Subtyping of Cushing's syndrome: a step ahead.

Cushing's Syndrome (CS) is a rare disease due to chronic endogenous cortisol secretion. In the last years, new acquisitions enlarged the spectrum of differential diagnosis, historically divided into ACTH-dependent and ACTH-independent forms. Moreover, the increased awareness of the detrimental cortisol effects on cardiometabolic health and the risk of cardiovascular events lead to increased diagnosis of mild forms, especially in the context of adrenal incidentalomas. We provide and up-to-date narrative review of the most recent literature regarding the challenges of CS diagnosis. After the description of the diagnostic tools available, we describe the characterization of functional non-neoplastic hypercortisolism (formerly known as pseudo-Cushing state), then we report the subtyping of the different conditions of hypercortisolism: the differential diagnosis of ACTH-dependent forms and the management of adrenal hypercortisolism, with peculiar attention to the new genetic classification of adrenal CS, mild autonomous cortisol secretion and bilateral adrenal adenomas.

A novel somatostatin receptor ligand for human ACTH - and GH -secreting pituitary adenomas.

OBJECTIVE: Somatostatin receptor ligands have come to play a pivotal role in the treatment of both ACTH- and GH-secreting pituitary adenomas. Clinical efficacy averages 30-50%, thus a considerable number of patients with Cushing's disease or acromegaly remain unresponsive to this therapeutic approach. HTL0030310 is a new somatostatin receptor ligand selective for subtype 5 over subtype 2, thus with a different receptor profile compared to clinical somatostatin receptor ligands. DESIGN: Assessment of the effect of HTL0030310 on hormone secretion in human ACTH- and GH-secreting pituitary adenomas in vitro. METHODS: Primary cultures from 3 ACTH-secreting and 5 GH-secreting pituitary adenomas were treated with 1, 10 and 100 nM HTL0030310 alone or with 10 nM CRH or GHRH, respectively. Parallel incubations with 10 nM pasireotide were also carried out. ACTH and GH secretion were assessed after 4 and 24 hour incubation; SSTR2, SSTR3, SSTR5, GH and POMC expression were evaluated after 24 hours. RESULTS: HTL0030310 reduced unchallenged ACTH and POMC levels up to 50% in 2 ACTH-secreting adenomas and blunted CRH-stimulated ACTH/POMC by 20-70% in all 3 specimens. A reduction in spontaneous GH secretion was observed in 4 GH-secreting adenomas and in 2 specimens during GHRH co-incubation. SSTRs expression was detected in all specimens. CONCLUSIONS: This first study on a novel somatostatin receptor 5-preferring ligand indicates that HTL0030310 can inhibit hormonal secretion in human ACTH- and GH-secreting pituitary adenomas. These findings suggest a potential new avenue for somatostatin ligands in the treatment of Cushing's disease and acromegaly.

Knowing when to discontinue Temozolomide therapy in responding aggressive pituitary tumors and carcinomas: a systematic review and Padua (Italy) case series.

INTRODUCTION: Pituitary adenomas can show a tendency to grow, despite multimodal treatment. Temozolomide (TMZ) has been used in the last 15 years in patients with aggressive pituitary tumors. TMZ requires a careful balance of different expertise, especially for selection criteria. AREAS COVERED: We conducted: (1) a systematic review of the published literature from 2006 to 2022, collecting only cases with a complete description of patient follow-up after TMZ discontinuation; (2) a description of all patients with aggressive pituitary adenoma or carcinoma treated in Padua (Italy). EXPERT OPINION: There is considerable heterogeneity in the literature: TMZ cycles duration ranged from 3 to 47 months; the follow-up time after TMZ discontinuation ranged from 4 to 91 months (mean 24 months, median 18 months), at least a stable disease has been reported in 75% of patients after a mean 13 months (range 3-47 months, median 10 months). The Padua (Italy) cohort reflects the literature. Future directions to explore are to understand the pathophysiological mechanism of TMZ resistance escape, to develop predicting factors to TMZ treatment (especially through the delineation of the underlying transformation processes), and to further expand the therapeutic applications of TMZ (as neoadjuvant, combined with radiotherapy).

