CRH Test Research Articles

8356 Total Hypophysectomy in Cushing’s Disease: Results from a Terciary Center

Abstract Disclosure: M.V. Lopes: None. M.D. Severino: None. J. Rocha: None. C.R. Peixe: None. M.I. Alexandre: None. A. Gomes: None. M.J. Bugalho: None. Introduction: Transsphenoidal surgery (TSS) is the first line treatment for Cushing’s disease (CD), leading to remission in 70-80% of cases. Though selective adenomectomy is the preferred approach, total hypophysectomy may be needed. Objective: To describe 3 CD patients in which total hypophysectomy was performed. Clinical cases 1. A 58-year-old man with a history of type 2 diabetes (T2D) and obesity, was referred to the Endocrinology Clinic due to abdominal purple striae and facial plethora. Laboratory tests suggested ACTH dependent hypercortisolism, with normal serum ACTH, high 24h urinary cortisol and no cortisol suppression in the overnight 1mg dexamethasone suppression test (DST). The CRH test was suggestive of CD but no adenoma was found on pituitary MRI. Inferior petrosal sinus sampling (IPSS) was compatible with CD with right-sided lateralization. Right hypophysectomy was performed but no CD remission was achieved, so the patient underwent total hypophysectomy. Corticotroph hyperplasia was identified in histology. After 9 months of follow-up, he mantains CD remission. 2.A 37-year-old woman was diagnosed with ACTH dependent hypercortisolism after referral to the Endocrinology Clinic for alopecia, amenorrhea, hypertension and hirsutism. Laboratory tests showed severe hypokalemia, high plasma ACTH and 24h urinary cortisol and the MRI showed a right-sided macroadenoma. Nonetheless, considering the clinical severity, an IPSS was performed and definitely excluded an ectopic Cushing’s syndrome (CS) thus confirming the diagnosis of CD with right-sided lateralization. The patient underwent selective TSS, however, for lack of CD remission, total hypophysectomy was performed. Histology revealed an adenocorticotrophic adenoma. Yet, a year later, she maintains persistence of CD, although less severe, and is under treatment with metyrapone. 3.A 58-year-old woman with a history of T2D and class 3 obesity, was evaluated in our Endocrinology Clinic due to obesity. Her physical examination suggested CS, so this hypothesis was investigated. Laboratory tests suggested ACTH dependent hypercortisolism, with normal serum ACTH, elevated 24h urinary cortisol and no cortisol suppression in the overnight 1mg DST. The high dose DST was suggestive of CD but the pituitary MRI didn’t show an adenoma. IPSS was compatible with CD but it was not possible to determine lateralization. So, total hypophysectomy was performed. An adenocorticotrophic adenoma was identified in histology. Postoperative CD remission was achieved and persists 3 months later. Conclusions: These 3 cases highlight the challenge of treating CD and suggest that in certain cases total hypophysectomy may be the treatment of choice to cure or at least improve CD. Although it is associated with more complications than selective TSS, our patients had no complications, only developed panhypopituitarism and diabetes insipidus. Presentation: 6/1/2024

The Differential Diagnosis between Cushing's Disease and Pseudocushing Syndrome in a Pre-agonic Patient.

The pseudo-Cushing's encompass several disorders that can occur in high-stress situations and that show biochemical features like those of Cushing's syndrome. We present a case with difficult differential diagnosis for overlapping laboratory findings. A 74-year-old man was admitted to our hospital for worsening dyspnoea for a month, 15 kilograms of weight loss in the previous months, asthenia, hypotonia, and muscle hypotrophy. Moreover, due to the onset of acute hypoxic-hypercapnic respiratory failure, the patient was treated with non-invasive ventilation and then admitted to the intensive care unit, for pneumonia and respiratory failure due to Meticillin-sensitive Staphylococcus aureus and Klebsiella Aerogenes. Antibiotic therapy was started. During the treatment in the ICU, the patient underwent endotracheal intubation for the worsening of respiratory function, and inotropic drug therapy was introduced for the development of septic shock. Hormones were tested, showing an ACTH-dependent hypercortisolism. The results of Nugent, Liddle, and the dexamethasone- suppressed CRH stimulation tests suggested a not-neoplastic ACTH-dependent hypercortisolism. The pituitary contrasted magnetic resonance image showed gland hypertrophy, and the abdominal computed tomography ruled out adrenal lesions. Unfortunately, the patient developed a multi-organ failure and died. The autopsy finding confirmed the absence of pituitary and other neuroendocrine tumors and showed bilateral adrenal hypotrophy. Our clinical case described a patient with pseudo-Cushing's syndrome during sepsis and pre-agonist phase, with a difficult differential diagnosis, in which the combination of the low-dose dexamethasone suppression test and the CRH test allowed a conclusive and correct diagnostic orientation.

