ACTH Stimulation Test Research Articles

Bilateral adrenal hemorrhage in a postpartum woman with multiple thromboemboli: A case report

BackgroundBilateral adrenal hemorrhage is a rare but often a fatal cause of primary adrenal insufficiency that can result in adrenal crisis if not identified and managed appropriately.Case presentationWe present a case of a 27-year-old Caucasian female who was admitted to the hospital 17 days postpartum with pleuritic chest and flank pain, shortness of breath and nausea. Computed tomography imaging confirmed multiple thromboemboli including pulmonary emboli and noted bilateral bulky adrenal glands. She was managed for infection and pulmonary emboli; however, she complained of persistent headaches, nausea, and vomiting despite appropriate management. Radiology re-review found the computed tomography imaging was consistent with bilateral adrenal hemorrhage in hindsight. Subsequent endocrine evaluation with hypothalamic–pituitary–adrenal axis interrogation and adrenocorticotropic hormone (Synacthen) stimulation testing confirmed resultant primary adrenal insufficiency. She required urgent intravenous hydrocortisone and was subsequently discharged on oral adrenal replacement therapy and anticoagulation.ConclusionsDelay in identification and treatment of adrenal insufficiency can lead to catastrophic outcomes. This case highlights the challenge of diagnosing bilateral adrenal hemorrhage and resultant adrenal insufficiency as patients may not present with the classic risk factors, signs, symptoms, and electrolyte derangements.

Can salivary cortisol be used in diagnosing adrenal insufficiency during the acute and subacute phases of traumatic brain injury?

The diagnosis of adrenal insufficiency (AI) related to traumatic brain injury (TBI) remains a challenge. We investigated the basal and low-dose adrenocorticotropic hormone (ACTH)-stimulated serum cortisol and salivary cortisol (SaC) levels and the diagnostic utility of SaC levels during 28 days following TBI. Blood samples were collected for basal levels [sequentially from day 1 (D1) to D7 and on D28)] and for peak serum cortisol and SaC responses to the low-dose ACTH stimulation test (on D1, D7, and D28). After the patient enrollment period was completed, patients were retrospectively categorized as AI or AS (adrenal sufficiency) for each day separately, based on a basal serum cortisol cut-off level of 11 µg/dL, and data analysis was performed between the groups. Thirty-seven patients and 40 healthy controls were included. Median basal serum cortisol levels were higher in patients on D1 but were similar on other days. Median basal SaC levels were higher in patients on D1 and D2 but were similar on other days. Median peak serum cortisol and SaC levels were similar on D1 but were lower in patients on D7 and D28. Median basal SaC levels were higher in the AS group than in the AI group on all days. When evaluating AI during the course of TBI, the cut-off for basal SaC levels is 0.5-0.6 µg/dL throughout the first week, except for 1.38 µg/dL on D2. SaC levels may serve as a surrogate marker for accurately reflecting circulating glucocorticoid activity.

ACTH stimulation and oral salt loading tests detect biochemical outcome early after primary aldosteronism surgery.

In primary aldosteronism (PA), the biochemical outcomes of the Primary Aldosteronism Surgical Outcome study are used to assess aldosterone hypersecretion 6-12 months after surgery. However, few studies have investigated whether the outcomes can be predicted in the early postoperative period. In this retrospective study, we evaluated whether the adrenocorticotropin stimulation test (AST) and oral salt loading test (OST) performed immediately after surgery could predict biochemical outcomes 1 year after surgery. We assessed 268 patients with PA who underwent adrenalectomy at our hospital between 2008 and 2020, underwent AST and OST within 15 days of surgery, and were assessed for biochemical outcomes 1 year after surgery. Patients were divided into two groups: biochemical complete success (B-com; n = 219) and incomplete success (B-inc; n = 49). Patients were divided into clinical complete and partial success and absent success groups. The relationships between various AST and OST values and outcomes were analyzed. The B-inc group had significantly higher plasma aldosterone concentration (PAC) and PAC/serum cortisol ratio (PAC/Cort) at baseline and after ACTH loading in AST and 24-hour urine aldosterone in OST than the B-com group. PAC/Cort at 30 min after ACTH loading (area under the curve (AUC) = 0.76) and 24-hour urine aldosterone (AUC = 0.77) were relatively superior predictors of the outcome. Parameters after ACTH loading were better predictors of biochemical and clinical outcomes than baseline. AST and OST immediately after surgery can predict biochemical and clinical outcomes 1 year after surgery in patients with PA.

7560 Using a Single Pre-test Cortisol Level To Reduce The Need For Dynamic Testing For Adrenal Insufficiency In A Southeast Asian Population

Abstract Disclosure: V. Ramadoss: None. L. Tan: None. A.E. Teo: None. K. Lazarus: None. K. Meeran: None. D. Deepak: None. L. Ong: None. C. Khoo: None. P. Eng: None. Introduction: The Short Synacthen Test (SST) is widely used in clinical practice to assess Adrenal Insufficiency (AI). Despite its relative ease of administration, Synacthen use is limited by its availability and its administration demands supervision by experienced staff, resulting in increased testing cost. A single measurement of serum cortisol has been shown to predict AI, but the suggested threshold varies according to the patient cohort studied, assay variation and the prevalence of the condition relative to the size of population tested. This study aims to (a) identify a threshold cortisol level to screen for AI in a South-East Asian population and (b) to determine the utility of a stimulated 60-minute cortisol level in the diagnosis of AI. Methods: This is a retrospective analysis of SSTs (250 micrograms) performed in our institution between 28th February 2022 to 28th February 2023. Serum cortisol in our institution was measured by Abbott Alinity analysers. We defined a normal response as a stimulated cortisol value of ≥ 420nmol/L at either 30-minutes, 60-minutes, or at both time points. Logistic regression analysis was performed to predict normal responses based on baseline cortisol level. Results: Median cortisol level at baseline, 30-minutes, and 60-minutes after Synacthen stimulation were 254 (IQR 191-320) nmol/L, 499 (IQR 415 -585) nmol/L, 574 (IQR 476 -662) nmol/L respectively. A total of 785 SSTs were performed, out of which 83.1% were normal and 16.9% were abnormal. Of the 785 SSTs, 55 (7.0%) would have failed if only the 30-minute cortisol was assessed without the 60-minute value, whereas 10 (1.4%) would have failed if only the 60-minute cortisol was assessed without the 30-minutes value. An early morning basal cortisol (0800am to 1200pm) cut-off of <300nmol/L identified subnormal cortisol with 95.0% sensitivity and an afternoon cortisol (1200pm to 1700) of < 312nmol/L achieved 95.2% sensitivity. A basal cortisol level of < 100nmol/L will confirm AI with 97.3% specificity. Using a basal cortisol level of ≥ 300nmol/L, 94.8% of individuals go on to pass the SST. Use of this basal cortisol value would avoid 252 (32.1%) SSTs. Conclusion: A single measurement of basal cortisol of ≥ 300nmol/L has the potential to exclude AI with 95% sensitivity on Abbott Alinity platform in our cohort of patients. Using a threshold cortisol level of 300nmol/L, at least 32% of the SSTs could be avoided. This would have improved patients experience with cost savings implications. Furthermore, a stimulated 60-minute cortisol level identifies 55 (7%) of individuals who would otherwise be misclassified as AI, thereby avoiding unnecessary long-term glucocorticoid replacement. Presentation: 6/1/2024

