C-peptide level concomitant with hypoglycemia gives better performances than insulin for the diagnosis of endogenous hyperinsulinism: a single-center study of 159 fasting trials.

INTRODUCTION: Diagnosis of endogenous hyperinsulinism relies on the occurrence of a hypoglycemia, concomitant with inadequate high insulin and C-peptide levels. However, diagnostic cutoffs are not consensual among the different learned societies. The objective of this work was to propose optimized cutoffs for these three parameters for the diagnosis of endogenous hyperinsulinism. METHODS: All the patients having performed a fasting trial in Cochin Hospital Endocrinology Department between February 2012 and August 2022 were included. The results of glycemia, insulin and C-peptide levels during fasting trial were collected and analyzed. RESULTS: One hundred and fifty-nine patients were included: 26 with endogenous hyperinsulinism and 133 without endogenous hyperinsulinism. ROC analysis of glycemia nadir during fasting trial identified the value of 2.3 mmol/L as the optimal cutoff, ensuring a sensitivity of 100% associated with a specificity of 81%. ROC analysis of insulin and C-peptide levels concomitant with hypoglycemia <2.3 mmol/L showed very good diagnostic performances of both parameters with respective cutoffs of 3.1 mUI/L (=21.5 pmol/L; sensitivity = 96%; specificity = 92%) and 0.30 nmol/L (sensitivity = 96%; specificity = 100%). Insulin to glycemia ratio as well as C-peptide to glycemia ratio (in pmol/mmol) at the time of glycemia nadir did not show better diagnostic performances than C-peptide alone. CONCLUSION: A C-peptide level 0.3 nmol/L concomitant with a hypoglycemia <2.3 mmol/L appears as the best criterion to make the diagnosis of endogenous hyperinsulinism. Insulin level can be underestimated on hemolyzed blood samples, frequently observed in fasting trial, and thus shows lower diagnostic performances.

Pneumocystis pneumonia in patients with Cushing's syndrome: A French multicenter retrospective study.

OBJECTIVE: Pneumocystis pneumonia (PcP) is an opportunistic infection occurring in immunocompromised patients. Cushing's syndrome (CS) impairs the immune system, and several authors have reported PcP in patients with CS. The present study aimed to characterize PcP occurring in a CS context and its management in French tertiary centers, in order to highlight the similarities in clinical presentation and treatment according to whether prophylaxis is implemented or not. METHODS: This was a multicenter retrospective study conducted in several French University Hospitals and Cancer Centers. Patients with PcP and confirmed CS regardless of etiology were included. We excluded patients with other known causes of acquired immunodeficiency with increased risk of PcP. RESULTS: Twenty-five patients were included. CS etiology was neoplastic in 84.0% of cases. CS clinical presentation associated predominant catabolic signs (76.0%), hypokalemia (91.7%) and lymphopenia (89.5%). CS was intense in most patients, with mean plasma cortisol levels at diagnosis of 2.424±1.102nmol/L and urinary free cortisol>10× the upper limit of normal in 85.0%. In all patients, PcP onset followed introduction of cortisol blockers, at a median 5.5 days. Patients were treated with 1 to 3 cortisol blockers, mainly metyrapone (88%), which significatively lowered plasma cortisol levels to 667±541nmol/L at the onset of PcP (P<0.001). PcP occurred in 7 patients despite prophylaxis. Finally, 60.0% patients were admitted to intensive care, and 20.0% died of PcP. CONCLUSION: High mortality in patients with PcP implies that clinicians should be better informed about this rare infectious complication. Prophylaxis remains controversial, requiring comparative studies.

Differences in the spectrum of steroidogenic enzyme inhibition between Osilodrostat and Metyrapone in ACTH-dependent Cushing syndrome patients.