Personalized Noninvasive Diagnostic Algorithms Based on Urinary Free Cortisol in ACTH-dependant Cushing's Syndrome.

Current guidelines for distinguishing Cushing's disease (CD) from ectopic ACTH secretion (EAS) are questionable, as they use pituitary magnetic resonance imaging (MRI) as first-line investigation for all patients. CRH testing is no longer available, and they suggest performing inferior petrosal sinus sampling (BIPPS), an invasive and rarely available investigation, in many patients. To establish noninvasive personalized diagnostic strategies based on the probability of EAS estimated from simple baseline parameters. Retrospective study. University hospitals. Two hundred forty-seven CD and 36 EAS patients evaluated between 2001 and 2023 in 2 French hospitals. A single-center cohort of 105 Belgian patients served as external validation. Twenty-four-hour urinary free cortisol (UFC) had the highest area under the receiver operating characteristic curve for discrimination of CD from EAS (.96 [95% confidence interval (CI), .92-.99] in the primary study and .99 [95% CI, .98-1.00] in the validation cohort). The addition of clinical, imaging, and biochemical parameters did not improve EAS prediction over UFC alone, with only BIPPS showing a modest improvement (C-statistic index .99 [95% CI, .97-1.00]). Three groups were defined based on baseline UFC: < 3 (group 1), 3-10 (group 2), and > 10 × the upper limit of normal (group 3), and they were associated with 0%, 6.1%, and 66.7% prevalence of EAS, respectively. Diagnostic approaches performed in our cohort support the use of pituitary MRI alone in group 1, MRI first followed by neck-to-pelvis computed tomography scan (npCT) when negative in group 2, and npCT first followed by pituitary MRI when negative in group 3. When not combined with the CRH test, the desmopressin test has limited diagnostic value. UFC accurately predicts EAS and can serve to define personalized and noninvasive diagnostic algorithms.

Mutual associations among responsiveness to differential diagnostic tests for Cushing's disease, tumor size, and somatostatin receptor 5 expression in corticotroph tumors.

There are differences in the responsiveness to differential diagnostic tests for Cushing's disease (CD), corticotroph tumor size, and the somatostatin receptor (SSTR) 5 expression in corticotroph tumors between CD patients. The differences in SSTR5 expression are particularly significant for identifying therapeutic targets for CD. However, prospective predictors of SSTR5 expression remain unclear. Thus, our objective was to elucidate the relationships among these clinical characteristics of CD, including SSTR5 expression. In 27 hospitalized patients with CD at Osaka University Hospital, Osaka, Japan, associations between corticotroph tumor diameter, the response of ACTH and cortisol to differential diagnostic tests for CD (CRH, desmopressin [DDAVP], and high-dose dexamethasone suppression test [HDDST]), the ACTH/cortisol index, and the SSTR5 immunoreactive score were retrospectively investigated. The response to differential diagnostic tests, ACTH/cortisol index, tumor diameter, and SSTR5 expression were significantly related (vs. tumor diameter [CRH: r = -0.54; DDAVP: r = -0.54; HDDST r = -0.67; ACTH/cortisol index: r = 0.76; SSTR5: r = -0.61], vs. CRH [DDAVP: r = 0.63, HDDST: r = 0.72, ACTH/cortisol index: r = -0.45; SSTR5: r = 0.56], vs. DDAVP [HDDST: r = 0.66; ACTH/cortisol index: r = -0.46; SSTR5: r = 0.76], vs. HDDST [ACTH/cortisol index: r = -0.62; SSTR5: r = 0.77], ACTH/cortisol index vs. SSTR5: r = -0.67). The areas under the receiver operating characteristic curve for the prediction of high SSTR5 expression via the CRH test, DDAVP test, HDDST, ACTH/cortisol index, and tumor diameter were 0.79, 0.87, 0.80, 0.71, and 0.71, respectively. Tests for differential diagnosis of CD, the ACTH/cortisol index, and the corticotroph tumor diameter have the potential for identifying SSTR5 expression in corticotroph tumors. These parameters may reflect the biological characteristics of corticotroph tumors.