8319 Pituitary Apoplexy Leads to the Spontaneous Resolution of Hypercortisolism Secondary to Cushing Disease: A Clinical Case

Abstract Disclosure: N. Sweis: None. J. Sanchez Perez: None. M. Fariduddin: None. R.M. Sargis: None. D.J. Toft: None. S. Reutrakul: None. Background: Pituitary apoplexy is a potentially fatal condition involving the infarction or hemorrhage of the pituitary gland. Rarely, it can occur in the setting of an ACTH-secreting pituitary adenoma. Clinical Case: A 27-year-old female with a past medical history of obesity, spontaneous miscarriages, and amenorrhea presented to the ER with an acute onset frontal headache of throbbing quality, associated with nausea and vomiting. The headache began two days prior, rapidly intensified, and did not improve with oral acetaminophen. CT of the head revealed an enlarged pituitary gland, while neurovascular imaging showed no abnormalities. Her neurologic examination was normal. She denied visual changes, photophobia, neck rigidity, fevers, chills, or recent infections. Furthermore, she endorsed a weight gain of about 40 pounds over the past year despite no change in dietary habits. This was accompanied by amenorrhea, hair thinning, itchy comedonal acne, hirsutism, and a loss of libido. Her physical examination was remarkable for the presence of cushingoid features including violaceous abdominal striae, facial acne, moon facies, a dorsal fat pad, and acanthosis nigricans around the neck and axillae. Pituitary MRI with and without contrast showed an enlarged sellar and suprasellar macroadenoma measuring approximately 2.1x1.4x1.2 cm abutting the optic chiasm. The visualized lesion contained hemorrhagic products, suggesting pituitary apoplexy. Biochemical testing on admission included a low morning plasma cortisol of 6.5 ug/dL (ref. range: 6.7-22.6 ug/dL), a 24-hour urine free cortisol of 12.0 (<=45.0 ug/24 hour), and an elevated ACTH of 145.0 pg/mL (7.2 - 63.3 pg/mL). A1c was 5.8% (<5.7%). Serum levels of prolactin, IGF1, GH, LH, FSH, TSH, Free T4, estradiol, total and bioavailable testosterone were within normal limits. She was evaluated with an ACTH stimulation test, which showed a morning cortisol level of 1.2 ug/dL at baseline, lower from prior. Cortisol levels were adequately increased at 19.6 ug/dL and 22.6 ug/dL, 30 and 60 minutes after the administration of Cosyntropin 250 mcg, respectively (>=18 ug/dL after 30-60 mins). The level of ACTH at the time was also decreased to 76.6 pg/mL. The patient was therefore started on steroid replacement therapy with hydrocortisone and later underwent transsphenoidal resection of the pituitary mass without complications. Histopathological examination of the resected mass showed pituitary adenoma cells with diffuse weak to moderate ACTH staining, most consistent with a sparsely granulated corticotroph pituitary adenoma. Conclusion: We report an interesting case of Cushing disease that spontaneously resolved after pituitary apoplexy. Our case underlines the importance of close monitoring of such patients who may rapidly undergo a period of adrenal insufficiency after hypercortisolism. Presentation: 6/3/2024

5132 Unraveling the Enigma: A COVID-19 Triggered Revelation of Adult Idiopathic ACTH Deficiency

Abstract Disclosure: K.A. Arao: None. A.E. Gadbois: None. Introduction: Adult idiopathic ACTH deficiency (AIAD) is a rare and potentially life-threatening condition that is frequently misdiagnosed or even missed. We present a case of AIAD in a patient who exhibited altered mental status alongside a COVID-19 infection and was fortunately diagnosed after responding to empiric treatment with oral steroids for another condition. Case Presentation: A 76-year-old man was admitted to the hospital for bilateral leg weakness. His hospital stay was complicated by the development of febrile episodes and delirium. He tested positive for COVID-19, and the rest of infectious work-up yielded negative results. He then received a course of remdesivir. In the evaluation of his delirium, a CT scan of the brain, MRI of the brain, and lumbar puncture with CSF analysis were done, all of which were unremarkable. Initially, the delirium was attributed solely to COVID-19 infection. After consultation with neurology and rheumatology, the patient received empiric treatment with prednisone 5 mg twice daily for possible polymyalgia rheumatica as a cause of his bilateral leg weakness. His mental status significantly improved following steroid administration. With the improvement in symptoms, an AM cortisol test was added on his morning blood tests, revealing a cortisol level of 2.56 mcg/dL with an albumin level of 2.3 g/dL, raising concerns for adrenal insufficiency. An outpatient endocrinology evaluation recommended transitioning from prednisone to physiologic twice-daily dosing of hydrocortisone. An ACTH stimulation test was performed, which peaked at an AM cortisol of 6.1 mcg/dL, with a baseline ACTH level of 4.1 pg/mL. A review of the recent brain MRI showed no pituitary pathology. Other pituitary hormones were normal, and he was eventually diagnosed with AIAD. He was subsequently maintained on physiologic dosing of hydrocortisone, resulting in clinical stability. Discussion: AIAD is characterized by secondary adrenal insufficiency, normal production of other pituitary hormones, and the absence of structural pituitary pathology. The etiology of AIAD remains unknown, with most cases attributed to an autoimmune process. AIAD can have diverse clinical manifestations and may only become more apparent with triggers like infections or illnesses. As in our case, the COVID-19 infection likely unmasked the underlying AIAD, presenting with altered mental status. Identifying AIAD can be challenging, leading to high rates of misdiagnosis and clinical omission. Physicians should consider AIAD when dealing with unexplained altered mental status, as the administration of a simple treatment with steroids can be life-changing. Presentation: 6/3/2024