Introduction: Osilodrostat is a new 11ß-hydroxylase inhibitor with a mode of action analogous to Metyrapone. The objective of this study was to compare steroidogenic profiles in patients treated with either Osilodrostat or Metyrapone for adrenocorticotrophic hormone (ACTH)-dependent Cushing's syndrome (CS). Methods: Patients followed up at Cochin hospital Endocrinology department between March 2019 and December 2021 for an ACTH-dependent CS, controlled by either Osilodrostat or Metyrapone, were included. A serum profile of five steroids (cortisol, 11-deoxycortisol, 17-hydroxyprogesterone, androstenedione and testosterone) was determined using UPLC- tandem mass spectrometry (UPLC-MS/MS). Results: Nineteen patients treated with Osilodrostat, eight patients treated with Metyrapone and six patients treated with consecutive Metyrapone then Osilodrostat were included. Hypocortisolism (basal cortisol <100 nmol/L) was found in 48% of patients treated with Osilodrostat and 7% of patients treated with Metyrapone. 11-deoxycortisol and androstenedione levels were higher in patients treated with Metyrapone (80.9 (2.2-688.4) and 14.9 (2.5-54.3) nmol/L, respectively) than in patients treated with Osilodrostat (10.3 (0.5-71.9) and 4.0 (0.3-13.3) nmol/L) (P = 0.0009 and P = 0.0005). Testosterone level in women was also higher in Metyrapone group (3.3 (0.93-4.82) nmol/L vs 1.31(0.13-5.09) nmol/L, P = 0.0146). CYP11B1 activity (11-deoxycortisol/cortisol) was not significantly different between the two groups. CYP21A2 activity (17OHprogesterone/11-deoxycortisol) and CYP17A1 activity (17OHprogesterone/androstenedione) were significantly decreased in Osilodrostat group (P < 0.0001). Conclusion: In patients with ACTH-dependent CS, the use of CYP11B1 inhibitors in routine care suggests that Osilodrostat has a less specific effect on the inhibition of steroidogenic enzymes than Metyrapone. This might explain a smaller increase in 11-deoxycortisol and androgen levels in patients treated with Osilodrostat.

Identification of predictive criteria for pathogenic variants of primary bilateral macronodular adrenal hyperplasia (PBMAH) gene ARMC5 in 352 unselected patients.

Objective: Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a heterogeneous disease characterized by adrenal macronodules and variable levels of cortisol excess, with not clearly established clinical diagnostic criteria. It can be caused by ARMC5 germline pathogenic variants. In this study, we aimed to identify predictive criteria for ARMC5 variants. Methods: We included 352 consecutive index patients from 12 European centers, sequenced for germline ARMC5 alteration. Clinical, biological and imaging data were collected retrospectively. Results: 52 patients (14.8%) carried ARMC5 germline pathogenic variants and showed a more distinct phenotype than non-mutated patients for cortisol excess (24-h urinary free cortisol 2.32 vs 1.11-fold ULN, respectively, P < 0.001) and adrenal morphology (maximal adrenal diameter 104 vs 83 mm, respectively, P < 0.001) and were more often surgically or medically treated (67.9 vs 36.8%, respectively, P < 0.001). ARMC5-mutated patients showed a constant, bilateral adrenal involvement and at least a possible autonomous cortisol secretion (defined by a plasma cortisol after 1 mg dexamethasone suppression above 50 nmol/L), while these criteria were not systematic in WT patients (78.3%). The association of these two criteria holds a 100% sensitivity and a 100% negative predictive value for ARMC5 pathogenic variant. Conclusion: We report the largest series of index patients investigated for ARMC5 and confirm that ARMC5 pathogenic variants are associated with a more severe phenotype in most cases. To minimize negative ARMC5 screening, genotyping should be limited to clear bilateral adrenal involvement and autonomous cortisol secretion, with an optimum sensitivity for routine clinical practice. These findings will also help to better define PBMAH diagnostic criteria.

Redifferentiating Effect of Larotrectinib in NTRK-Rearranged Advanced Radioactive-Iodine Refractory Thyroid Cancer.

Metastatic thyroid cancers may dedifferentiate and become radioactive-iodine (RAI) resistant. A redifferentiating effect can be observed with inhibitors of the mitogen-activated protein kinase pathway in thyroid cancers with point mutation in oncogenes. This effect allows RAI reuptake that may lead to a therapeutic effect different from the antitumoral effect of the inhibitor. The potential redifferentiating effect of inhibitors targeting oncogenic fusion-genes was suggested by one adult and one pediatric patient using larotrectinib in NTRK-rearranged tumors. We report on three consecutive adult patients with metastatic RAI-resistant NTRK-rearranged thyroid cancer who received larotrectinib for disease progression and for whom the redifferentiating effect was examined. Larotrectinib-induced RAI reuptake in all or part of the metastatic disease for two patients and no reuptake was noted for the other patient. We demonstrate that redifferentiation of NTRK-rearranged RAI-resistant thyroid cancer with larotrectinib may exist but does not occur in all patients.