THU030 Evaluation Of Combined CRH And HDDST Test Performance

Abstract Disclosure: H. Elenius: None. R. McGlotten: None. L.K. Nieman: None. Introduction: Determining the etiology of ACTH-dependent Cushing’s Syndrome (CS) is frequently a diagnostic challenge. Non-invasive tests to distinguish Cushing’s Disease (CD) from Ectopic ACTH Syndrome (EAS) are the CRH stimulation test and the 8 mg overnight high dose dexamethasone suppression test (HDDST). The CRH test is more accurate (sensitivity (Se) 83-93%, specificity (Sp) 85-100%) than the HDDST (Se 56-95%, Sp 67-100%), depending on the type of CRH and criteria used. We retrospectively reviewed the results of each test at our institution between 2005-2019 to evaluate the tests' performance at established cut offs, identify optimal response criteria and to see whether combining the two tests provided additional diagnostic accuracy. Methods: CD or EAS was confirmed by either surgical pathology or biochemical cure after tumor resection or imputed from IPSS results (n=7). We identified 100 patients with CD and 34 with EAS. Two EAS patients with cyclic CS each underwent tests with or without active hypercortisolism. Test criteria to identify CD were ≥50% suppression of cortisol for the HDDST and a ≥35% increase in mean ACTH at 15-30 minutes or a ≥20% increase in mean cortisol at 30-45 minutes for the ovine CRH test. Results: The HDDST had a Se of 81%, Sp of 81% and diagnostic accuracy (DA) of 81%, while the CRH test had Se 95%, Sp 75% and DA 90%. Each test improved with modified response criteria. Using a HDDST suppression criterion of ≥63% gave Se 78%, Sp 89% and DA 81%. Using CRH test response criteria of ≥39% increase in ACTH or ≥30% increase in cortisol gave Se 94%, Sp 92% and DA 93%. Performance improved further by combining the two tests, using the optimized criteria (≥63% for HDDST and ≥39% or ≥30% for the CRH test). Test results were concordant in 80%, giving a Se of 96%, Sp 97% and DA 96%. Among EAS patients, this approach only misidentified one subject with cyclic CS who was tested while hypocortisolemic. Removing this test improved combined test performance to Se 96%, Sp 100% and DA 97%. Among the 26 patients with discordant results (CD = 22, EAS = 4), the HDDST result was likelier to be correct in EAS vs CD (50% vs 14%, PPV 60%), while the CRH test was more often correct in CD vs EAS (86% vs 50%, PPV 90%). Conclusions: Based on this series that included a large proportion of EAS patients, the CRH test performed better than the HDDST, in line with earlier data. In cyclic CS, tests performed better in hypercortisolemic patients. The optimal response criteria were ≥63% cortisol suppression for HDDST and ≥39% ACTH or ≥30% cortisol increase for the CRH test. In the 81% of hypercortisolemic cases with concordant test results, these combined optimized cut offs provided the best diagnostic performance, improving it to Se 96%, Sp 100%, DA 97%. When results were discordant, the CRH test worked better to identify patients with CD. Presentation: Thursday, June 15, 2023

SAT321 Ectopic ACTH Cushing's Syndrome Caused By A Large-cell Neuroendocrine Lung Carcinoma Responding To Desmopressin

Abstract Disclosure: S. Larose: None. D. Rioux: None. R. Albadine: None. A. Lacroix: None. Background: Ectopic ACTH secretion (EAS) is a less frequent cause of ACTH-dependent Cushing’s syndrome (CS), most often caused by a thoracic neuroendocrine tumor (NET). Large-cell neuroendocrine carcinomas (LCNEC) with EAS are rare and usually present a more severe phenotype of ACTH secretion and hypercortisolism. Clinical Case: We report the case of a 44-yo non-smoking man, who presented clinical and biochemical evidence of ACTH-dependent severe CS complicated by pulmonary emboli. In the context of an initial equivocal pituitary MRI, desmopressin and CRH stimulation tests were performed. Desmopressin produced a 157% increase in ACTH (basal: 59.0 pmol/L to peak: 151.9 pmol/L) and a 25% increase in cortisol from baseline; there was no stimulation of ACTH or cortisol during a CRH test and no suppression with high dose dexamethasone tests. Repeat pituitary MRI identified a 5 mm lesion, but inferior petrosal venous sinus sampling (IPSS) under desmopressin did not identify a central ACTH source. Thorax and abdominal imaging including Indium-111 octreoscan identified a left lung 3 mm micronodule which became more evident when pulmonary emboli resolved. In this context of probable ectopic ACTH secretion, the patient was treated with left inferior lung lobectomy for a suspected NET. Pathological studies confirmed a lung LCNEC with morphologic features of carcinoid tumor and strongly positive ACTH immunohistochemistry (IHC) in the primary lesion and lymph node metastasis. The patient was in CS remission after surgery and adjuvant chemotherapy, but developed a CS recurrence 9.5 years later, with a morning ACTH of 56.9 pmol/L, (N &amp;lt;11.0 pmol/L), a non-suppressed AM cortisol of 633 nmol/L after 1mg of dexamethasone overnight and urinary free cortisol of 1717 nmol/24 hours (N:&amp;lt; 789). Imaging showed signs of recurrence, with a hypermetabolic, 14 x 11 mm left hilar lymph node lesion on a TEP-DOTATATE scan in the left lung, near the surgical suture. An endobronchial ultrasound-guided biopsy confirmed the recurrence of the LCNEC. Surgery was performed and demonstrated again positive ACTH IHC of the lesion. The patient achieved remission of CS with secondary adrenal insufficiency, treated with hydrocortisone. Six months later, there was no response of ACTH or cortisol to a desmopressin test. Conclusion: This is the first report of LCNEC with morphologic feature of carcinoid tumor of the lung with ectopic ACTH secretion stimulated by desmopressin. Long delay prior to metastatic recurrence indicates relatively indolent NET. This case report indicates that response to desmopressin can occur in malignant LCNEC. Combining the desmopressin test with other dynamic tests, sellar MRI, IPSS and thoraco-abdominal functional imaging improves diagnostic accuracy of ectopic ACTH source. Presentation: Saturday, June 17, 2023

