Ref Range Research Articles

8087 A Case Series on Thyroid Eye Disease Precipitated by the COVID Vaccine in Patients with Long-Standing Primary Hypothyroidism

Abstract Disclosure: R. Hassan: None. J. Islam: None. Background: Thyroid eye disease (TED) is an autoimmune disease characterized by progressive inflammation and damage to the tissues around the eyes, especially extraocular muscle, connective, and fatty tissue. It is most commonly seen in patients with Graves' disease. Less commonly, TED may occur in patients with hypothyroidism. Case Discussion We are presenting a case series on TED precipitated by the COVID vaccine in three patients with known cases of long-standing hypothyroidism. References ranges:TPO Ab: (Ref range: <9.0 IU/mL)TSI: (Ref range: <=1.3 TSI index)TRAb : (Ref range: 0.00-1.75 IU/L)TSH: (Ref range: 0.450-4.500 uIU/mL)Free T4: (Ref range: 0.82-1.77 ng/dL)T3: (Ref range: 87.00 - 178.00 ng/dL) CASE 1: 59 year-old female patient with 18-year history of primary hypothyroidism on levothyroxine who presented with a 5 month history of progressive ocular symptoms of double vision and “puffy eyes” along with other thyrotoxic symptoms. These occurred after receiving her second COVID-19 vaccine. Labs showed elevated TSI and TRAb (3.0, 6.32). TPO antibody was within normal limits at 0.5. Patient had undetectable TSH and free T4 within normal range (162, 1.08). CASE 2: 70 year-old female patient with 25-year history of primary hypothyroidism on levothyroxine who presented with a 4 month history of eye discomfort, eyelid blistering and ocular swelling after she receiving her first dose of COVID-19 vaccine. She was found to have increased ocular pressure per her ophthalmologist. On lab work, she was found to have elevated TSI and TRAb (7.1, 2.60). TPO antibody was within normal limits at 0.8. TSH was undetectable and free T4 were within normal range (159.76, 1.49). CASE 3: 82 year-old female with 30-year history of primary hypothyroidism on levothyroxine who started developing diplopia and proptosis over a 6 month course after she received her first COVID-19 vaccine.Labs showed elevated TSI and TRAb (5.1, 17). Her TPO antibody was within normal limits at 0.4. Her TSH was undetectable, and free T4 was within normal limits (71.76, 1.32). All three patients were started on low-dose methimazole, prednisone, and completed an eight week infusion course of Teprotumumab (Tepezza) with subsequent improvement of proptosis and diplopia. Conclusion Providers should be aware that patients with long standing hypothyroidism, who suddenly require less to no thyroid hormone replacement along with new onset ocular symptoms could be developing TED. This had previously been thought to be solely associated with Graves’ Disease but now has been seen with an uptick in incidence in patients with chronic hypothyroidism during the COVID pandemic. This is likely related to immune response that been associated with vaccines. Presentation: 6/3/2024

7081 A Spotlight on Marine Lenhart Syndrome

Abstract Disclosure: R. Alshantti: None. A.M. San Hernandez: None. J. Wu: None. C.P. Barsano: None. M.F. Siddiqui: None. Introduction: Marine-Lenhart Syndrome is a rare condition with a prevalence of 0.8-4.1% of cases with Graves’ disease. It is defined by the coexistence of Graves’ disease and autonomously functioning thyroid nodule(s). It is an under-recognized cause of hyperthyroidism. A limited number of cases have been reported in the literature. We report an interesting case of Marine-Lenhart Syndrome characterized by the presence of elevated thyroid stimulating immunoglobulins (TSI) and an autonomous right thyroid nodule. Case Description: A 37-year-old man with a history of hyperthyroidism from Graves’ disease and a right thyroid nodule was referred to endocrinology clinic. He was diagnosed with hyperthyroidism in 2015 at an outside facility. He had elevated thyroid stimulating immunoglobulins (TSI) and a 2.9 cm right thyroid nodule which was biopsied and had benign cytopathology. Hyperthyroidism was treated with methimazole (MMI) but without subsequent remission of Graves’ disease. He ran out of MMI and re-presented with symptomatic hyperthyroidism with fatigue, tremors, and hyperdefecation. There was no ocular involvement or thyroid compressive symptoms. Biochemical work up was consistent with uncontrolled hyperthyroidism (suppressed TSH 0.01 uIU/mL [Ref range: 0.45-5.33], and elevated FT4 2.58 ng/dl [Ref range: 0.70-2.20], elevated free T3 8.7 pg/ml [Ref range: 2.5-3.9], and mildly elevated TSI 0.72 IU/L [Ref range: 0.54 or less]. MMI was therefore reinitiated. Thyroid Uptake scan demonstrated an increased focal 24-hour Iodine-131 uptake of 57% in the right lobe with suppression of the left lobe. Thyroid ultrasound support the finding of large right thyroid nodule (2.3 x 2.4 x 3.9 cm) with diffuse heterogeneous thyroid. The presence of TSI, lack of control of hyperthyroidism for more than 2 years of treatment, and presence of a functioning thyroid nodule raise the suspicion of Marine-Lenhart Syndrome. Indeed, the findings of an autonomously functioning right thyroid nodule with concomitant Graves’ disease establish the diagnosis of Marine-Lenhart Syndrome. The option of RAI ablation vs total thyroidectomy was discussed with the patient. The patient opted for thyroidectomy. Conclusion: Based on studies, approximately 35% of patients with Graves’ disease have thyroid nodule(s) and only 2.7% are functioning adenomas. The combination of positive TSI or TrAb and functioning thyroid nodules has been termed Marine-Lenhart syndrome. The syndrome was named after David Marine and Carl Lenhart who initially described it in 1911. Unlike Graves’ disease, patients with Marine-Lenhart Syndrome have a lower remission rate with thioamides, require definitive treatment with RAI ablation at a high dose or total thyroidectomy, and may easily be misdiagnosed by many endocrinologists. Presentation: 6/2/2024