Amiodarone-induced thyrotoxicosis.

Amiodarone-induced thyrotoxicosis (AIT) are not uncommon endocrinopathies. Clinicians are sometimes faced with difficult diagnostic and therapeutic situations. The disease pathophysiology is partially understood, explaining the lack of predictive factors for occurrence. Different international recommendations for their management have been published: the most recent in 2018 by the European Thyroid Association (ETA) (Ross et al., 2016; Bartalena et al., 2018). The purpose of this paper is to present the essential concepts for their management and to review the literature since 2018.

18F-fluorocholine PET/CT in MEN1 Patients with Primary Hyperparathyroidism.

BACKGROUND: Primary hyperparathyroidism (HPT1) is the most frequent endocrinopathy in multiple endocrine neoplasia type 1 (MEN1). Its surgical management is challenging. We aimed to describe and compare the imaging findings of parathyroid ultrasound (US), sestaMIBI scintigraphy (sestaMIBI), and 18F-fluorocholine (FCH) PET/CT in a series of MEN1 patients with HPT1. METHODS: Retrospective analysis of a cohort of MEN1 patients with HPT1 assessed by parathyroid US, sestaMIBI scintigraphy and SPECT/CT, and FCH-PET/CT for potential surgery between 2015 and 2019. RESULTS: Twenty-two patients with a confirmed diagnosis of MEN1 who presented with HPT1 and were assessed by the 3 imaging modalities were included. After imaging workups, 11 patients were operated on for the first time, 4 underwent a redo surgery, and 7 did not undergo an operation. The overall patient-based positivity rate of imaging was 91% (20 of 22) for parathyroid US and 96% (21 of 22) for both sestaMIBI and FCH-PET/CT. The 3 imaging modalities demonstrated negative findings in 1/22 patient who did not undergo surgery. Overall, 3 pathologic glands were not detected by any imaging technique. SestaMIBI and FCH-PET/CT both resulted in the same 3 false-positive results in ectopic areas with a significant uptake on two thymic carcinoid tumors and one inflammatory lymph node. FCH-PET/CT provided more surgically relevant data than sestaMIBI in 4/11 patients with initial surgery and in 1/4 patient who underwent redo surgery. CONCLUSIONS: Compared to sestaMIBI scintigraphy, FCH-PET/CT provides additional information regarding the number of pathologic parathyroid glands and their localization in MEN1 patients with HPT1.

Prolonged response to 177Lu-DOTATATE therapy of a bone marrow infiltration in a refractory thymic neuro endocrine tumor.

Thymic neuro endocrine tumor (tNET) are extremely rare malignancies with poor prognosis, requiring investigation of novel therapeutic approaches. 177Lu-DOTATATE is a successful systemic treatment modality in patients with metastatic gastroenteropancreatic but it role in tNET is not yet well established. Here we report a case of a 39-year-old man with refractory bone marrow infiltration of a tNET, treated by 4 cycles of peptide receptor radionuclide therapy (PRRT) with 177Lu DOTATATE. Since the first cycle, clinical symptoms were substantially decreased, without any severe subacute haematological toxicity. Three months after the end of PRRT, both 68Ga-DOTATOC and 18F-FDG PET confirmed a partial response, already suggested by 177Lu-DOTATATE treatment scan with a significant decrease of the bone marrow uptake between the first and fourth cycle. This report highlights that PRRT could be an effective therapeutic option for advanced bone metastatic disease tNET, with the significant benefit of alleviation of bone pain and radiologic response, without severe or irreversible haematotoxicity.

False-Positive Results in 18F-Fluorocholine PET/CT for a Thymoma in Workup of a Hereditary Primary Hyperparathyroidism.