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

Determining the etiology of adrenocorticotropin (ACTH)-dependent Cushing's syndrome (CS) is often difficult. The gold standard test, inferior petrosal sinus sampling (IPSS), is expensive and not widely available. Evaluate the performance of the corticotropin-releasing hormone stimulation test (CRH-ST) and the 8 mg high-dose dexamethasone suppression test (HDDST) in distinguishing Cushing's disease (CD) from ectopic ACTH syndrome (EAS). Retrospective review in a tertiary referral center. A total of 323 patients with CD or EAS (n = 78) confirmed by pathology or biochemical cure (n = 15) in 96% underwent CRH-ST and HDDST performed between 1986 and 2019. We calculated test sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value, and diagnostic accuracy (DA) for the diagnosis of CD, and determined optimal response criteria for each test, alone and in combination. The CRH-ST performed better than the HDDST (DA 91%, 95% CI 87-94% vs 75%, 95% CI 69-79%). Optimal response criteria were a ≥40% increase of ACTH and/or cortisol during the CRH test and a ≥69% suppression of cortisol during the HDDST. A ≥40% cortisol increase during the CRH test was the most specific measure, PPV 99%. Seventy-four percent of subjects had concordant positive CRH test and HDDST results, yielding Se 93%, Sp 98%, DA 95%, and PPV 99%, with a pretest likelihood of 85%. A proposed algorithm diagnosed 64% of patients with CD with near perfect accuracy (99%), obviating the need for IPSS. CRH is a valuable tool to correctly diagnose the etiology of ACTH-dependent CS. Its current worldwide unavailability impedes optimal management of these patients.

The role of CRH test in predicting the efficacy of unilateral adrenalectomy in Bilateral Macronodular Adrenal Hyperplasia

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

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

Early prediction of hypothalamic-pituitary-adrenal (HPA) axis function following transsphenoidal surgery (TSS) can improve patient safety and reduce costs. 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. Retrospective analysis of clinical data between August 2015 and May 2022. Referral center. Consecutive patients (n = 129) undergoing TSS who had perioperative ACTH and cortisol measurements. ACTH and cortisol measurement at extubation. Further serial 6-hourly measurements in CD patients. Prediction of future HPA axis status based on ACTH/cortisol at extubation. 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. 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.

Food-dependent Cushing's syndrome due to unilateral adrenocortical adenoma with cortisol secretion without ACTH elevation detected in peripheral blood by the CRH test: a case report.

We report an extremely rare case of a 61-year old woman with food-dependent Cushing's syndrome (FDC) due to unilateral adrenocortical adenoma (UAA) with cortisol (CORT) secretion without ACTH elevation detected in peripheral blood by the CRH test. She was on oral medications for hypertension and depression, and presented weight gain, general fatigue, muscle weakness, and hypokalemia. Despite the fact that the diurnal variation of ACTH was always suppressed, a diurnal variation in CORT was observed, in the form of low levels in the early morning and high levels in the afternoon. An increase in CORT was shown in a 75 g-oral glucose tolerance test (OGTT) and in a mixed meal tolerance test, but no change in CORT levels was seen in intravenous glucose tolerance tests. Elevated CORT levels were observed in response to intravenous injection of CRH, although ACTH levels were always below the measured sensitivity. Laparoscopic left adrenalectomy was performed, which resulted in postoperative improvement in potassium and ACTH levels and disappearance of the CORT secretory response in the OGTT. Clear expression of glucose-dependent insulinotropic polypeptide receptor (GIPR), CRH and CRH receptor 2 (CRHR2) were confirmed in the surgically-resected UAA specimen by molecular and immunohistochemical analyses, suggesting the involvement of not only GIPR, but also CRH and CRHR2 in FDC.