6400 An Unusual Presentation of Silent Corticotroph Pituitary Macroadenoma

Abstract Disclosure: N. Mon: None. V. Lohano: None. B. Williams: None. N. Lehman: None. R. Kulkarni: None. S.L. Mokshagundam: None. Silent Corticotroph Pituitary Adenomas (SCA) are a rare group of nonfunctioning pituitary adenomas (NFA) comprising 3-6% of all pituitary adenomas and up to 20% of corticotroph adenomas. SCA are biologically and clinically distinct from Cushing disease and NFA. SCA present with headache, visual field impairment, hypopituitarism, and pituitary apoplexy. We present a case of SCA with the initial presentation of syncope with undetectable ACTH and very low AM cortisol level.A 67 year-old-female was incidentally found to have a pituitary macroadenoma in MRI brain for syncope work up in 2017. MRI reported 1.4 x 1.2 x 1.3 cm sellar mass with suprasellar extension, minimal mass effect on the optic chiasm and no cavernous sinus invasion. Initial labs showed ACTH <5 (7.2-63.3 pg/mL), AM cortisol 0.8 (6-28ug/dl), Prolactin 101.1 (3.3-27 ng/mL), TSH 0.08 (0.34-5.60 uIU/mL), Free T4 0.6 (0.58-1.64 ng/dL), FSH 1.7 (2-5 mIU/mL), LH <0.2 (1-13 mIU/mL), IGF-1 33 ( 41-279 ng/mL). ACTH stimulation test: cortisol 0.5 ug/dl at baseline, 5.8 ug/dl at 60min. She was diagnosed with panhypopituitarism and hyperprolactinemia due to stalk effect. Hydrocortisone and Levothyroxine (LT4) were started. She underwent pituitary macroadenoma resection for optic chiasm decompression in 2017. Pathology reported pituitary neuroendocrine tumor (pitNET), but no immunostaining was done at that time. Follow up MRI in 2019 showed residual pituitary tumor. In 2023, she endorsed headaches, mood changes, fatigue and weight gain. Physical exam was unremarkable except BMI 34.75. Prolactin, Free T4, IGF-1 were normal. MRI in 2023 revealed recurrent and enlarging pituitary adenoma (1.9 x 1.4 x 1.6 cm) with suprasellar extension, abutting the optic chiasm, and left cavernous sinus invasion with internal carotid artery encasement. She underwent revision transsphenoidal resection of pituitary tumor to decompress the optic chiasm with plan for subsequent focused radiation to the cavernous sinus portion. Postoperative period was uneventful and hydrocortisone and LT4 were continued on discharge. Final pathology reported silent corticotroph lineage pitNET with low Ki67, immunostaining positive for TPIT, CAM5.2, and negative for ACTH. ACTH-negative SCA are a rare subtype and more likely to have lower ACTH levels, and multiple microcysts on MRI than ACTH-positive SCA. New WHO classification of pitNET highlights the histological typing and subtyping based on immunostaining of pituitary lineage transcription factors as the cornerstone for accurate classification. SCA are more biologically aggressive tumors with a high propensity of recurrence and resistance to conventional treatment. TPIT and ACTH immunostaining significantly improved the diagnosis of SCA and thereby close clinical follow up for early recognition and management of SCA recurrence. Absence of serum markers of recurrence makes this challenging. Presentation: 6/1/2024

7247 Adrenal Insufficiency In Advanced Cirrhosis: A ‘Shocky’ Clinical Dilemma

Abstract Disclosure: L. Aboishava: None. A. Pareek: None. A. Mertens: None. A. Erokhin: None. Background: In patients with advanced cirrhosis, profound hypoproteinemia can complicate the laboratory assessment of the hypothalamic-pituitary-adrenal axis, but a clinical phenotype of persistent hypotension and suboptimal cortisol response to ACTH stimulation raises the question of whether adrenal insufficiency could also be a contributing factor. Clinical Case: A 65-year-old man with a history of cirrhosis complicated by esophageal varices, ascites, encephalopathy and hepatorenal syndrome was admitted to the ICU with worsening fatigue, profound hypotension, and respiratory arrest. He was started on pressors, antibiotics and was also intubated for a short time. A broad workup was negative for cardiac or infectious causes of shock and showed decreased total protein and albumin (1.6 g/dl (3.5-5.2), with normal serum sodium and potassium. The patient had no previous history of adrenal disease or corticosteroid use. Workup for adrenal insufficiency was initiated and showed decreased morning blood serum cortisol (10.6 ug/dl (2.5-19.5)) and ACTH (<5.0 pg/ml (7.2-63)), as well as suboptimal cortisol response on ACTH stimulation testing (12.5 ug/dl initially, 16.7 ug/dl after stimulation). Head CT on admission was negative for intracranial pathology, and lab results showed normal TSH and mildly increased prolactin of 36.2 ng/ml (4.0-15.0). Pt was started on IV hydrocortisone 50 mg TID. Glucocorticoid therapy didn’t improve his state significantly but was continued with a gradual tapering down of the dose. After intense treatment in the ICU the patient’s state was stabilized. Unfortunately, an endoscopy performed for worsening anemia and blood in stools showed gastric cancer. The patient was transferred to comfort care after a discussion of goals of treatment and died within the next 24 hours. Conclusion: The nature of decreased cortisol levels in patients with cirrhosis is most likely multifactorial, due to impaired hepatic synthetic function, dysregulation of hormone-binding protein balance, abnormal ACTH secretion, and other factors. Impaired corticosteroid-binding globulin synthesis might affect the ratio of globulin-bound and free hormone fractions and alter the accuracy of cortisol assays. Whether adrenal insufficiency is truly one of the complications of advanced cirrhosis contributing to persistent hypotension, or a mere laboratory finding is difficult to answer. It is also yet to be determined whether patients with advanced cirrhosis might benefit from screening and treatment of adrenal insufficiency in circumstances of persistent hypotension, and studies are needed to decide on optimal diagnostic tests to recognize the disease and develop treatment algorithms. Presentation: 6/3/2024