We present the case of a severe familial primary hyperparathyroidism related to a germline deletion in the HRPT2 (CDC73) gene. Morphological explorations revealed 2 potential hyperfunctioning parathyroid glands: a left cervical lesion on the neck ultrasound, and an ectopic mediastinal lesion on the parathyroid scintigraphy using Tc-methoxyisobutylisonitrile and on F-fluorocholine PET/CT. Surgery removal and histopathological examination determined that the mediastinal mass corresponded to a thymoma and the cervical lesion to a parathyroid adenoma. Those interesting images illustrate that a thymoma can produce false-positive results both on Tc-methoxyisobutylisonitrile scintigraphy and F-fluorocholine PET/CT.

Pituitary Lesion of Unknown Origin: Think Epithelioid Angiosarcoma.

Précis: We report the unusual etiology of a sellar aggressive mass, an epithelioid angiosarcoma, the diagnosis of which was made from positive epithelial and vascular markers.

DUSP5 and DUSP6, two ERK specific phosphatases, are markers of a higher MAPK signaling activation in BRAF mutated thyroid cancers.

BACKGROUND: Molecular alterations of the MAPK pathway are frequently observed in papillary thyroid carcinomas (PTCs). It leads to a constitutive activation of the signalling pathway through an increase in MEK and ERK phosphorylation. ERK is negatively feedback-regulated by Dual Specificity Phosphatases (DUSPs), especially two ERK-specific DUSPs, DUSP5 (nuclear) and DUSP6 (cytosolic). These negative MAPK regulators may play a role in thyroid carcinogenesis. METHODS: MAPK pathway activation was analyzed in 11 human thyroid cancer cell lines. Both phosphatases were studied in three PCCL3 rat thyroid cell lines that express doxycycline inducible PTC oncogenes (RET/PTC3, H-RASV12 or BRAFV600E). Expression levels of DUSP5 and DUSP6 were quantified in 39 human PTCs. The functional role of DUSP5 and DUSP6 was investigated through their silencing in two human BRAFV600E carcinoma cell lines. RESULTS: BRAFV600E human thyroid cancer cell lines expressed higher phospho-MEK levels but not higher phospho-ERK levels. DUSP5 and DUSP6 are specifically induced by the MEK-ERK pathway in the three PTC oncogenes inducible thyroid cell lines. This negative feedback loop explains the tight regulation of p-ERK levels. DUSP5 and DUSP6 mRNA are overexpressed in human PTCs, especially in BRAFV600E mutated PTCs. DUSP5 and/or DUSP6 siRNA inactivation did not affect proliferation in two BRAFV600E mutated cell lines, which may be explained by a compensatory increase in other phosphatases. In the light of this, we observed a marked DUSP6 upregulation upon DUSP5 inactivation. Despite this, DUSP5 and DUSP6 positively control cell migration and invasion. CONCLUSIONS: Our results are in favor of a stronger activation of the MAPK pathway in BRAFV600E PTCs. DUSP5 and DUSP6 have pro-tumorigenic properties in two BRAFV600E PTC cell line models.

Long-Term Control of Hypercortisolism by Vandetanib in a Case of Medullary Thyroid Carcinoma with a Somatic RET Mutation.

BACKGROUND: Medullary thyroid carcinomas (MTCs) complicated by ectopic Cushing's syndrome (CS) have a poor prognosis, partially due to the difficulty in controlling hypercortisolism by adrenal blocking drugs. Recent reports (including the initial follow-up of this patient) have suggested that tyrosine kinase inhibitors (TKIs) may be a therapeutic option due to an anti-secretory action on ACTH. However, there is a lack of long-term follow-up studies. PATIENT FINDINGS: The case is reported of a 58-year-old man with MTC-related CS resistant to a combination of several anti-cortisolic drugs. Vandetanib, an oral multi-TKI that targets RET in particular, was initiated, and a rapid reversal of the hypercortisolism was observed without any change in tumor size. Vandetanib was briefly interrupted twice, once for 45 days because of side effects and a second time for 10 days to schedule surgical debulking. Each time, plasma cortisol and calcitonin levels increased after TKI withdrawal and were rapidly lowered by vandetanib reintroduction. As described in other cases of CS caused by MTC, a marked ACTH increase after desmopressin stimulation was observed before vandetanib therapy. In contrast, a blunted ACTH response to desmopressin was documented throughout the course of vandetanib treatment. This modulation of the tumoral ACTH production is a strong argument in favor of a TKI anti-secretory action. A left thyroid lobectomy and a modified neck dissection were performed one year after the initiation of vandetanib in order to reduce the tumor mass. An activating M918T RET (c.2753T>C) somatic mutation was identified in a lymph node metastasis. CONCLUSION: Three years and eight months after vandetanib initiation, there was no sign of recurrence of hypercortisolism. This case illustrates the long-term effectiveness of vandetanib in maintaining the control of hypercortisolism in MTC-related CS.