Dynamic Testing for Differential Diagnosis of ACTH-Dependent Cushing Syndrome: A Systematic Review and Meta-analysis.

CONTEXT: Diagnostic accuracy of testing currently used for the differential diagnosis of Cushing disease (CD) vs ectopic adrenocorticotropic hormone secretion (EAS) is difficult to interpret. OBJECTIVE: The present study aimed to identify and evaluate the diagnostic accuracy of the corticotropin-releasing hormone (CRH) test, the desmopressin test, and the high-dose dexamethasone suppression test (HDDST) when used to establish a CD or EAS diagnosis. METHODS: This study is a systematic review of the literature and meta-analysis. MEDLINE, OVID, and Web of Science databases were searched for articles published between 1990 and 2021. Articles included described at least 1 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 the HDDST; 32, the CRH test; and the 21, the desmopressin test. The CRH test was found to have the highest sensitivity in detecting CD (ACTH 86.9%, 95% 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 of 0.934. The diagnostic accuracy of the HDDST and desmopressin test 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 analyzing role of dynamic testing in addition to imaging are needed.

Long-Lasting Effects of Spironolactone after its Withdrawal in Patients with Hyperandrogenic Skin Disorders.

OBJECTIVE: Hyperandrogenic skin disorders, such as hirsutism, acne and alopecia, affect approximately 10-20% of women of reproductive age, reducing quality of life and causing psychological impairment. Spironolactone is a commonly used antiandrogen, especially in women who are not sexually active or have contraindications to hormonal contraceptives. The aim of this study was to evaluate the effects of spironolactone, especially after its withdrawal, in patients with hyperandrogenic skin disorders. METHODS: Retrospective analysis of 63 women with hyperandrogenic skin symptoms due to polycystic ovary syndrome (PCOS), treated with spironolactone for at least 6 months as first-line treatment. RESULTS: After a mean time of treatment of 25.7 months, all patients reported a significant improvement in hyperandrogenic skin disorders; only 5 patients were dissatisfied and required the addition of an oral contraceptive. The therapy was well tolerated and the most frequent side-effect was intermestrual bleeding in 68.2% of cases, affecting mainly classic PCOS phenotype. Thirthyeight patients showed prolonged effects 33.7 months after spironolactone withdrawal, whereas 20 relapsed 17.5 months after discontinuation. No significant difference in clinical and biochemical parameters was observed between these two groups both at baseline and after spironolactone treatment. Ovulatory PCOS patients were treated for a shorter time and reported earlier relapse than classic PCOS patients. CONCLUSION: Spironolactone is an effective and safe treatment for hyperandrogenic skin disorders, showing long-lasting effects even several months after its discontinuation.

Pasireotide-Induced Shrinkage in GH and ACTH Secreting Pituitary Adenoma: A Systematic Review and Meta-Analysis.

Introduction: Pasireotide (PAS) is a novel somatostatin receptor ligands (SRL), used in controlling hormonal hypersecretion in both acromegaly and Cushing's Disease (CD). In previous studies and meta-analysis, first-generation SRLs were reported to be able to induce significant tumor shrinkage only in somatotroph adenomas. This systematic review and meta-analysis aim to summarize the effect of PAS on the shrinkage of the pituitary adenomas in patients with acromegaly or CD. Materials and methods: We searched the Medline database for original studies in patients with acromegaly or CD receiving PAS as monotherapy, that assessed the proportion of significant tumor shrinkage in their series. After data extraction and analysis, a random-effect model was used to estimate pooled effects. Quality assessment was performed with a modified Joanna Briggs's Institute tool and the risk of publication bias was addressed through Egger's regression and the three-parameter selection model. Results: The electronic search identified 179 and 122 articles respectively for acromegaly and CD. After study selection, six studies considering patients with acromegaly and three with CD fulfilled the eligibility criteria. Overall, 37.7% (95%CI: [18.7%; 61.5%]) of acromegalic patients and 41.2% (95%CI: [22.9%; 62.3%]) of CD patients achieved significant tumor shrinkage. We identified high heterogeneity, especially in acromegaly (I2 of 90% for acromegaly and 47% for CD), according to the low number of studies included. Discussion: PAS treatment is effective in reducing tumor size, especially in acromegalic patients. This result strengthens the role of PAS treatment in pituitary adenomas, particularly in those with an invasive behavior, with progressive growth and/or extrasellar extension, with a low likelihood of surgical gross-total removal, or with large postoperative residual tissue. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022328152, identifier CRD42022328152.

