Background: Corticotrophin-releasing hormone (CRH) is the major regulator of adrenocorticotrophic hormone (ACTH) secretion from the anterior pituitary and acts via CRH-1 receptors (CRH-1R). Corticotropinoma though autonomous, still retain their responsiveness to CRH and hence, we hypothesize that in vivo detection of CRH-1 receptors on pituitary adenoma using Gallium-68 (68Ga)-tagged CRH can indicate the functionality of adenoma, and combining it with positron emission tomography-computed tomography (PET-CT) can provide requisite anatomical information. Methods: Subjects with ACTH-dependent Cushing’s syndrome (CS) (n = 27, 24 with Cushing’s disease [CD], 3 with ectopic CS [ECS]) underwent 68Ga CRH PET-CT. Two nuclear medicine physicians read these images for adenoma delineation and superimposed them on magnetic resonance imaging (MRI) sella. The information provided was used for intraoperative navigation and compared with operative and histopathological findings. Findings: 68Ga CRH PET-CT correctly delineated corticotropinoma in all the 24 cases of CD, including the 10 cases with adenoma size < 6mm (4 cases were negative on MRI). Corticotropinoma location on 68Ga CRH PET fusion images with MRI were concordant with operative findings and were further confirmed on histopathology. There was no tracer uptake in the pituitary in 2 patients with ECS, while, in another, the diffuse uptake in pituitary suggested ectopic CRH production. Conclusion: 68Ga CRH PET-CT represents a novel, noninvasive molecular imaging, targeting CRH receptors that not only delineate corticotropinoma and provides the surgeon with valuable information for intraoperative tumor navigation, but also helps in differentiating a pituitary from an extra-pituitary source of ACTH-dependent CS. Funding: None.

Background Clinicians have long been struggling to find an effective tool to predict onset of puberty. Objective To explore stimulability of inhibin B after exogenous FSH and its potential role for prediction of onset of puberty. Design and participants Study subjects were enrolled into “exploratory cohort” (n = 42) and “validation cohort” (n = 19). The exploratory cohort was further divided into group 1 (healthy children with spontaneous puberty [SP], n = 26) and group 2 (patients with hypogonadotropic hypogonadism [HH], n = 16). The validation cohort included children who presented with complaints of delayed puberty. Intervention and outcome Participants were subjected to FSH stimulation test and GnRH analogue stimulation test. Cutoffs derived from the exploratory cohort for basal and FSH stimulated inhibin B (FSH-iB) were applied on the validation cohort. Basal LH, GnRH analogue-stimulated LH, basal inhibin B, and FSH-iB were compared with clinical outcomes on a prospective follow-up for prediction of onset of puberty. Results There was statistically significant increment in inhibin B after exogenous FSH in group 1 (SP) in both male (188.8 pg/mL; P = 0.002) and female (1065 pg/mL; P = 0.023) subjects. The increment was not statistically significant in group 2 (HH) in both sexes. FSH-iB at a cutoff of 116.14 pg/mL in males and 116.50 pg/mL in females had 100% sensitivity and specificity for labelling entry into puberty. On application of these cutoffs on the validation cohort, FSH-iB had 100% positive predictive value, negative predictive value, and diagnostic accuracy for prediction of pubertal onset. Conclusion Inhibin B was stimulable in both male and female subjects. FSH-iB can be considered a novel and promising investigation for prediction of onset of puberty. Future studies are required for further validation.

Adrenal adenomas/incidentalomas with mild autonomous cortisol secretion (MACS)/subclinical hypercortisolism (SH) are often associated with metabolic syndrome, glucocorticoid–induced osteoporosis, and fractures. In this background, the present systematic review and meta-analysis aimed to collate the available evidence and provide a summary of the effect of MACS/SH on bone health in terms of fractures, osteoporosis/osteopenia, microarchitecture, and bone turnover. PubMed/MEDLINE, Embase, and Web of Science databases were systematically searched for observational studies reporting prevalence of fractures, osteoporosis/osteopenia or data on bone microarchitecture/bone turnover markers (BTMs). Following literature search, 16 observational studies were included. Pooled prevalence of any fractures (vertebral and non–vertebral), vertebral fractures, and osteoporosis/osteopenia in MACS/SH were 43% [95% confidence intervals (CI): 23%, 62%], 45% (95% CI: 22%, 68%) and 50% (95% CI: 33%, 66%), respectively. On meta-regression, age, sex, 24-hour urinary free cortisol, and dehydroepiandrosterone-sulfate did not predict fracture risk. The likelihood of any fractures [odds ratio (OR) 1.61; 95% CI: 1.18, 2.20; P = 0.0026], vertebral fractures (OR 2.10; 95% CI: 1.28, 3.45; P = 0.0035), and osteoporosis/osteopenia (OR 1.46; 95% CI: 1.15, 1.85; P = 0.0018) was significantly higher in adrenal adenomas and MACS/SH than non–functional adrenal adenomas. Subjects with MACS/SH had significantly lower bone mineral density (BMD) at lumbar spine [mean difference (MD) −0.07 g/cm²; 95% CI: −0.11, −0.03; P = 0.0004) and femoral neck (MD -0.05 g/cm²; 95% CI: -0.08, −0.02; P = 0.0045) than their non–functional counterparts. Limited data showed no significant difference in BTMs. Publication bias was observed in the pooled prevalence of any fractures, vertebral fractures and pooled MD of femoral neck BMD. To conclude, people with adrenal adenomas/incidentalomas and MACS/SH are at a 1.5- to 2-fold higher likelihood of fractures and osteoporosis/osteopenia compared to non–functional adrenal adenomas and should routinely be screened for bone disease. Nevertheless, considering the modest sample size of studies and evidence of publication bias, larger and high–quality studies are required (CRD42023471045). Mild autonomous cortisol secretion (MACS), often also referred to as subclinical hypercortisolism (SH), is usually associated with an underlying adrenal incidentaloma (AI), an adrenal mass incidentally found during abdomen imaging. Although signs of overt cortisol excess are lacking, subjects with MACS/SH often have features of metabolic syndrome, osteoporosis and fractures. The present systematic review and meta-analysis showed that the pooled prevalence of any fractures (vertebral and non–vertebral), vertebral fractures, and osteoporosis/osteopenia in MACS/SH were 43%, 45%, and 50%, respectively. People with adrenal adenomas/incidentalomas and MACS/SH are at a 1.5- to 2-fold higher likelihood of fractures and osteoporosis/osteopenia compared to non–functional adrenal adenomas. Besides, subjects with MACS/SH had significantly lower bone mineral density at lumbar spine and femoral neck than their non–functional counterparts. It is thus imperative to assess bone health in all subjects with MACS/SH.