Relevance of inferior petrosal sinus sampling in the diagnosis of Cushing's syndrome: a case report.

Non-specific signs and symptoms of Cushing's syndrome (CS) can pose a diagnostic challenge. We report the case of a man referred to the service of endocrinology for suspected CS. Hypercortisolism was confirmed on CS screening tests, whereas diagnostic tests confirmed the presence of adrenocorticotropin (ACTH) -dependent CS. The corticotropin-releasing hormone stimulation (CRH) test was performed to determine whether CS hadan endogenous or ectopic origin. Since the CRH and the magnetic resonance imaging (MRI) test were negative, IPSS was performed and suggested that CS was originated in the pituitary glands. Transsphenoidal pituitary resection was carried out. Histopathological analysis confirmed the cortitotrope origin of the tumor. The etiological study and differential diagnosis of CS are complex processes that involve a variety of biochemical and imaging tests. It is important that a sequence of biochemical screening and diagnostic tests is performed, along with studies for establishing the location of the lesion, to determine whether CS has an adrenal, pituitary or ectopic origin. Despite its good diagnostic performance, the results of biochemical tests may not be conclusive, especially in ACTH-dependent CS. In the case reported, the inconclusive results obtained in the CRH test rendered an invasive procedure (IPSS) necessary, which ultimately confirmed diagnosis.

ODP309 Ectopic Cushing's Syndrome: Importance of Methodical Approach to Hide and Seek

Abstract Cushing's syndrome (CS) is associated with high morbidity and fivefold excess mortality. Ectopic ACTH syndrome accounts for 20% of CS cases. It is crucial to identify and localize the source of extrapituitary ACTH secretion because surgical resection of the primary, often malignant, tumor has a high probability of cure with complete remission in 80% of cases. A 72-year-old female was admitted to a community hospital for lateral chest pain after a fall. She endorsed progressive weight gain, new HTN, emotional lability and worsening cognition over the prior 6 months. ACTH and cortisol levels were elevated. MRI brain failed to identify a pituitary lesion. CT chest showed multiple rib fractures and anterior mediastinal mass which was biopsied. While awaiting pathology results, IPS sampling attempted but aborted due to pulmonary edema necessitating ICU care. She was transferred to our institution for planned TSR of suspected pituitary adenoma. Examination showed Cushingoid features. Labs showed hypokalemia, high cortisol and high ACTH. MRI pituitary showed normal sella. MRI spine showed multilevel vertebral compression fractures. CT chest showed interval growth of mediastinal mass. A 1 mg dexamethasone suppression test failed to suppress ACTH and cortisol, confirming ACTH dependent hypercortisolism. A high dose 8 mg dexamethasone test failed to suppress ACTH and cortisol, a 10 mcg DDAVP stimulation test showed a flat response, with ACTH and cortisol levels remaining comparable before and after DDAVP injection. Dynamic testing therefore consistent with ectopic ACTH dependent hypercortisolism. Gallium-68 DOTA-TATE PET Scan demonstrated uptake in mediastinal mass suggestive of somatostatin receptor positive neuroendocrine tumor. Biopsy specimens processed at our institution showed cells positive for epithelial markers Cytokeratin and PAX8. Sample showed neuroendocrine differentiation with positive staining for Chromogranin A, synaptophysin and CD 117. Findings consistent with neuroendocrine thymic neoplasm. The patient was started on oral ketoconazole to control hypercortisolism. Surgical resection of tumor was planned with intent to cure CS. Ultimately, due to proximal myopathy and multiple vertebral fractures her performance status was too poor for safe tumor resection. Unfortunately, she died of complications related to CS while attempting preoperative rehabilitation. This case illustrates the importance of a timely, systematic evaluation for ACTH source in ACTH dependent hypercortisolism. Delay in CS diagnosis and localizing correct ACTH source led to missing the window of fitness for curative surgery. If ACTH is elevated, the most common source is pituitary neoplasia, however ectopic ACTH production must be ruled out. Dynamic testing including high dose dexamethasone suppression test, CRH and DDAVP stimulation tests should be used for preliminary localization of ACTH production. IPS sampling is invasive with greater potential for complications, as in the case of our patient. Therefore, it is only indicated if there are conflicting results from different dynamic tests and imaging studies. Presentation: No date and time listed

PMON93 Adenoma Size &amp; Inferior Petrosal Sinus Sampling in Cushing's Disease Diagnosis - Smoke &amp; Mirrors?