7452 A Diagnostically Challenging Case of Hyperandrogenism in Postmenopausal Woman

Abstract Disclosure: M.S. Hossain: None. S. Hossain: None. B. Gautam: None. H. liao: None. S.C. Kumar: None. D.S. Rosenthal: None. Background: The diagnosis of new-onset severe hyperandrogenism in postmenopausal women is rarely encountered, posing a unique challenge for clinicians. Ovarian hyperthecosis and androgen-secreting tumors are the usual suspects in post menopause. In our case ovarian hyperthecosis is the primary consideration but elevated 17-OH Progesterone (17-OHP) introduces the potential co-existence of Non classical congenial adrenal hyperplasia (NCCAH) or rare instances of Sertoli-Leydig Cell Tumor (SLCT). Case Presentation: A 70 years old female, with no past medical history, referred to the Endocrinology clinic for significantly elevated testosterone level. She reported excessive hair growth in various areas of her body since 2022, which required shaving almost every day. She also reported male pattern hair loss and weight loss of 15 lbs over the last three months. She denied headache, vision changes, deepening of voice, history of fertility problems and use of exogenous testosterone. Her vital sign were normal. On examination, she had clitoromegaly, terminal hair growth on her upper lip and chin, breast atrophy, male pattern baldness, but no cushingoid or acromegaly features. Blood tests showed significantly elevated total testosterone: 1422 ng/dl (2-45); free testosterone: 147.9 pg/ml (0.2-3.7) and Estradiol: 64 pg/ml (Postmenopausal <31) with low LH: 7.6 mIU/ml (Postmenopausal 10.0-54.7) and FSH: 22.2 mIU/mL (Postmenopausal 23-116). Her serum ACTH, DHEA Sulfate, 11-deoxycortisol, 17 OH pregnenolone, TSH, Free T4, prolactin, IGF-1 were normal while her 17-OHP: 396 ng/dl (<45 ng/dl) was significantly elevated. An ACTH stimulation test showed 17-OHP level of 734 ng/dl at 30 minutes and 901 ng/dl at 1 hour. Pelvic ultrasonography: right ovary of 2.3 x 1.6 x 1.9 cm and the left ovary of 3.1 x 1.8 x 3.0 cm. MRI showed normal adrenal glands but a prominent left ovary. Patient was referred to the Obstetrics department to undergo bilateral oophorectomy for the definitive diagnosis and treatment. Discussion: The current ACTH stimulation test for non-classical congenital adrenal hyperplasia is validated for premenopausal women but lacks standardization in post-menopausal state. In our case, distinguishing the source of elevated 17-OHP between adrenal (NCCAH) and ovarian (SLCT) was difficult. Unexpected asymmetry in ovarian size observed in our case further complicates the scenario, contrasting with the typical symmetrical enlargement seen in ovarian hyperthecosis. Pending surgical pathology will further guide the management. This case highlights the complexity of diagnosing hyperandrogenism in postmenopausal women, emphasizing the significance of thoroughly exploring differential diagnoses and meticulously analyzing laboratory results. Presentation: 6/2/2024

7658 A Case of Recurrent Cardiac Tamponade as Initial Presentation of Primary Adrenal Insufficiency

Abstract Disclosure: A. Farooq: None. A. Ghumatkar: None. J. Snitzer: None. Introduction:Cardiac tamponade, a life-threatening emergency, can be associated with primary adrenal insufficiency (Addison Disease), and accurate diagnosis requires a high degree of clinical suspicion in patients with uncertain etiology and nonspecific signs and symptoms. Case Presentation:A 58-year-old female with a history of Hashimoto thyroiditis was evaluated in the hospital for two episodes of cardiac tamponade requiring emergent pericardiocentesis within one month. The patient had been experiencing symptoms of fatigue, nausea, lightheadedness, dizziness, hiccups, and tanned skin for the past year. She also had a recent flu-like illness with nausea and vomiting four months before her current presentation. Her vitals were notable for hypotension during these episodes. Her lab work showed hyponatremia (128 mEq/L, reference range: 136-145 mEq/L) with normal potassium and glucose levels. Her thyroid function tests were within normal limits on her home levothyroxine dosage (TSH 4.588 IU/ml, reference range: 0.5-8.9 IU/ml). An ACTH stimulation test was performed based on the patient's clinical presentation, consistent with adrenal insufficiency. Her baseline cortisol level was 5.9 mcg/dL (reference range: 6.7-22 mcg/dL), a post-ACTH stimulation level of 6.7 mcg/dL after 30 minutes, and 6.0 mcg/dL after 60 minutes. Her 21 alpha-hydroxylase antibody titer was also positive for Addison Disease (231U/mL, reference range <1 IU/mL). A CT scan of the abdomen with intravenous contrast was done, which revealed no abnormality of the adrenal glands. She was treated with stress doses of hydrocortisone during hospitalization and discharged with maintenance dosage and follow-up with endocrinology. She had another episode of acute adrenal crisis about a month later but had no pericardial effusion this time and responded well to the treatment with stress doses of steroids. She has remained healthy at 14 years of follow-up. Conclusion: This case emphasizes the need to consider adrenal insufficiency in the evaluation of cardiac tamponade or pericardial effusions, especially in patients with existing autoimmune glandular disorders. This patient may have autoimmune polyglandular syndrome type 2 (APS-2), which is a cluster of two or more endocrine glandular disorders primarily diagnosed in adulthood and predominant in females. The risk of adrenal crisis is more than twofold in Addison disease due to APS-2. Lastly, this case highlights that hiccups can be related to adrenal insufficiency, with pathophysiology possibly involving diaphragmatic irritation due to adrenal inflammation that resolves with treatment. Presentation: 6/3/2024

12271 Differential Impacts Of Body Composition Indices On Cortisol Response And Hpa Axis Activity

Abstract Disclosure: S.G. Gonsalves: None. A. Ross: None. M.E. Steele: None. L.N. Saligan: None. Aim: The continued interest in the influence of muscle mass and fat distribution on stress stems from its implications on preventative healthcare. Fat mass index (FMI) and fat-free mass index (FFMI) were proposed as valuable indicators of body composition beyond body mass index (BMI). This study investigated correlations of FMI and FFMI with inflammatory stress markers, hypothesizing that these body composition indices identify inflammatory stress markers more distinctly than BMI. Methods: Skeletal muscle mass was assessed by Dual-Energy X-ray Absorptiometry, HPA axis response through an adrenocorticotropic hormone (ACTH) stimulation test, and markers of inflammation and stress response (e.g., dehydroepiandrosterone, DHEA) from peripheral blood of 104 healthy individuals aged 18-71 years, 52% female, with a mean BMI of 26.3 (+4.83). Perceived stress and fatigue were captured using patient-reported outcome questionnaires before the HPA procedure. Results: ACTH correlated with FFMI at baseline (ρ=0.299, p=0.009) and 60 minutes (ρ=0.254, p=0.041). Cortisol correlated with FFMI at 15 (ρ=–0.248, p≤0.025), 30 (ρ=–0.284, p≤0.010), and 60 minutes (ρ=–0.364, p≤0.001), and with BMI at 15 (ρ=–0.228, p=0.041). FMI and BMI did not correlate with ACTH and FMI with cortisol at any timepoint. With repeated measures ANOVA, FFMI at 50th percentile had large effect on cortisol (p=0.005, partial eta=0.094) at each timepoint, higher for the under lean than those with higher FFMI, compared to BMI at the same percentile (p=0.037, partial eta=0.054). None of the indices reached significance with ACTH. FMI correlated with Erythrocyte Sedimentation Rate (ESR) (ρ=0.521), C-reactive protein (CRP, ρ=0.493, both at p≤0.001), DHEA (ρ=0.252, p=0.030), and epinephrine (ρ=–0.246, p=0.045). FFMI was not correlated with ESR and CRP. BMI correlated only with albumin (ρ = –0.412, p ≤ 0.001 and CRP (ρ=0.342, p≤0.003). Discussion: The higher correlations of inflammatory stress markers with FMI and FFMI, as compared to BMI, supports our study hypothesis. These results hint that these body composition indices may detect subtle stress-related inflammatory changes than BMI. Future research should clarify underlying mechanisms driving these associations and explore the impact of targeted interventions on these indices and subsequent changes to inflammation and stress. Presentation: 6/1/2024