The Role of Glucocorticoid Receptor in the Pathophysiology of Pituitary Corticotroph Adenomas.

Adrenocorticotropic Hormone (ACTH)-secreting pituitary adenomas are rare tumors characterized by autonomous ACTH secretion with a consequent increase in circulating cortisol levels. The resulting clinical picture is called Cushing's disease (CD), a severe condition burdened with high morbidity and mortality. Apart from increased cortisol levels, CD patients exhibit a partial resistance to the negative glucocorticoid (GC) feedback, which is of paramount clinical utility, as the lack of suppression after dexamethasone administration is one of the mainstays for the differential diagnosis of CD. Since the glucocorticoid receptor (GR) is the main regulator of negative feedback of the hypothalamic-pituitary-adrenal axis in normal conditions, its implication in the pathophysiology of ACTH-secreting pituitary tumors is highly plausible. In this paper, we review GR function and structure and the mechanisms of GC resistance in ACTH-secreting pituitary tumors and assess the effects of the available medical therapies targeting GR on tumor growth.

Incretin Response to Mixed Meal Challenge in Active Cushing's Disease and after Pasireotide Therapy.

Cushing's disease (CD) causes diabetes mellitus (DM) through different mechanisms in a significant proportion of patients. Glucose metabolism has rarely been assessed with appropriate testing in CD; we aimed to evaluate hormonal response to a mixed meal tolerance test (MMTT) in CD patients and analyzed the effect of pasireotide (PAS) on glucose homeostasis. To assess gastro-entero-pancreatic hormones response in diabetic (DM+) and non-diabetic (DM−) patients, 26 patients with CD underwent an MMTT. Ten patients were submitted to a second MMTT after two months of PAS 600 µg twice daily. The DM+ group had significantly higher BMI, waist circumference, glycemia, HbA1c, ACTH levels and insulin resistance indexes than DM− (p < 0.05). Moreover, DM+ patients exhibited increased C-peptide (p = 0.004) and glucose area under the curve (AUC) (p = 0.021) during MMTT, with a blunted insulinotropic peptide (GIP) response (p = 0.035). Glucagon levels were similar in both groups, showing a quick rise after meals. No difference in estimated insulin secretion and insulin:glucagon ratio was found. After two months, PAS induced an increase in both fasting glycemia and HbA1c compared to baseline (p < 0.05). However, this glucose trend after meal did not worsen despite the blunted insulin and C-peptide response to MMTT. After PAS treatment, patients exhibited reduced insulin secretion (p = 0.005) and resistance (p = 0.007) indexes. Conversely, glucagon did not change with a consequent impairment of insulin:glucagon ratio (p = 0.009). No significant differences were observed in incretins basal and meal-induced levels. Insulin resistance confirmed its pivotal role in glucocorticoid-induced DM. A blunted GIP response to MMTT in the DM+ group might suggest a potential inhibitory role of hypercortisolism on enteropancreatic axis. As expected, PAS reduced insulin secretion but also induced an improvement in insulin sensitivity as a result of cortisol reduction. No differences in incretin response to MMTT were recorded during PAS therapy. The discrepancy between insulin and glucagon trends while on PAS may be an important pathophysiological mechanism in this iatrogenic DM; hence restoring insulin:glucagon ratio by either enhancing insulin secretion or reducing glucagon tone can be a potential therapeutic target.

Loss of KDM1A in GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome: a multicentre, retrospective, cohort study.