Abstract Background The current guidelines on Cushing's Disease management recommend surgically resecting adenomas larger than 10 mm in size.1 For smaller adenomas, inferior petrosal sinus sampling (IPSS) is considered the gold standard to distinguish between Cushing's disease and ectopic ACTH production. We report a case where IPSS testing and the size of the adenoma on MRI were misleading in determining the final diagnosis, prompting us to challenge the existing guidelines. Clinical Case A 40-year-old female with a past medical history of hyperlipidemia, obesity (BMI 42) and prediabetes presented with secondary infertility, galactorrhea, headaches, blurred vision and weight gain (30 lbs) over the past year. Physical examination was notable for acanthosis nigricans of the neck and bilateral milky nipple discharge. Prolactin level was elevated to 46.9 ng/ml (n 4.8-23.3 ng/mL). ACTH was elevated to 83.5 pg/mL (n 7.2-63.3 pg/mL) and cortisol to 17.4 ug/dL (n 2.7-10.5 ug/dL). Salivary cortisol was elevated to 0.216 ug/dL (n &amp;lt;0.112 ug/dL), 24-hour urinary cortisol elevated to 60.2 ug (n &amp;lt;45 ug) and on 1 mg dexamethasone suppression testing, morning cortisol was elevated to 7.2 ug/dL (n &amp;lt;1.8 ug/dL). MRI revealed a 6×7×7 mm right sided pituitary mass. Referral to Neurosurgery for resection was made. Neurosurgery recommended bilateral IPSS for pre-operative tumour lateralisation. 10 ug of DDAVP was used to increase test sensitivity. Central to peripheral ACTH ratio was 1: 1. No significant laterality was noted. In the absence of other identifiable sources on CT imaging, endoscopic endonasal surgical resection was pursued. On pathology, the adenoma was immunoreactive for ACTH, confirming Cushing's Disease. Post-operative morning cortisol was 1.3 ug/dL. The patient was started on hydrocortisone 50 mg in the morning and 20 mg in the afternoon with outpatient taper two weeks following discharge to prednisone 10 mg daily. Conclusion Current guidelines recommend surgery for adenomas &amp;gt;10 mm in size, IPSS for adenomas &amp;lt; 6 mm and further diagnostics (IPSS or serum CRH and DDAVP stimulation tests plus whole-body CT) for those 6-9 mm. IPSS is strongly preferred. 1 IPSS is operator dependent and has low efficacy in tumour lateralisation. With the advent of high-resolution CT imaging and emerging data corroborating non-invasive stimulation tests,2 it may be time to shift away from IPSS as a first line test for adenomas irrespective of size. IPSS can present a costly, invasive, oft misleading, and hence superfluous testing strategy; it is high time the medical community re-evaluates its reliance on it.

Corticotroph cell hyperplasia as a rare cause of ACTH-dependent Cushing syndrome

ObjectiveOur aim was to characterise a cohort of patients with Cushing's disease (CD) who did not present pituitary adenoma in magnetic resonance imaging (MRI), needing a catheterisation of the inferior petrosal sinus (CIPS), and to study the pathological findings of the pituitary gland in these subjects after transsphenoidal surgery in order to establish the aetiology of CD. Furthermore, we evaluated possible differences in the features of the diagnosis between hyperplasia and adenoma. Subjects and methodsWe included 16 subjects. 17 CIPS were done. Hormonal parameters were measured using standard methods. A microscopic histochemical study following standard procedures and immunohistochemical analysis was performed. The diagnostic criteria for adenoma and hyperplasia were based on the WHO classification. ResultsOne patient was excluded for presenting an ACTH-producing bronchial neuroendocrine tumour. The 15 subjects with CD have a positive CIPS test indicating hypophyseal ACTH production. After transsphenoidal surgery, 12 patients showed a microadenoma and three (20%) a corticotroph cell hyperplasia. We found four recurrences after the transsphenoidal surgery (26%), with a mean time for recurrence of 105 months. We found that recurrence was more frequent in subjects with hyperplasia, and in those subjects with lower right/left ACTH ratio. ConclusionOur study, which was focused on patients with CD with no pituitary adenoma detected by MRI and a positive CRH test after CIPS, has found that 20% showed corticotroph cell hyperplasia as the cause of CD. Right/left ACTH ratio after CIPS was useful to differentiate adenoma from hyperplasia. This finding may have important prognostic and treatment implications. More studies are necessary to confirm our result.

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: 100years after Minnie G" will provide an update on our current diagnostic workup for the confirmation and differential diagnosis of CS.