8528 An Unusual Case Of Adrenal Hemorrhage As An Initial Manifestation Of Castleman Disease In A 29 yo Male With Unsuspected Late-Onset Congenital Adrenal Hyperplasia

Abstract Disclosure: L.M. Martel: None. F. Mercier: None. S. Parisien-La Salle: None. A. Lacroix: None. A. Liberman: None. N. Bettache: None. H. Olney: None. I. Bourdeau: None. Background: Castleman disease is a lymphoproliferative disorder with no clear etiology. We report the case of a 29 yo man presenting with an adrenal hemorrhage as initial manifestation of Castleman disease and unsuspected late-onset congenital adrenal hyperplasia. Clinical case: A 29-year-old male with no significant past medical history except for unilateral orchiectomy at 1 year-old for a possible testicular mass was referred to our adrenal clinic for a 6,2x7,5 cm left adrenal mass showing at CT scan necrosis and an hemorrhagic component (HU52). The patient presented initially with acute left abdominal pain. The adrenal mass showed at peripheral high uptake at PET-FDG (SUVmax 5,3) with no central uptake. His physical exam was unremarkable except for obesity. The hormonal work-up for the adrenal mass revealed normal metanephrines, and normal 1mg-dexamethasone suppression test with morning cortisol of 18 nmol/L (N<50). Further hormonal investigations based on the high adrenal mass uptake and possible adrenocortical carcinoma included: 17-OH Progesterone: 7.7 nmol/L (N:1.1-7.0), Androstenedione: 14.1 nmol/L (N: 1.5-9.0), Testosterone: 11.3 nmol/L (N: 9.0-28.3) and DHEAS: 3.6 umol/L (2.3-18.7). The ACTH levels were increased at 21.2 pmol/L (N:2-11) with morning cortisol of 220 nmol/L. During the consultation, the patient reported a pleuritic chest pain and underwent an urgent CT pulmonary angiography showing a pulmonary embolism with lung infarction in addition to mediastinal lymphadenopathy (biopsy negative) and a mass in his thymus. He underwent thymectomy and the pathology report described Castleman disease (hyaline vascular type). Taking into account the increased level of 17-OH progesterone, we performed an ACTH stimulation test (250 mcg) that showed an increase of cortisol levels from 333nmol/L to 874nmol/L at 60 minutes and of 17OH Progesterone levels from 5.2nmol/L to 44.2nmo/L excluding adrenal insufficiency, but confirming the diagnosis of late-onset congenital adrenal hyperplasia. Genetic analyses: After written consent, the patient underwent genetic analysis of the CYP21A2 gene by direct sequencing and MLPA. The analyses revealed a heterozygous pathogenic variant in the CYP21A2 gene (c.293-13A/C>G). No other genetic variant was identified in the gene. Follow-up: Subsequent adrenal MRIs showed decreasing size of the left adrenal mass; 3 cm at 3 months, 2 cm at 6 months and no residual mass was seen at 9 months supporting the diagnosis of adrenal hemorrhage. Conclusion: To our knowledge, we report a first case of Castleman disease presenting with adrenal hemorrhage as initial symptom with the association of late-onset congenital adrenal hyperplasia. The possible link between these diseases remains to be explored. Presentation: 6/3/2024

6712 Intractable Hypoglycemia: A Clue to Tumor Diagnosis

Abstract Disclosure: N. Kharkongor Chengappa: None. E.I. Krug: None. Background: Non-Islet Cell Tumor Hypoglycemia (NICTH) known as Doege-Potter syndrome, is a rare paraneoplastic syndrome of hypo-insulinemic hypoglycemia caused by excessive production of partially processed IGF-II from a solitary fibrous tumor (SFT).We present a case of a patient admitted with intractable hypoglycemia leading to the diagnosis and treatment of a large pelvic SFT. Clinical Case: A 59-year-old male with type 2 Diabetes Mellitus on metformin mono therapy, was admitted after he collapsed at work and was found to have blood glucose (BG) of 22 mg/dl. He was previously in his usual state of health except for an increase in his shoe size over the past year. Physical examination revealed coarse thick skin, large coarse bullous nose, enlarged fingers and a non-tender, firm abdomen with no obvious organomegaly. Laboratory results including CBC, CMP and thyroid function were normal. ACTH stimulation test revealed normal adrenal function. Hypoglycemic drug screen and insulin antibodies were negative. During a hypoglycemic event (BG of 45mg/dl) he had C-peptide level < 0.1ng/ml, beta-hydroxybutyrate levels of <0.05 and insulin level <0.4uIU/ml, indicating non-insulin mediated hypoglycemia. IGF-I and IGF-II levels were ordered. Due to a concern for paraneoplastic etiology of hypoglycemia. CT scan revealed a 20 cm solid mass, filling most of the pelvis and extending into the lower abdomen. Further investigations revealed normal PSA, CEA, CA19-9 and undetectable hCG and AFP levels. MRI confirmed a presence of 23 cm pelvic mass with few areas of central necrosis, extending into the lower abdomen. CT-guided biopsy revealed spindle cell neoplasm consistent with SFT. The patient underwent pelvic mass resection. Postoperatively, hypoglycemia resolved with BG readings of 138mg/dl to 178mg/dl. Surgical pathology results confirmed malignant SFT with positive STAT 6 and CD34 markers. IGF-II level obtained prior to surgery was markedly elevated at 2029 ng/ml (38-267 ng/mL). Conclusion: NICTH was described in 1930 by KW Doege and RP Potter. Less than 5% of patients with SFTs develop NICTH. Diagnosis requires manifestation of Whipple's triad, low insulin, pro-insulin and C-peptide levels, elevated IGF-II levels, or an IGF-I/IGF-II ratio>2, and the identification of the tumor. Positive immunohistochemical stain of the tumor for STAT6 confirms the diagnosis. Management involves resection of the tumor when feasible or debulking. For higher-risk tumors, radiation therapy may be considered. In inoperable cases, glucocorticoids, recombinant hGH and glucagon are recommended for palliation of hypoglycemia. Octreotide and Diazoxide are ineffective in NICTH.