BACKGROUND: GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome is caused by aberrant expression of the GIP receptor in adrenal lesions. The bilateral nature of this disease suggests germline genetic predisposition. We aimed to identify the genetic driver event responsible for GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome. METHODS: We conducted a multicentre, retrospective, cohort study at endocrine hospitals and university hospitals in France, Canada, Italy, Greece, Belgium, and the Netherlands. We collected blood and adrenal samples from patients who had undergone unilateral or bilateral adrenalectomy for GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome. Adrenal samples from patients with primary bilateral macronodular adrenal hyperplasia who had undergone an adrenalectomy for overt or mild Cushing's syndrome without evidence of food-dependent cortisol production and those with GIP-dependent unilateral adrenocortical adenomas were used as control groups. We performed whole genome, whole exome, and targeted next generation sequencing, and copy number analyses of blood and adrenal DNA from patients with familial or sporadic disease. We performed RNA sequencing on adrenal samples and functional analyses of the identified genetic defect in the human adrenocortical cell line H295R. FINDINGS: 17 patients with GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome were studied. The median age of patients was 43·3 (95% CI 38·8-47·8) years and most patients (15 [88%]) were women. We identified germline heterozygous pathogenic or most likely pathogenic variants in the KDM1A gene in all 17 patients. We also identified a recurrent deletion in the short p arm of chromosome 1 harboring the KDM1A locus in adrenal lesions of these patients. None of the 29 patients in the control groups had KDM1A germline or somatic alterations. Concomitant genetic inactivation of both KDM1A alleles resulted in loss of KDM1A expression in adrenal lesions. Global gene expression analysis showed GIP receptor upregulation with a log2 fold change of 7·99 (95% CI 7·34-8·66; p=4·4 × 10-125), and differential regulation of several other G protein-coupled receptors in GIP-dependent primary bilateral macronodular hyperplasia samples compared with control samples. In vitro pharmacological inhibition and inactivation of KDM1A by CRISPR-Cas9 genome editing resulted in an increase of GIP receptor transcripts and protein in human adrenocortical H295R cells. INTERPRETATION: We propose that GIP-dependent primary bilateral macronodular adrenal hyperplasia with Cushing's syndrome results from a two-hit inactivation of KDM1A, consistent with the tumour suppressor gene model of tumorigenesis. Genetic testing and counselling should be offered to these patients and their relatives. FUNDING: Agence Nationale de la Recherche, Fondation du Grand défi Pierre Lavoie, and the French National Cancer Institute.

Anastrozole as add-on therapy for cabergoline-resistant prolactin-secreting pituitary adenomas: real-life experience in male patients.

INTRODUCTION: Prolactin-secreting adenoma (PRLoma) can present as large and invasive neoplasm, with increased markers of cellular proliferation. First-line approach is Dopamine Agonists (DAs) treatment; however, DA-resistance has been reported, especially in male patients. Estrogens induce lactotroph cell replication and PRL secretion: the use of anti-estrogen treatment in patients with PRLoma have been described in few cases. We reported our experience regarding treatment with the aromatase inhibitor anastrozole (ANA) as add-on therapy for male patients with DA resistant PRLoma. MATERIALS AND METHODS: We describe four male patients (26, 38, 29 and 19 years old at diagnosis), with PRLoma (median diameter 26 mm, PRL 7730 µg/L). They were resistant to cabergoline (CAB, > 2 mg/week) in terms of PRL secretion and tumor size reduction. ANA 1 mg/day was added to the maximum tolerated dose of CAB for at least 1 year. Magnetic Resonance was performed at baseline, after 6 months of CAB + ANA combination and every 12 months afterward. RESULTS: PRL levels decreased in all patients after CAB + ANA (mean - 70%, range - 44/- 97%), achieving a normalization of PRL levels in one case. Tumor size decreased in all cases (mean - 47%, range - 24.5/- 68%). No severe adverse effects have been reported, a moderate weight gain has been observed in two cases. CONCLUSIONS: Addition of an aromatase inhibitor (ANA) to the dopamine agonist therapy improved the control of prolactin levels and induced tumour regression.

Second-Line Tests in the Diagnosis of Adrenocorticotropic Hormone-Dependent Hypercortisolism.