Corticotroph cell hyperplasia as a rare cause of ACTH-dependent Cushing syndrome

ObjectiveOur aim was to characterise a cohort of patients with Cushing's disease (CD) who did not present pituitary adenoma in magnetic resonance imaging (MRI), needing a catheterisation of the inferior petrosal sinus (CIPS), and to study the pathological findings of the pituitary gland in these subjects after transsphenoidal surgery in order to establish the aetiology of CD. Furthermore, we evaluated possible differences in the features of the diagnosis between hyperplasia and adenoma. Subjects and methodsWe included 16 subjects. 17 CIPS were done. Hormonal parameters were measured using standard methods. A microscopic histochemical study following standard procedures and immunohistochemical analysis was performed. The diagnostic criteria for adenoma and hyperplasia were based on the WHO classification. ResultsOne patient was excluded for presenting an ACTH-producing bronchial neuroendocrine tumour. The 15 subjects with CD have a positive CIPS test indicating hypophyseal ACTH production. After transsphenoidal surgery, 12 patients showed a microadenoma and three (20%) a corticotroph cell hyperplasia. We found four recurrences after the transsphenoidal surgery (26%), with a mean time for recurrence of 105 months. We found that recurrence was more frequent in subjects with hyperplasia, and in those subjects with lower right/left ACTH ratio. ConclusionOur study, which was focused on patients with CD with no pituitary adenoma detected by MRI and a positive CRH test after CIPS, has found that 20% showed corticotroph cell hyperplasia as the cause of CD. Right/left ACTH ratio after CIPS was useful to differentiate adenoma from hyperplasia. This finding may have important prognostic and treatment implications. More studies are necessary to confirm our result.

Indication to dynamic and invasive testing in Cushing\u2019s disease according to different neuroradiological findings

PurposeDynamic testing represents the mainstay in the differential diagnosis of ACTH-dependent Cushing’s syndrome. However, in case of undetectable or detectable lesion < 6 mm on MRI, bilateral inferior petrosal sinus sampling (BIPSS) is suggested by current guidelines. Aim of this study was to analyze the performance of CRH, desmopressin and high-dose dexamethasone suppression test (HDDST) in the differential diagnosis of ACTH-dependent Cushing’s syndrome as well as the impact of invasive and noninvasive tests on surgical outcome in patients affected by Cushing’s disease (CD).MethodsRetrospective analysis on 148 patients with CD and 26 patients with ectopic ACTH syndrome.ResultsAmong CD patients, negative MRI/lesion < 6 mm was detected in 97 patients (Group A); 29 had a 6–10 mm lesion (Group B) and 22 a macroadenoma (Group C). A positive response to CRH test, HDSST and desmopressin test was recorded in 89.4%, 91·4% and 70.1% of cases, respectively. Concordant positive response to both CRH/HDDST and CRH/desmopressin tests showed a positive predictive value of 100% for the diagnosis of CD. Among Group A patients with concordant CRH test and HDDST, no difference in surgical outcome was found between patients who performed BIPSS and those who did not (66.6% vs 70.4%, p = 0.78).ConclusionsCRH, desmopressin test and HDDST have high accuracy in the differential diagnosis of ACTH-dependent CS. In patients with microadenoma < 6 mm or non-visible lesion, a concordant positive response to noninvasive tests seems sufficient to diagnose CD, irrespective of MRI finding. In these patients, BIPSS should be reserved to discordant tests.

A new model for the HPA axis explains dysregulation of stress hormones on the timescale of weeks.

Stress activates a complex network of hormones known as the hypothalamic–pituitary–adrenal (HPA) axis. The HPA axis is dysregulated in chronic stress and psychiatric disorders, but the origin of this dysregulation is unclear and cannot be explained by current HPA models. To address this, we developed a mathematical model for the HPA axis that incorporates changes in the total functional mass of the HPA hormone‐secreting glands. The mass changes are caused by HPA hormones which act as growth factors for the glands in the axis. We find that the HPA axis shows the property of dynamical compensation, where gland masses adjust over weeks to buffer variation in physiological parameters. These mass changes explain the experimental findings on dysregulation of cortisol and ACTH dynamics in alcoholism, anorexia, and postpartum. Dysregulation occurs for a wide range of parameters and is exacerbated by impaired glucocorticoid receptor (GR) feedback, providing an explanation for the implication of GR in mood disorders. These findings suggest that gland‐mass dynamics may play an important role in the pathophysiology of stress‐related disorders.