Dual Specificity Phosphatase 5, a Specific Negative Regulator of ERK Signaling, Is Induced by Serum Response Factor and Elk-1 Transcription Factor.

Serum stimulation of mammalian cells induces, via the MAPK pathway, the nuclear protein DUSP5 (dual-specificity phosphatase 5), which specifically interacts with and inactivates the ERK1/2 MAP kinases. However, molecular mechanisms underlying DUSP5 induction are not well known. Here, we found that the DUSP5 mRNA induction depends on a transcriptional regulation by the MAPK pathway, without any modification of the mRNA stability. Two contiguous CArG boxes that bind serum response factor (SRF) were found in a 1 Kb promoter region, as well as several E twenty-six transcription factor family binding sites (EBS). These sites potentially bind Elk-1, a transcription factor activated by ERK1/2. Using wild type or mutated DUSP5 promoter reporters, we demonstrated that SRF plays a crucial role in serum induction of DUSP5 promoter activity, the proximal CArG box being important for SRF binding in vitro and in living cells. Moreover, in vitro and in vivo binding data of Elk-1 to the same promoter region further demonstrate a role for Elk-1 in the transcriptional regulation of DUSP5. SRF and Elk-1 form a ternary complex (Elk-1-SRF-DNA) on DUSP5 promoter, consequently providing a link to an important negative feedback tightly regulating phosphorylated ERK levels.

The Great Imitator in Endocrinology: A Painful Hypophysitis Mimicking a Pituitary Tumor.

CONTEXT: The incidence of syphilis has been increasing in recent decades in Western countries. Pituitary involvement is very unusual in syphilis. This infectious disease is not often considered in the workup of a patient with hypophysitis. CASE: We report the case of a 28-year-old man who was admitted for headaches worsening over 1 month that became resistant to paracetamol. A magnetic resonance imaging scan revealed a heterogeneous pituitary mass suggesting a pituitary tumor. Hormonal investigations showed partial corticotropic and thyrotropic deficiencies. Headaches required high doses of morphine. Transsphenoidal surgery was performed, and histological examination revealed an aspect of hypophysitis. One month later, clinical reexamination showed skin and tongue lesions very suggestive of a syphilis infection, which was serologically confirmed. Immunohistochemistry on paraffin sections of the resected pituitary revealed an abundant presence of Treponema pallidum, confirming the diagnosis of a syphilitic hypophysitis. Intravenous therapy by benzylpenicillin for 14 days was rapidly efficient. Headaches stopped within a few days, and the skin and tongue lesions disappeared during the following month. Thyrotropic deficiency resolved in 2 weeks, but partial corticotropic deficiency persisted at 3 months. CONCLUSION: This is the first case of a pituitary involvement in acquired syphilis, pathologically proven, in a non-HIV-infected patient. In a context of the resurgence of syphilis, this diagnosis should be considered in the case of a pituitary lesion with unusually intense headaches.

[Premature ovarian failures]. / Insuffisances ovariennes prématurées.