7709 Ovotesticular Difference of Sex Development: Prognostic Evaluation, Sex Assignment, and Ethics

Abstract Disclosure: X. Xu: None. Y. Lin: None. B. Shivanna: None. A. Lee: None. J.C. Hakim: None. D.G. Mann: None. L.M. Noll: None. P. Georgiadis: None. S.K. Gunn: None. L.P. Karaviti: None. Background: Our case provides the identification and management of a newborn baby with ovotesticular syndrome, which was formerly known as true hermaphroditism. The term was classically derived from Greek mythology in which the deity 'Hermaphroditus', merging with the nymph Salamis, embodied both male and female attributes. The term 'true hermaphroditism' is now avoided due to its stigmatizing connotations. Ovotesticular difference of sex development (DSD) is an exceedingly rare condition, occurring in fewer than 1 in 20,000 births. This condition involves the coexistence of functional ovarian and testicular tissue within one individual, presenting a challenge in sex assignment due to unpredictable gender development. Clinical Case: This is a single case of the presence of ovarian and testicular differentiation on one side and a transitional zone of mixed pattern. Prenatal genetic testing consistent 46,XX karyotype. Initial ultrasound at the outside hospital revealed a uterus and right testicle. The baby exhibited Prader stage 4 genitalia, with a palpable gonad in the right labioscrotal area and the left gonad not palpable. Prophylactic hydrocortisone was started due to concerns regarding NR5A1/SF1 mutation. Further evaluations, including genetic tests, hormonal assessments, urinalysis and kidney ultrasound for the WT1 mutation, and scrotal and pelvic ultrasounds, were conducted. The high-dose ACTH stimulation test ruled out adrenal insufficiency. The testosterone level was in the male range, and the HCG stimulation test further confirmed functioning Leydig cells. The postnatal karyotype was 46,XX, and chromosome microarray analysis showed no abnormalities. Our approach to this case was multidisciplinary, including our endocrine experts, urologist, gynecologist, ethicist, and psychologist. We discussed the fluidity of sex assignment and addressed the degree of virilization, nature of the gonadal tissue, and emphasized the necessity of regular clinical follow-up. Our main concern was to educate the parents and protect the choices of the child. In this case, the child assumed a male sex assignment, as a result of the decision-making process between our team and the parents. In this context we did emphasize the fluidity of sex assignment. Clinical Lesson: Long-term outcomes for ovotesticular DSD remain understudied. Existing reports highlight varying rates of gender dysphoria, sexual function, and psychological well-being. Our approach to managing ovotesticular DSD involved a framework emphasizing ethical considerations and parental involvement. We advocated for and practiced a shared decision-making model involving healthcare providers, parents, and ultimately the patient. Presentation: 6/3/2024

7726 Central Adrenal Insufficiency From Inhaled Mometasone Manifesting As Growth Deceleration

Abstract Disclosure: S. Gurnurkar: None. F.I. Cooper: None. Introduction: While long courses and/or high-doses of oral steroids have been found to cause adrenal suppression and resultant insufficiency, inhaled corticosteroids from asthma management typically do not affect cortisol production. However, in this case, we describe a patient who presented with 3 years of growth deceleration and was found to have adrenal suppression from her inhaled corticosteroid/long-acting beta agonist, Dulera (mometasone furoate and formoterol fumarate). Case Presentation: An 11-year-old female with history of moderate persistent asthma presented to our endocrinology department with growth deceleration and resultant short stature. The parent noted that the child started to decelerate in height percentiles from the 50th percentile at age 8 to the 6th percentile at age 11. BMI gradually rose from the 85th to 95th percentiles. The parent noted that the child started having worsening asthma symptoms around the start of the growth deceleration, requiring a handful of oral steroid courses and the addition of daily inhaled corticosteroid, Dulera. She had remained on the Dulera for the previous three years, with her asthma under good control. She also took cetirizine daily and albuterol as needed. The last course of oral steroids was three months prior to her first endocrinology visit. The patient’s mid-parental target height was at the 50th percentile and she denied fatigue, headache, or abdominal pain. Family history was negative for endocrine conditions and short stature. Puberty began at age 10. Further workup was recommended. A bone age was concordant with chronologic age. Initial labs including a TSH, free T4, IGF-1, IGFBP-3, CBC, ESR, and CMP were within normal limits. A growth hormone stimulation test with arginine and clonidine was performed. Growth hormone peak was 11 ng/mL, but, interestingly, cortisol resulted as <1.0 ug/dl throughout the test. Due to concerns of adrenal insufficiency, she underwent a high dose ACTH stimulation test. Initial ACTH was 6.3 pg/mL (ref 6-48 pg/mL) and cortisol remained at <1.0 ug/dl at 0, 30, and 60 mins. She was diagnosed with central adrenal insufficiency and prescribed 11 mg/m2 BSA/day of hydrocortisone divided three times daily, with stress dosing and emergency hydrocortisone injection instructions. Conclusion: The existing literature suggests that Dulera (mometasone furoate and formoterol fumarate) does not significantly influence adrenal function nor growth velocity. However, we present the case of a child with 3 years of inhaled Dulera use and significant central adrenal insufficiency. This case report is the first of its kind to detail decreased adrenal function with Dulera in particular. Presentation: 6/2/2024

7799 Nesidioblastosis Concurrent with Anatomically Confirmed Metastatic Gastric Cancer

Abstract Disclosure: Y. Cho: None. K. Jo: None. J. Han: None. S. Moon: None. E. Kim: None. Background: Nesidioblastosis is a rare condition that should be considered in cases of pancreatogenic hyperinsulinemic hypoglycemia without evidence of insulinoma on imaging. We present the first case of nesidioblastosis concomitant with anatomically confirmed metastatic gastric cancer of the pancreas. Case Report A 57-year-old male presented with recurrent episodes of loss of consciousness and hypoglycemia, with a glucose level of 26 mg/dl upon arrival at the emergency room. Despite a history of advanced gastric cancer and previous chemotherapy, the patient had not been diagnosed with diabetes and was not taking medications associated with hypoglycemia. Four months prior, he underwent total gastrectomy. The fasting plasma glucose levels was 38 mg/dl, accompanied by C-peptide levels of 6.10 ng/mL, insulin levels exceeding 1000 uIU/ml, and proinsulin levels at 8.8 pmol/L. The insulin antibody level was more than 100%, and the highest cortisol level reached 15.60 ug/dL during the rapid ACTH stimulation test. The patient's postprandial 2-hour glucose level reached 233 mg/dl during the 75g glucose tolerance test. Imaging studies, including whole-body PET CT and abdominal CT, showed no evidence of suspected metastatic lesions, and the pancreas appeared normal on MRI. Endoscopic ultrasound could not be performed due to anatomical changes following the surgery. A selective arterial calcium stimulation test demonstrated a substantial over twofold increase in insulin concentrations in the gastroduodenal artery, splenic artery, and superior mesenteric artery. The patient received methylprednisolone 125 mg once daily but insulin levels remained elevated, exceeding 1000 uIU/ml, requiring continuous dextrose infusion. Octreotide therapy was initiated, resulting in an improvement in insulin levels to 589 uIU/ml, although discontinuation of dextrose fluid remained unfeasible. After consultation with the surgeon, a open subtotal pancreatectomy was performed, allowing discontinuation of dextrose on the second post-surgery day, with improved glucose and insulin levels. Histological examination showed three clusters of atypical cells with perineural infiltration. Immunostaining indicated negative synaptophysin and positive CK20, suggesting possible gastric cancer metastasis, consistent with prior gastrectomy findings. Moreover, an increased number of variable-sized Langerhans islets exhibited positive insulin and glucagon immunostaining within the islets, indicative of nesidioblastosis. Conclusion: Nesidioblastosis should be considered in cases of unexplained post-surgery hypoglycemia following metastatic gastric cancer treatment. Furthermore, given the potential link with metastatic gastric cancer, which may elude detection via imaging alone, aggressive surgical intervention should be contemplated as a nesidioblastosis treatment strategy. Presentation: 6/3/2024

