.0120%, respectively). In the left cerebral hemisphere, the medial orbitofrontal, lateral orbitofrontal, and pars opercularis cortical regions experienced the most robust postoperative percent increases (percent changes = 0.0166%, 0.0122%, and 0.0068%, respectively). In the right cerebral hemisphere, the largest percent increases were observed in the pars triangularis, rostral portion of the middle frontal gyrus, and superior frontal gyrus (percent changes = 0.0156%, 0.0120%, and 0.0158%).

Conclusion

Cerebral volume recovery following pituitary adenoma resection is driven by changes in cortical thickness predominantly in the frontal lobe, while subcortical white and gray matter volumes increase more modestly.

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.

Celastrol Induces Apoptosis and Autophagy via the AKT/mTOR Signaling Pathway in the Pituitary ACTH-secreting Adenoma Cells

OBJECTIVE

Pituitary adrenocorticotropic hormone (ACTH)-secreting adenoma is a relatively intractable endocrine adenoma that can cause a range of severe metabolic disorders and pathological changes involving multiple systems. Previous studies have shown that celastrol has antitumor effects on a variety of tumor cells via the AKT/mTOR signaling. However, whether celastrol has pronounced antitumor effects on pituitary ACTH-secreting adenoma is unclear. This study aimed to identify a new effective therapeutic drug for pituitary ACTH-secreting adenoma.

METHODS

Mouse pituitary ACTH-secreting adenoma cells (AtT20 cells) were used as an experimental model in vitro and to establish a xenograft tumor model in mice. Cells and animals were administered doses of celastrol at various levels. The effects of celastrol on cell viability, migration, apoptosis and autophagy were then examined. Finally, the potential involvement of AKT/mTOR signaling in celastrol's mechanism was assessed.

RESULTS

Celastrol inhibited the proliferation and migration of pituitary adenoma cells in a time- and concentration-dependent manner. It blocked AtT20 cells in the G0/G1 phase, and induced apoptosis and autophagy by downregulating the AKT/mTOR signaling pathway. Similar results were obtained in mice.

CONCLUSION

Celastrol exerts potent antitumor effects on ACTH-secreting adenoma by downregulating the AKT/mTOR signaling in vitro and in vivo.

Characterization of a paradoxical post-operative increase in serum cortisol in Cushing disease

PURPOSE

In Cushing disease, early post-operative serum cortisol fluctuations have not been adequately characterized, and their association with initial remission and recurrence is unclear.

METHODS

A retrospective cohort study of patients with Cushing disease was conducted at two institutions. A "riser" was defined a priori as a paradoxical increase in serum cortisol with an immediate incremental increase in serum cortisol over three consecutive cortisol draws separated by roughly 6-h (definition 1). Post hoc analyses used a definition of two consecutive increases (definition 2). Risers were compared to non-risers for initial remission and time-to-recurrence.

RESULTS

A total of 505 patients with Cushing disease were screened, and 469 had adequate data for group assignment. Analysis of post-operative cortisol showed a subgroup of "risers" with a frequency of 3.6% for definition 1 and 42.6% for definition 2. In these patients, cortisol levels were significantly higher until approximately 36 h post-operatively, and cortisol had a significantly longer mean serum half-life. In the post hoc analysis, definition 2 risers had a lower remission rate compared to non-risers (162/196, 82.7%, versus 243/264, 92.0%) with an odds ratio of 0.41 (0.23-0.73; p = 0.003). For both definitions, recurrence was similar between groups.

CONCLUSIONS

We found that almost half of Cushing disease patients experienced a temporary increase in serum cortisol level during the early post-operative period. Serum cortisol half-life was longer, and the remission rates were lower, however, recurrence rates were similar to non-risers.

Ultra-High-Field 7 T Magnetic Resonance Imaging Including Dynamic and Static Contrast-Enhanced T1-Weighted Imaging Improves Detection of Secreting Pituitary Microadenomas

OBJECTIVE

A prospective preoperative evaluation of 7 T ultra-high-field magnetic resonance imaging (MRI) in patients with suspected pituitary microadenomas for both adenoma detection and intrasellar localization compared with 3 T MRI was carried out.

MATERIALS AND METHODS

Patients underwent prospective preoperative standardized 3 and 7 T MRI. A distinct qualitative (lesion detection, intrasellar lesion location) and quantitative (lesion diameters, T1/T2 signal intensity ratio of the lesion to normal pituitary gland tissue) analysis was performed, along with an evaluation of image quality (IQ) regarding overall IQ, anatomical parameters, and artifacts; the findings of the qualitative analysis were compared with intraoperative findings and endocrinological outcomes.

RESULTS

Sixteen patients (mean age, 43 ± 16 years; 13 women) with pituitary microadenomas were included. Using 7 T MRI allowed the detection of 15 microadenomas-3 more than 3 T MRI. In addition, 7 T MRI allowed more precise lesion localization with 93.75% (15/16) agreement with intraoperative findings, compared with 75% (12/16) agreement using 3 T MRI. Lesion diameters showed no significant difference between 3 and 7 T MRI. T1 and T2 signal intensity ratio between microadenomas and normal pituitary gland tissue were higher in 7 T MRI than in 3 T MRI. The overall IQ and the IQ of each anatomical parameter of 7 T MRI were rated higher than those of 3 T MRI. No significant differences in susceptibility or head motion artifacts were observed between 3 and 7 T MRI; however, 7 T MRI was more susceptible to pulsation artifacts.