Cushing's syndrome (CS) is a rare disease caused by chronic and excessive cortisol secretion. When adrenocorticotropin hormone (ACTH) is measurable, autonomous adrenal cortisol secretion could be reasonably ruled out in a differential diagnosis of CS. ACTH-dependent CS accounts for 80%-85% of cases and involves cortisol production stimulated by uncontrolled pituitary or ectopic ACTH secretion. Pituitary adenoma is not detected in up to one-third of cases with pituitary ACTH secretion, whereas cases of CS due to ectopic ACTH secretion may be associated with either malignant neoplasia (such as small cell lung carcinoma) or less aggressive neuroendocrine tumors, exhibiting only the typical symptoms and signs of CS. Since the differential diagnosis of ACTH-dependent CS may be a challenge, many strategies have been proposed. Since none of the available tests show 100% diagnostic accuracy, a step-by-step approach combining several diagnostic tools and a multidisciplinary evaluation in a referral center is suggested. In this review, we present a clinical case to demonstrate the diagnostic work-up of ACTH-dependent CS. We describe the most commonly used dynamic tests, as well as the applications of conventional or nuclear imaging and invasive procedures.

Clinical presentation and management of acromegaly in elderly patients.

BACKGROUND AND AIM: Acromegaly is a rare disease with a peak of incidence in early adulthood. However, enhanced awareness of this disease, combined with wide availability of magnetic resonance imaging (MRI), has increased the diagnosis of forms with mild presentation, especially in elderly patients. Moreover, due to increased life expectancy and proactive individualized treatment, patients with early-onset acromegaly are today aging. The aim of our study was to describe our cohort of elderly patients with acromegaly. MATERIALS AND METHODS: This is a cross-sectional retrospective study of 96 outpatients. Clinical, endocrine, treatment, and follow-up data were collected using the electronic database of the University Hospital of Padova, Italy. RESULTS: We diagnosed acromegaly in 13 patients, aged ≥65 years, presenting with relatively small adenomas and low IGF-1 secretion. Among them, 11 patients were initially treated with medical therapy and half normalized hormonal levels after 6 months without undergoing neurosurgery (TNS). Remission was achieved after TNS in three out of four patients (primary TNS in two); ten patients presented controlled acromegaly at the last visit. Acromegaly-related comorbidities (colon polyps, thyroid cancer, adrenal incidentaloma, hypertension, and bone disease) were more prevalent in patients who had an early diagnosis (31 patients, characterized by a longer follow-up of 24 years) than in those diagnosed aged ≥65 years (5 years of follow-up). CONCLUSIONS: Elderly acromegalic patients are not uncommon. Primary medical therapy is a reasonable option and is effectively used, while the rate of surgical success is not reduced. A careful cost-benefit balance is suggested. Disease-specific comorbidities are more prevalent in acromegalic patients with a longer follow-up rather than in those diagnosed aged ≥65 years.

Pharmacological Approaches to Controlling Cardiometabolic Risk in Women with PCOS.

Polycystic ovary syndrome (PCOS) is characterized by elevated androgen production and subclinical changes in cardiovascular and metabolic risk markers. Total cholesterol, high-density lipoprotein (HDL) cholesterol, fasting glucose, and fasting insulin appear to increase specifically in PCOS compared with fertile women. PCOS also confers an increased risk of cardiometabolic disease in later life. Novel biomarkers such as serum's cholesterol efflux capacity and blood-derived macrophage activation profile may assist in more accurately defining the cardiometabolic risk profile in these women. Aldosterone antagonists, androgen receptor antagonists, 5α-reductase inhibitors, and synthetic progestogens are used to reduce hyperandrogenism. Because increased insulin secretion enhances ovarian androgen production, short-term treatment with metformin and other hypoglycemic agents results in significant weight loss, favorable metabolic changes, and testosterone reduction. The naturally occurring inositols display insulin-sensitizing effects and may be also used in this context because of their safety profile. Combined oral contraceptives represent the drug of choice for correction of androgen-related symptoms. Overall, PCOS management remains focused on specific targets including assessment and treatment of cardiometabolic risk, according to disease phenotypes. While new options are adding to established therapeutic approaches, a sometimes difficult balance between efficacy and safety of available medications has to be found in individual women.

Human Corticotropin-Releasing Hormone Tests: 10 Years of Real-Life Experience in Pituitary and Adrenal Disease.