6937 A Rare Case of Pembrolizumab-induced Multiple Endocrinopathies Presenting with Acute Adrenal Crisis Secondary to Isolated ACTH Deficiency - A Case Report

Abstract Disclosure: R. Abdelmasih: None. W. Pan: None. Introduction: Pembrolizumab is an immune checkpoint inhibitor (ICI) that blocks programmed cell death receptor 1 (PD-1) which took a massive leap in the oncology world. However, we are still understanding more about its immune-related adverse events (irAEs). Here we report a case of adrenal crisis due to pembrolizumab-induced hypophysitis and adrenalitis. Case Description: A 74-year-old male with a history of left renal cell carcinoma post left nephrectomy 5 years ago, complicated with lung metastasis for which Pembrolizumab was started. 5 months after, patient developed hypothyroidism and was started on Levothyroxine. 3 months later, Patient presented with lethargy and hypotension. Physical exam revealed hypotension (MAP of 55), fever, and acute encephalopathy. AM cortisol 4.2 ug/dL, Patient was started on IV pressors and a stress dose of Hydrocortisone. Hemodynamics improved, and Hydrocortisone was tapered down. ACTH stimulation test revealed a subnormal response of cortisol 0.2, 1.7, and 2.7 ug/dL at 0, 30, and 60 minutes respectively in the setting of very low ACTH of < 1.5 pg/ml, other pituitary hormones were checked, revealing normal insulin-like growth factor was 116 ng/mL, LH 15.29 mIU/mL, and FSH 27.45 mIU/mL. TSH was high 15 mIU/mL and free T4 was 1.4 ng/dl, levothyroxine dose was increased, and hydrocortisone was maintained at 10 in am and 5 in pm with excellent response. Discussion:ICIs inhibit the immunological pathways that control T-cell activation, leading to multiple immune-related endocrinopathies. Thyroiditis is the most reported one (30%), though anti-PD1-induced hypophysitis is exceptionally rare (< 1%). To date, the pathophysiology of pembrolizumab-induced central AI is not clearly understood, it’s presumed that it causes lymphocytic hypophysitis often presenting with isolated ACTH deficiency. Also, Pembrolizumab-induced primary adrenal insufficiency has seldom been reported and not yet understood, interestingly, anti-steroidogenic enzyme antibodies were absent in those few most reported cases which suggests a different mechanism compared to traditional primary AI. We suggest that our patient had combined primary and secondary adrenal insufficiency based on ACTH stim test result with very low cortisol responses in the setting of very low ACTH, which we believe is what led to such severe presentation of adrenal crisis. Diagnosis of PD1-induced AI can be challenging due to the overlapping of advanced malignancy and AI presentation. A higher level of suspicion is prompted especially in patients who experienced other endocrine irAEs (as our patient who had PDL-1-induced hypothyroidism). We present this case to shed light on this rare yet potentially fatal endocrine adverse event that can be reversed by prompt diagnosis and timely management due to the increasing use of pembrolizumab. More cases are needed for a better understanding of such a rare adverse event. Presentation: 6/2/2024

12616 Pembrolizumab-induced Autoimmune Adrenal Insufficiency: A Case Report And Literature Review

Abstract Disclosure: A. Calderon: None. E. Calderon-Martinez: None. J. Shakil, MD: None. A. Kansara: None. Immunechekpoint inhibitors (ICI)-related Primary Adrenal Insufficiency (PAI) is an uncommon entity. Compared to other endocrine-related adverse effects (irAES), antibody detection is less consistent. TPO and GAD65 antibodies are usually present in about 40-80% of the cases with hypothyroidism, hyperthyroidism, and diabetes. On the contrary, case reports and series for PAI seldom report the presence or absence of 21OH antibodies. We present a case and perform a literature review of PAI, in a patient who received pembrolizumab and developed PAI with 21 hydroxylase antibodies. A 62-year-old man with history HIV on ART (last CD4 count 590 cells/mm3) and locally advanced urothelial cancer on Pembrolizumab, presented with nausea, vomiting, abdominal pain, and decreased urine output. He was noted to be confused, and in hypoactive delirium. On admission, his chemistry panel he was noticed to have normal sodium and potassium levels. The CT scan of the abdomen revealed regional enteritis and was started on IV fluid therapy. His adrenal glands were described as normal on imaging. On the 16th day of hospitalization, the patient became unresponsive and hypotensive. He was transferred to the ICU. His sodium level was 132 mEq/L and potassium level was 6.1 mEq/L, bicarbonate level was 18 mEq/L, calcium of 10.3 mg/dl, and eosinophils of 15%. Random cortisol levels measured before administration of steroids were undetectable twice, 9 hours apart, with an ACTH level of 94. He underwent an ACTH stimulation test with cosyntropin 250 mcg IV with resulting undetectable cortisol levels after 30 and 60 minutes. CT and MRI of the brain showed no signs of hypophysitis. He was started on high-dose hydrocortisone with improvements in his mental status, hypotension, and gastrointestinal symptoms. He was discharged on hydrocortisone. His 21-Hydroxylase antibody was later found out to be positive. After combination immunotherapy regimens, CTLA-4 inhibitors are the most common to cause any irAE, however endocrine irAE particularly are mostly associated with PD-1 inhibitors. Among these, thyroid and pituitary disorders are the most common ones. Reports show that about 10% of patients receiving immunotherapy will develop endocrinopathy. ICI-induced PAI has been reported to occur in 7.6% of patients receiving combination therapy, and 2% of patients receiving Pembrolizumab. It has been reported that only 15% of patients will recover adrenal function. A meta-analysis that gathered 15 cases of ICI-induced PAI, found that only 2 cases had positive 21-hydroxylase antibodies. In our presented case, we have robust biochemical confirmation of PAI, with positive 21 hydroxylase antibody, after being on pembrolizumab for 9 months. Further information is needed to establish the pathophysiology, presentation, and prognosis of ICI-related PAI when anti adrenal antibodies are positive. Presentation: 6/1/2024