CONCLUSION

Ultra-high-field MRI surpasses 3 T MRI in pituitary microadenoma detection and enables more precise delineation with higher correlation with intraoperative findings. Thus, 7 T sellar imaging is a promising option-especially in previously magnetic resonance-negative patients with endocrinologically confirmed hormone oversecretion-and helps reduce the need for invasive diagnostics.

Past, Present, and Future of Therapies for Pituitary Neuroendocrine Tumors: Need for Omics and Drug Repositioning Guidance

Innovation roadmaps are important, because they encourage the actors in an innovation ecosystem to creatively imagine multiple possible science future(s), while anticipating the prospects and challenges on the innovation trajectory. In this overarching context, this expert review highlights the present unmet need for therapeutic innovations for pituitary neuroendocrine tumors (PitNETs), also known as pituitary adenomas. Although there are many drugs used in practice to treat PitNETs, many of these drugs can have negative side effects and show highly variable outcomes in terms of overall recovery. Building innovation roadmaps for PitNETs' treatments can allow incorporation of systems biology approaches to bring about insights at multiple levels of cell biology, from genes to proteins to metabolites. Using the systems biology techniques, it will then be possible to offer potential therapeutic strategies for the convergence of preventive approaches and patient-centered disease treatment. Here, we first provide a comprehensive overview of the molecular subtypes of PitNETs and therapeutics for these tumors from the past to the present. We then discuss examples of clinical trials and drug repositioning studies and how multi-omics studies can help in discovery and rational development of new therapeutics for PitNETs. Finally, this expert review offers new public health and personalized medicine approaches on cases that are refractory to conventional treatment or recur despite currently used surgical and/or drug therapy.

Utility of bilateral inferior petrosal sinus sampling for diagnosis and lateralization of Cushing's disease in the pediatric population: case series and review of the literature

OBJECTS

Cushing's disease (CD) is the most common cause of ACTH-dependent hypercortisolism in children age ≥ 7. The utility of bilateral inferior petrosal sinus sampling (BIPSS), an important test in adults, is less defined in children. We present a case series of children with ACTH-dependent hypercortisolemia and review the literature to assess the utility of BIPSS in the diagnosis and localization of CD.

METHODS

We performed an IRB-approved chart review of patients aged ≤ 18 with ACTH-dependent hypercortisolism at MGH between 2000 and 2019 and collected clinical, laboratory, radiographic, BIPSS, surgical, and outcomes data.

RESULTS

In our cohort (n = 21), BIPSS had a sensitivity of 93% and specificity of 100% for diagnosis of CD. Compared to surgery, successful BIPSS correctly predicted adenoma laterality in 69% of cases vs. 70% by MRI. Among patients with lesions ≥ 4 mm (n = 9), BIPSS correctly lateralized in 50% vs. 100% by MRI. In patients with subtle lesions (< 4 mm, n = 7), BIPSS correctly lateralized in 80% vs. 71% by MRI. In patients (n = 4) with CD and negative MRIs, BIPSS correctly lateralized in 75% cases. Surgical cure was achieved in 90% of patients and 95% of patients had long-term disease control.

CONCLUSIONS

In our cohort (n = 21; n = 20 CD, n = 1 ectopic ACTH secretion), BIPSS was sensitive and specific for the diagnosis of CD. Compared to MRI, BIPSS was not additionally helpful for lateralization in patients with lesions ≥ 4 mm on MRI. BIPSS was helpful in guiding surgical exploration and achieving immediate postoperative remission among patients with subtle and negative MRI findings.

High-dose dexamethasone suppression test is inferior to pituitary dynamic enhanced MRI in the differential diagnosis of ACTH-dependent Cushing's syndrome

PURPOSE

The differential diagnosis of adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome remains a challenge in clinical practice. The present study was aimed at assessing the diagnostic performance of pituitary dynamic contrast-enhanced magnetic resonance imaging (dMRI), high-dose dexamethasone suppression test (HDDST), and a combination of both tests for patients with ACTH-dependent Cushing's syndrome.

METHODS

A total of 119 consecutive patients with ACTH-dependent Cushing's syndrome confirmed surgically were enrolled: 101 with proven Cushing's disease and 18 with proven ectopic ACTH syndrome. All patients underwent pituitary dMRI and HDDST. The sensitivity and specificity of pituitary dMRI, HDDST, and a combination of both tests were determined.

RESULTS

The sensitivity and specificity of pituitary dMRI for diagnosing Cushing's disease were 80.2 and 83.3%, respectively, with a positive predictive value of 96.4%. The sensitivity and specificity of HDDST were 70.3 and 77.8%, respectively, with positive predictive value of 94.7%. A combination of both tests showed that the combined criteria of more than 50% suppression of serum cortisol on HDDST and a positive pituitary dMRI finding yielded a high specificity of 94.4 and sensitivity of 59.4%. The combined criteria of more than 68% suppression on HDDST and/or a positive pituitary dMRI finding yielded a sensitivity of 86.1% and specificity of 83.3%.

CONCLUSIONS

Pituitary dMRI was superior to HDDST in the differential diagnosis of ACTH-dependent Cushing's syndrome. HDDST is recommended in combination with pituitary dMRI to establish a diagnosis process because of the significantly increased specificity with the combination.