CONTEXT: The human corticotropin-releasing hormone (CRH) test (hCRHtest) is used to differentiate Cushing disease (CD) from ectopic adrenocorticotropin (ACTH) secretion (EAS), to assess autonomous cortisol secretion by the adrenal glands, and to characterize pseudo-Cushing syndrome (CS) or adrenal insufficiency (AI). MAIN OUTCOME MEASURE: The main outcome measure of this study was to assess the diagnostic accuracy of the hCRHtest. METHODS: We measured ACTH and cortisol levels; collected the peak values (peakACTH and peakcortisol), and calculated the percentage increases (∆%ACTH and ∆%cortisol) after an intravenous bolus of 100 µg hCRH. DESIGN AND SETTING: This cross-sectional study of hCRH tests from 2010 to 2019 took place in a referral university hospital center. PATIENTS: We enrolled 200 patients: 86 CD, 15 EAS, 18 adrenal CS, 25 mild adrenal autonomous cortisol secretion, 31 pseudo-CS, and 25 suspected AI. RESULTS: The hCRHtest was performed mainly for the differential diagnosis of ACTH-dependent CS or adrenal lesions (P = .048). PeakACTH and peakcortisol were higher in CD, and ∆%ACTH and ∆%cortisol were able to differentiate CD from EAS with a sensitivity and specificity greater than 80%. In patients with low (< 10 pg/mL) or indeterminate (10-20 pg/mL) basalACTH levels, an absent or reduced peakACTH response was able to differentiate adrenal from ACTH-dependent forms. PeakACTH and peakcortisol after hCRHtest were lower in pseudo-CS than in CD, but ∆%ACTH and ∆%cortisol were similar. The role of hCRHtest in patients with AI was limited. CONCLUSIONS: The hCRHtest test is the mainstay of the differential diagnosis of ACTH-dependent CS. It is also useful for pointing to a diagnosis of CD in the event of bilateral adrenal masses, and in patients with low basalACTH.

Long-course temozolomide in aggressive pituitary adenoma: real-life experience in two tertiary care centers and review of the literature.

PURPOSE: Aggressive pituitary adenomas (APAs) and pituitary carcinomas (PCs) are challenging for their invasive nature, resistance to treatment and recurrences. Temozolomide (TMZ) is used with benefit and well-tolerated toxicity profile in APAs and PCs. In most studies patients received ≤ 12 cycles but the best length of treatment is debated since other options after discontinuation are scarce and a second course is mainly unsuccessful. METHODS: We report outcomes of 8 patients with APAs and PCs treated with TMZ for more than 12 continuous cycles with a literature review. Data were retrospectively collected from Padua and Milan University Hospitals. TMZ was used as a single agent (150-200 p.o. mg/m2 daily, 5/28 days) for 14 to 45 cycles. RESULTS: Eight patients (7 M), 7 APAs and 1 PC. Previous treatments included neurosurgery and radiotherapy in all cases except two giant masses (ACTH-silent APA and prolactinoma). No patient had progression disease (PD) during long-term treatment nor toxicities. No one had complete response (CR) but four had partial response (PR). Four ACTH+ tumors maintained stable disease (SD) but the secretion pattern improved in all. After drug withdrawal, three had delayed PD (2 after 18 and one after 29 months, all ACTH+); two are still in SD. CONCLUSIONS: TMZ may be useful and well-tolerated in APAs and PCs as a long-term therapy. PR appears within the first cycles with no escape throughout the treatment; most patients achieve SD. We suggest extended protocols particularly in responsive ACTH+ PAs and PCs, when further therapies may be unsuccessful.

The role of 68Ga-DOTA derivatives PET-CT in patients with ectopic ACTH syndrome.