7085 Myoclonus Seizure with Pseudo-Adrenal Insufficiency as the Clinical Manifestations Leading to the Diagnosed Multi-focal Insulinomas that Mimic Multiple Endocrine Neoplasia Type 1 Syndrome

Abstract Disclosure: P. Kiatpanabhikul: None. Background: Insulinoma is a rare disease that presents with varying symptoms and can be sporadic or associated with hereditary syndromes (1). These rare points of views of insulinoma-patient on clinical manifestations, hormonal responses and surgical pathology result for final diagnosis and management. Clinical Case: A 59-year-old woman presented with myoclonic seizure of right arm with consciousness duration 5-10 minutes every midday twice a week for 6 months and generalized convulsion for 20 minutes ago. She had a low FPG level (59 mg/dL; n 70-100) and was admitted to doing 72-hour fasting test that revealed hypoglycemia at 12-hour of fasting with a nadir glucose level of 55 mg/dL, insulin 3.7 uIU/mL (cutoff > 5), C-peptide 0.4 ng/mL (cutoff > 0.6), cortisol 6.22 mcg/dL (n 5-25) and normal morning ACTH level (29.8 pg/mL; n 10-65). These were appropriated response of endogenous insulinemia with inappropriate response of serum cortisol level in hypoglycemic feature. MRI pituitary gland was considered to evaluate secondary hypocortisolism which showed a small less enhancing lesion left anterior lobe 0.3x0.45-cm without any pituitary hormonal abnormalities that were considered non-functioning pituitary microadenoma which could not explain inappropriate response of cortisol level to hypoglycemic period in this patient. Five months later, she presented at the emergency room with myoclonic seizure on her extremities, blurred consciousness and slurred speech after having lunch for 1-2 hour and revealed CPG 30 mg%, severe hypoglycemia (26 mg/dL), hypocortisolism (4.49 mcg/dL), with endogenous hyperinsulinemia (insulin 55.2 uIU/mL, C-peptide 2.5 ng/mL). 250-mcg ACTH stimulation test was done and showed normal response of her HPA-axis function (serum cortisol level at 0, 30, 60 min was 9.12, 17.87, 18.61 mcg/dL). CT pancreatic protocol showed several arterial enhancing nodules scattering at pancreatic tails isoattenuation to pancreatic parenchyma on portovenous phase up to 1.7*1.6 cm. She was operated on to distal pancreatectomy with intraoperative insulin/glucose ratio monitoring. Surgical pathology confirmed 4-well-differentiated pancreatic neuroendocrine tumors with insulin-producing, sizes 0.5-1.7 cm in diameter. Her final diagnosis was multi-focal insulinomas with non-functioning pituitary microadenoma that mimic MEN-1 syndrome without secondary adrenal insufficiency. She underwent successful surgical resection with complete resolution of symptoms during 4 years of followed-up with no recurrence and no having any hypercalcemia and hyperprolactinemia. Conclusion: Multi-focal insulinomas can be presented as sporadic, more severe hypoglycemia and endogenous hyperinsulinemia during period after meal with myoclonic seizure and pseudo-adrenal insufficiency in older-aged, non-diabetes person without recurrence after treatment for 4-year of followed-up. Presentation: 6/2/2024

7521 Unmasking of PCOS after Microprolactinoma Treatment

Abstract Disclosure: F. Erenler: None. B. Aydogan Mathyk: None. Background: PCOS and prolactinomas are two of the leading causes of secondary amenorrhea. Hirsutism is a common finding for both diagnosis and can be the presenting symptom. We are presenting a case of secondary amenorrhea, initially diagnosed with microprolactinoma without signs of hyperandrogenism, which progressed to overt PCOS after prolactinoma treatment. Case: A 22-year-old female with history of Hashimoto’s hypothyroidism presented with secondary amenorrhea. Patient was on combined oral contraception pills (COC) for menstrual regulation and discontinued them with a desire of natural cycles. After the discontinuation of COC, her menstrual cycles did not return for four months and patient was subsequently found to have a microprolactinoma with prolactin (PRL) level 70.6 ng/mL - high (nl: 2.8-29.2 ng/mL), LH 6.1 mIU/mL (follicular phase: 1.9-12.5 mIU/mL), FSH 2.4 mIU/mL - low (follicular phase: 2.5-10.2 mIU/mL), androstenedione 132 ng/mL (follicular phase: 51-213 ng/mL), testosterone 36 ng/mL (nl: 2-45 ng/mL), AMH 33 ng/mL - high (nl: 1.02-14.63 ng/mL), DHEA-S 241 mcg/dL (nl: 44-286 mcg/dL), HCG neg. MR Sella showed a 0.5 cm hypoenchancing pituitary lesion, confirming the diagnosis of prolactinoma. Patient was started treatment with cabergoline 0.25 mg twice a week and PRL level trended down to 3.9 ng/mL. With normalization of PRL, patient started complaining of new onset hirsutism without return of her menses. Ferriman Gallway score was 8. Further workup showed elevated androgen markers: LH 25.7 mIU/mL - high (follicular phase: 1.9-12.5 mIU/mL), FSH 5.0 mIU/mL (follicular phase: 2.5-10.2 mIU/mL), PRL 4.7 ng/mL -low (nl: 4.8-23.2 ng/mL), androstenedione 341 ng/mL -high (41-262 ng/mL), E2 63.4 pg/mL (nl: 12.5-160 pg/mL), AMH 22.3 ng/mL – high (nl: 1.23-11.61 ng/mL), testosterone 94.7 ng/mL - high (nl: 10-55 ng/mL), DHEA-S 261 mcg/dL (nl:110-431.7 mcg/dL). ACTH stimulation test pursued to rule out NCAH and17-OH progesterone levels were within normal range after stimulation. Pelvis US obtained due to high suspicion for PCOS and was consistent with polycystic ovaries. The diagnosis of PCOS confirmed by Rotterdam criteria. Patient has phenotype A PCOS by the definition of NIH 2012 consensus. Conclusion: Hyperprolactinemia and pituitary adenomas can cause secondary amenorrhea. In our case, the treatment of hyperprolactinemia with cabergoline unmasked the underlying PCOS. The clinical and biochemical manifestation of PCOS became apparent following the removal of prolactin’s suppressive effect on GnRH. Presentation: 6/2/2024