Premature ovarian failure (POF) is clinically suspected by amenorrhea and confirmed by an elevated FSH serum level above 40 mUI/L (even 20 mUI/L) twice, in a woman before the age of 40. Prevalence of POF is between 1 to 2% in women. In 90% of cases, no aetiology is identified. Obvious causes are chemotherapy, pelvic radiotherapy, ovarian surgery and diethylstilbestrol exposure in utero. A karyotype should be performed as Turner Syndrome is the most frequent genetic cause of POF. Some X abnormalities such as X deletion or X autosome translocation can be found. FMR1 pre-mutation (fragile X syndrome) should be searched for, even though no cases of mental retardation are known, in the family. Other genetic abnormalities can be suggested by associated symptoms (i.e.: FOXL2, SF1 mutations). Auto-immune aetiology can be suspected if other auto-immune features are present, however, there are no reliable auto-antibodies to confirm auto-immunity in POF. Treatment of POF is based on hormonal replacement therapy in order to avoid estrogen deficiency, suppress vasomotor symptoms and avoid bone loss as well as cardiovascular risk. Estrogens should be associated with progesterone or a progestin, at least up to the age of 51. Patients with POF should be informed that spontaneous pregnancies may occur (in 5% of cases). In case of desire of pregnancy, the patient should be oriented to a specialized unit for in vitro fertilization with oocyte donation. Psychological support is essential and should be part of the treatment. POF is associated with an increased risk of emotional distress and depression. No preventive treatment of POF is available so far.

Frequent large germline HRPT2 deletions in a French National cohort of patients with primary hyperparathyroidism.

CONTEXT: Hyperparathyroidism-jaw tumor syndrome (HPT-JT) is an autosomal dominant syndrome with incomplete penetrance that can associate in a single patient parathyroid adenoma or carcinoma, fibro-osseous jaw tumor, cystic kidney lesion, and uterine tumor. Germline mutations of the HRPT2 gene (CDC73) coding for parafibromin are identified in approximately 50%-75% of HPT-JT cases and in approximately 14% of familial isolated hyperparathyroidism. A whole deletion of this gene has recently been reported in 1 sporadic case and in a family presenting with HPT-JT. OBJECTIVE: The objective of the study was to report molecular abnormalities of the HRPT2 gene in patients with primary hyperparathyroidism in a French National cohort from the Groupe d'Étude des Tumeurs Endocrines. METHODS: Patients' genomic DNA was screened by PCR-based sequencing for point mutations affecting HRPT2 and real-time quantitative PCR analysis for gross deletions. RESULTS: We report 20 index patients with a germinal HRPT2 abnormality. Median age at diagnosis of primary hyperparathyroidism was 23 years (range 14-65 years). Median serum total calcium level at diagnosis was 3.19 mmol/L (range 2.8-4.3 mmol/L). Thirteen different mutations were identified by routine sequencing, including 7 mutations never reported. Seven patients (35%) carried a gross deletion of this gene (3 complete and 4 partial deletions). No genotype-phenotype correlation could be identified. A gross deletion of the HRPT2 gene was identified in 7% of patients for whom a routine screening by direct sequencing came up as negative. CONCLUSION: Gross deletion analysis of the HRPT2 gene is indicated for all patients negative for mutation, presenting with HPT-JT or familial isolated hyperparathyroidism, parathyroid carcinoma, or in patients with apparently sporadic parathyroid adenoma diagnosed at a young age, having a severe hypercalcemia.

A new contraceptive pill containing 17ß-estradiol and nomegestrol acetate.

Most combined oral contraceptive pills contain ethinyl estradiol (EE) with progestins. In order to minimize the pill's cardiovascular risks, the concept of using 17ß-estradiol (E2), the endogenous estradiol, arose in the 1970s. Many attempts to develop a pill containing 17ß-E2 have failed as cycle control was low. The first pill containing 17ß-E2 was launched in 2011. This monophasic pill contains 24 pills with 1.5 mg 17ß-E2 and 2.5 mg nomegestrol acetate, and four placebo pills. Studies conducted in Europe and the USA demonstrate that its Pearl index is 0.38 and 1.13, respectively. It has less influence on hemostasis, fibrinolysis markers, lipids and carbohydrate metabolism than the combined oral contraceptive levonorgestrel/EE (150 g/30 g and 100 µg/20 µg). Withdrawal bleedings are shorter and lighter as compared with women using drospirenone/EE (3 mg/ 30 µg). The number of women without withdrawal bleeding is approximately 30% after 12 months. Even though its contraindications are identical to other combined oral contraceptives, this nomegestrol acetate/E2 pill should be considered to be of interest for many women.