INTRODUCTION AND AIM: Ectopic ACTH secretion (EAS) is mostly secondary to thoracic/abdominal neuroendocrine tumours (NETs) or small cell-lung carcinoma (SCLC). We studied the diagnostic accuracy of CT with 68Ga-Dota derivatives (68Ga-SSTR) PET in localizing ACTH-secreting tumor in patients with EAS. MATERIALS AND METHODS: 68Ga-SSTR-PET/CT was performed and compared with the nearest enhanced CT in 18 cases (16 primary and 2 recurrent neoplasms). Unspecific, indeterminate and false-positive uptakes were assessed using conventional imaging, follow-up or histology. RESULTS: We diagnosed 13 thoracic (9 primary and 2 recurrent bronchial carcinoids, 2 SCLCs) and 1 abdominal (pancreatic NET) tumors. Eight ACTH-secreting tumors were promptly identified at EAS diagnosis ('overt', four pulmonary carcinoids with two recurrences and two SCLC); six EAS have been discovered during the subsequent follow-up ('covert', five bronchial carcinoids and one pancreatic NET). At the time of EAS diagnosis, imaging was able to correctly detect the ACTH-secreting tumour in 8/18 cases (6 new diagnosis and 2 recurrences). During the follow-up, six out of initially ten 'occult' cases became 'covert'. At last available follow-up, CT and 68Ga-SSTR-PET/CT were able to diagnose 11/18 and 12/18 ACTH-secreting tumours, respectively (11/14 and 12/14 considering only overt and covert cases, respectively). Four cases have never been localized by conventional or nuclear imaging ('occult EAS'), despite an average follow-up of 5 years. CONCLUSION: The 68Ga-SSTR-PET/CT is useful in localizing EAS, especially to enhance positive prediction of the suggestive CT lesions and to detect occult neoplasms.

Allelic Variants of ARMC5 in Patients With Adrenal Incidentalomas and in Patients With Cushing's Syndrome Associated With Bilateral Adrenal Nodules.

Objective: Germline ARMC5 mutations are considered to be the main genetic cause of primary macronodular adrenal hyperplasia (PMAH). PMAH is associated with high variability of cortisol secretion caused from subclinical hypercortisolism to overt Cushing's syndrome (CS), in general due to bilateral adrenal nodules and rarely could also be due to non-synchronic unilateral adrenal nodules. The frequency of adrenal incidentalomas (AI) associated with PMAH is unknown. This study evaluated germline allelic variants of ARMC5 in patients with bilateral and unilateral AI and in patients with overt CS associated with bilateral adrenal nodules. Methods: We performed a retrospective multicenter study involving 123 patients with AI (64 bilateral; 59 unilateral). We also analyzed 20 patients with ACTH pituitary independent overt CS associated with bilateral adrenal nodules. All patients underwent germline genotyping analysis of ARMC5; abdominal CT and were classified as normal, possible or autonomous cortisol secretion, according to the low doses of dexamethasone suppression test. Results: We identified only one pathogenic allelic variant among the patients with bilateral AI. We did not identify any pathogenic allelic variants of ARMC5 in patients with unilateral AI. Thirteen out of 20 patients (65%) with overt CS and bilateral adrenal nodules were carriers of pathogenic germline ARMC5 allelic variants, all previously described. The germline ARMC5 mutation was observed in only one patient with bilateral AI; it was associated with autonomous cortisol secretion and showed to be a familial form. Conclusion: The rarity of germline ARMC5 mutations in AI points to other molecular mechanisms involved in this common adrenal disorder and should be investigated. In contrast, patients with overt Cushing's syndrome and bilateral adrenal nodules had the presence of ARMC5 mutations that were with high prevalence and similar to the literature. Therefore, we recommend the genetic analysis of ARMC5 for patients with established Cushing's syndrome and bilateral adrenal nodules rather than patients with unilateral AI.

The pathogenic role of the GIP/GIPR axis in human endocrine tumors: emerging clinical mechanisms beyond diabetes.

The glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone produced in the gastrointestinal tract in response to nutrients. GIP has a variety of effects on different systems, including the potentiation of insulin secretion from pancreatic ß-cells after food intake (i.e. incretin effect), which is probably the most important. GIP effects are mediated by the GIP receptor (GIPR), a G protein-coupled receptor expressed in several tissues, including islet ß-cells, adipocytes, bone cells, and brain. As well as its involvement in metabolic disorders (e.g. it contributes to the impaired postprandial insulin secretion in type 2 diabetes (T2DM), and to the pathogenesis of obesity and associated insulin resistance), an inappropriate GIP/GIPR axis activation of potential diagnostic and prognostic value has been reported in several endocrine tumors in recent years. The ectopic GIPR expression seen in patients with overt Cushing syndrome and primary bilateral macronodular adrenal hyperplasia or unilateral cortisol-producing adenoma has been associated with an inverse rhythm of cortisol secretion, with low fasting morning plasma levels that increase after eating. On the other hand, most acromegalic patients with an unusual GH response to oral glucose suppression have GIPR-positive somatotropinomas, and a milder phenotype, and are more responsive to medical treatment. Neuroendocrine tumors are characterized by a strong GIPR expression that may correlate positively or inversely with the proliferative index MIB-1, and that seems an attractive target for developing novel radioligands. The main purpose of this review is to summarize the role of the GIP/GIPR axis in endocrine neoplasia, in the experimental and the clinical settings.

New insights to the potential mechanisms driving coronary flow reserve impairment in Cushing's syndrome: A pilot noninvasive study by transthoracic Doppler echocardiography.

BACKGROUND: The contribution of functional and/or structural remodeling to reduced coronary flow velocity reserve (CFVR), reflecting impaired coronary microcirculation in Cushing's syndrome (CS), has not been clearly elucidated. We aimed to identify the potential mechanisms of coronary microvascular impairment in CS. METHODS: We studied 15 CS patients (11 female, age 50 ±â€¯9 years) without clinical evidence of cardiovascular disease. Coronary flow velocity in the left anterior descending coronary artery was measured by transthoracic Doppler echocardiography, at rest, and during adenosine infusion. Average peak flow velocities, CFVR, and microvascular resistance in baseline (BMR) and hyperemic conditions (HMR) were assessed. CFVR ≤2.5 was considered a marker of microvascular disease (CMD). Diastolic function (E/e'), global longitudinal strain (GLS) and fractional pulse pressure (fPP), an index of arterial stiffness, were also assessed. RESULTS: CMD was present in 5 patients (33.3%). CMD was primarily driven by increased baseline peak flow velocity (29 ±â€¯12 versus 19.6 ±â€¯4.2 cm/s, p = .03) in the presence of decreased BMR (3.62 ±â€¯0.6 versus 5.46 ±â€¯1.4 mm Hg·s/cm, p = .03). Moreover, urinary cortisol and E/e' were higher (p = .001 and p = .001, respectively) and GLS was lower (p = .009) in patients with CMD. fPP was higher in patients with CMD (p = .01). Urinary cortisol correlated to CFVR (p = .008), E/e' (p < .0001) and GLS (p < .0001). fPP directly correlated to average peak flow velocities at rest (p = .01) and inversely to BMR (p = .03). CONCLUSIONS: Functional microvascular regulatory impairment seems to be the potential mechanism of CMD in CS. CMD seems to be related to decreased myocardial contractility and diastolic dysfunction associated with cortisol excess.

Rapid disease progression in patient with mismatch-repair deficiency pituitary ACTH-secreting adenoma treated with checkpoint inhibitor pembrolizumab.

Secreting pituitary adenomas are tumors for which few treatment options are available, including surgical treatment and management of hormonal imbalance due to altered pituitary secretion. In case of inoperable relapse, radiotherapy or chemotherapeutic treatment can be considered; the effectiveness of these treatments, however, remains limited. In the immunotherapy era, it is necessary to select patients who can benefit from immunotherapeutic treatment. Mismatch repair deficiency is strongly associated with responsiveness to anti-PD-1 in other cancers and can be detected using immunohistochemistry for MLH1, MSH2, MHS6, and PMS2. In this case report, we report a case of rapid disease progression to pembrolizumab in a patient with a MMRd pituitary adrenocorticotropic hormone (ACTH)-secreting adenoma. For the best of our knowledge, we described for the first time, a poor efficacy of pembrolizumab in a patient with ACTH-secreting pituitary adenoma having mismatch repair deficiency probably caused by high levels of cortisol in this patient. Prospective study should be performed to assess the activity of immune checkpoint inhibitor alone or in association with temozolomide in this subsetting of pituitary adenomas.