SUN-917 Aggressive De Novo MEN1 Variant in a Child with Metastatic Pancreatic Acth and Crh Co-Secreting Neuroendocrine Tumor: Diagnosis and 10-Year Follow Up

Background:In Multiple Endocrine Neoplasia type 1 (MEN1) only about 2% of pituitary adenomas are ACTH-secreting. Cushing Syndrome due to ectopic ACTH or CRH secretion from neuroendocrine tumors (NETs), carcinoid tumors, or pheochromocytomas is very rare, though patients with MEN1 are at increased risk for these three types of tumors, as well as autonomous adrenal secretion of cortisol. The 10-year follow up of a previously-reported case of a child with MEN1 and metastatic pancreatic ACTH/CRH-secreting NET is presented.Clinical Case:A previously-reported (J Clin Endocrinol Metab, 2015) now 21 yo female presented to the National Institutes of Health (NIH) at 11 yo with persistent hypercortisolemia despite transsphenoidal surgery for suspected Cushing Disease. However, the resected tissue revealed pituitary hyperplasia, and she remained hypercortisolemic. A CRH test was consistent with an ectopic source, and abdominal CT, PET scan, and Octreotide scan revealed a mass in the pancreatic tail. The patient underwent partial pancreatectomy at 11 yo with the resected tissue staining positive for ACTH and CRH. However, she remained hypercortisolemic, so bilateral adrenalectomy was performed. At 12 yo metastases were found, so Octreotide therapy was initiated. She continued to have elevated ACTH levels > 1000 pg/mL (5-46).Additionally, a pituitary adenoma was noted at 12 yo, which has since increased in size. The patient also developed mild primary hyperparathyroidism, first noted at 19 yo. Sequencing of MEN1 for the patient and her parents revealed a de novo heterozygous c.1546dupC variant, consistent with sporadic MEN1. The patient also had a chromosome 8p23.2 duplication that was present in unaffected relatives.Conclusion:While 2% of patients with MEN1 may develop Cushing Syndrome due to an ACTH-secreting pituitary adenoma, it is also important to consider ectopic secretion of ACTH/CRH from MEN1-associated NETs, carcinoid tumors, or pheochromocytomas, as well as autonomous adrenal secretion of cortisol. Given the early age and severe presentation of MEN1 features in this patient, the c.1546dupC heterozygous variant of MEN1, which has been previously reported in multiple other cases of MEN1, may represent a higher-risk causative variant of MEN1. Alternatively, expression of this variant may have been affected by the concurrent presence of an otherwise apparently benign chromosomal variant.

SAT-244 Inflammatory Rathke Cleft Cyst Caused Hypothalamic Panhypopituitarism

Background: Hypothalamic panhypopituitarism was a rare disease which was caused by brain tumors such as Rathke cyst, germinoma, malignant lymphoma and craniopharyngioma, and vascular accidents such as thrombosis and hemorrhage. We have found a rare case of hypothalamic panhypopituitarism occurred by the inflammation of Rathke cyst. Case presentation: A 77-year-old woman was admitted to our hospital because of severe headache, nausea, vomiting and fever. Hyponatremia (Na 131 meq/L) and increased CRP level (0.20 mg/dl) and no finding of gastroenterological examination and abdominal CT scanning were observed. Endocrinological examination revealed low levels of anterior pituitary hormones such as GH, LH, FSH and ACTH and increased PRL levels and low level of serum cortisol. Simultaneous CRH, TRH and LH-RH stimulations tests indicated low responses of TSH, LH, FSH and PRL and hyperesponse of ACTH (from 2.4 to 251 pg/ml). Radiological examination by enhanced MRI revealed high intensity of T2-weighted images and low and partial high intensities of T1-weighted images in swelling of pituitary gland and vanishment of high intensity of posterior lobe in T2-weighted images suggesting that the inflammatory wall of Rathke cyst. We searched previous data of ACTH and cortisol levels which showed normal level of ACTH (55.2 pg/ml) and cortisol 18.8 μ;g/dl) when headache and nausea arouse on 50 days before. Based on above results patient was diagnosed as hypothalamic hypopituitarism due to inflammatory Rathke cyst. Therefore, patient was treated with hormone replacement therapy by 20 mg of hydrocortisone. After these treatment, polyuria, urinary low osmotic pressure and hypernatremia appeared due to partial diabetes insipidus caused by the impairment of posterior lobe in pituitary gland, and diagnosed by the examination of vasopressin test. This patient was also treated by the oral desmopressin acetate hydrate (60 μ;g/day), and has been well-tolerated in the outpatient clinic. Conclusion: These results suggested that inflammatory Rathke cyst with inflammatory changes in hypothlamo-pituitary system raised a rare case of hypothalamic panhypopituitarism.Reference: Nishioka H. et al.: Clin Endocrinology (Oxf) 2006:64:184–188