Context: Bilateral inferior petrosal sinus sampling (BIPSS) using hCRH is currently considered the ‘gold standard’ test for the differential diagnosis of ACTH-dependent Cushing’s syndrome (CS). Vasopressin is more potent than CRH to stimulate ACTH secretion as shown in animal studies; however, no comparative data of its use are available during BIPSS. Objective: To study the diagnostic accuracy and comparison of hCRH and lysine vasopressin (LVP) stimulation during BIPSS. Patients and methods: 29 patients (27-Cushing’s disease, 2-ectopic CS; confirmed on histopathology) underwent BIPSS and were included for the study. Patients were randomized to receive hCRH, 5 U LVP or 10 U LVP during BIPSS for ACTH stimulation. BIPSS and contrast-enhanced magnetic resonance imaging (CEMRI) were compared with intra-operative findings of trans-sphenoidal surgery (TSS) for localization and lateralization of the ACTH source. Results: BIPSS correctly localized the source of ACTH excess in 29/29 of the patients with accuracy of 26/26 patients, using any of the agent, whereas sensitivity and PPV for lateralization with hCRH, 5 U LVP and 10 U LVP was seen in 10/10, 6/10; 10/10,8/10 and 7/7,6/7 patients respectively. Concordance of BIPSS with TSS was seen in 20/27, CEMRI with BIPSS in 16/24 and CEMRI with TSS in 18/24 of patients for lateralizing the adenoma. Most of the side effects were transient and were comparable in all the three groups. Conclusion: BIPSS using either hCRH or LVP (5 U or 10 U) confirmed the source of ACTH excess in all the patients, while 10 U LVP correctly lateralized the pituitary adenoma in three fourth of the patients.

Introduction: Aggressive pituitary adenomas (APAs) are, by definition, resistant to optimal multimodality therapy. The challenge lies in their early recognition and timely management. Temozolomide is increasingly being used in patients with APAs, but evidence supporting a favorable response with early initiation is lacking.Methods: This was a single-center study of all patients with APAs who received at least 3 cycles of temozolomide (150–200 mg/m²). Their baseline clinico-biochemical and radiological profiles were recorded. Immunohistochemical evaluation for cell-cycle markers O⁶-methylguanine-DNA methyltransferase (MGMT), MutS homolog 2 (MSH2), MutS homolog 6 (MSH6), MutL homolog 1 (MLH1), and postmeiotic segregation increased 2 (PMS2) was performed, and h-scores (product of the number of positive cells and staining intensity) were calculated. Response was assessed in terms of radiological response using the RECIST criteria. Patients with controlled disease (≥30% reduction in tumor volume) were classified as responders.Results: The study comprised 35 patients (48.6% acromegaly, 37.1% prolactinomas, and 14.3% non-functioning pituitary adenomas). The median number of temozolomide (TMZ) cycles was 9 (IQR 6–14). Responders constituted 68.6% of the cohort and were more likely to have functional tumors, a lower percentage of MGMT-positive staining cells, and lower MGMT h-scores. There was a significantly longer lag period in the initiation of TMZ therapy in non-responders as compared with responders (median 36 vs. 15 months, p = 0.01). ROC-derived cutoffs of 31 months for the duration between diagnosis and TMZ initiation, low-to-intermediate MGMT positivity (40% tumor cells), and MGMT h-score of 80 all had a sensitivity exceeding 80% and a specificity exceeding 70% to predict response.Conclusion: Early initiation of TMZ therapy, functional tumors, and low MGMT h-score predict a favorable response to TMZ in APAs.