6402 Unsuspected Bladder Mass Turns Out To Be A Paraganglioma

Abstract Disclosure: S. Lamichhane: None. A. Flowers: None. D.T. Price: None. A. Kaur: None. Background: Urinary bladder (UB) paragangliomas are extremely rare tumors comprising of less than 0.05% of all bladder neoplasms and 10% of all paragangliomas. The diagnosis is usually suspected based on clinical features of painless hematuria, episodic headaches, hypertension, palpitations associated with micturition or bladder and confirmed biochemically by elevated urinary and/or plasma fractionated metanephrines (MN). Here, we present a case of a UB mass that was initially diagnosed on biopsy and subsequent biochemical workup revealed elevated MN. Case Report: A 64-year-old man with type 2 diabetes and hypertension, admitted for revision surgery of subdural hematoma was incidentally found to have a 3.3 x 3.4 x 3.9 cm polypoid heterogenous hyper enhancing UB mass attached to the anterior wall on CT abdomen done for abdominal pain. Cystoscopy and TURBT were complicated by hypertensive urgency. Pathology turned out to be paraganglioma. Detailed history at this time revealed a long-standing history of frequency, urgency, nocturia 4 times nightly, recurrent urinary tract infections, an episode of gross hematuria 1-2 years ago, and difficulty controlling blood pressure on 4 anti-hypertensives. Subsequently, labs showed plasma free MN of 97 pg/ml (ref range <=57), free normetanephrine (NMN) of 2392 pg/ml (ref range <=148), and total MN of 2489 pg/ml (ref range <=205). Genetic panel was negative for SDHA, SHD, AF2, SDHB, SHDC, SDHD, VHL, RET, TMEM127. He received 6 doses of Lantreotide due to suspicion of metastasis based on abdominal, pelvic, and inguinal lymphadenopathy seen on DOTATATE scan. After preparation with alpha and beta blockers, he underwent uneventful robot-assisted cystectomy with lymph node resection that resulted in a well-differentiated paraganglioma negative for margins, lymph node involvement, and extra bladder extension. A week later, MN reduced, plasma free MN 37 pg/ml, free NMN 178 pg/ml, and total plasma MN 215 pg/ml. His BP improved, and micturition-induced palpitations resolved. Conclusion: Due to the rarity of UB paraganglioma, the diagnosis can be missed and delayed. This has a serious implication due to the risk of hypertensive crisis during the surgery and increased risk of cardiovascular complications. This case highlights the need for awareness among physicians of the clinical presentation associated with UB paraganglioma, its early recognition and management. Presentation: 6/2/2024

8270 A Rare Case Of PTHrP Induced Severe Hypercalcemia Secondary To Squamous Cell Carcinoma Of Tongue

Abstract Disclosure: N. Vennelaganti: None. S. Vennelaganti: None. K. McCowen: None. Background: PTHrP-mediated hypercalcemia is often associated with solid organ malignancies and indicates a poor prognosis. The occurrence of this condition due to SCC of the head and neck, particularly of the tongue, is uncommon. This case report aims to shed light on this rare clinical presentation. Clinical Case: A 70-year-old woman with a history of tobacco use disorder, alcoholic liver cirrhosis, and a chronic fungal prosthetic joint infection presented with altered mental status and acute kidney injury. Laboratory tests revealed a corrected calcium level of 15.4 mg/dL and suppressed PTH of 3 pg/mL, indicating non-PTH-dependent hypercalcemia. Differentials considered included malignancy, multiple myeloma, 1,25 OH Vit D mediated hypercalcemia via fungal granuloma formation, and immobilization. Diagnostic evaluation revealed normal levels of 25 hydroxy Vitamin D ie: 54 ng/mL, normal kappa to lambda ratio suggestive of negative myeloma screen, normal TSH of 2.81 uIU/mL, and a low 1,25 OH Vit D level ie: 11.4 pg/mL (Ref range: 19.9-79.3 pg/mL). An elevated PTHrP concentration of 9.7 pmol/L (ref range 0-3.4 pmol/L) was noted. CT angiography performed for stroke evaluation incidentally discovered a base of tongue mass, which was difficult to appreciate on exam due to obtundation. A biopsy confirmed SCC of the tongue, and she was determined to be Stage IVA. The patient's hypercalcemia was determined to be secondary to PTHrP production from the tongue SCC compounded by immobilization. She was treated with IV fluids and subcutaneous calcitonin, normalizing her calcium levels over 20 days. IV Bisphosphonates were held inpatient due to poor renal function. She was seen by oncology and determined to not be fit for surgical management or chemotherapy. Radiation therapy was advised for management and patient was discharged. While awaiting her outpatient radiation treatment, the patient had another episode of altered mental status and was found to have a serum calcium of 16.4 mg/dL. She was managed with IV fluids, calcitonin and IV Zoledronate which improved her serum calcium. She has since been receiving monthly IV Zometa with oncology for hypercalcemia of malignancy. She was recently readmitted with severe oropharyngeal and pharyngeal dysphagia and has received a PEG tube for feeding. She is still pending radiation therapy for SCC tongue. Conclusion: Initially, during the workup of this case, we believed her hypercalcemia was likely immobilization-induced, but thorough investigation and the elevated PTHrP levels steered us towards malignancy as a potential etiology. This case is an example of an occult malignancy which lead to severe hypercalcemia. It also contributes to the understanding of hypercalcemia in cancer patients and highlights the rare association of SCC of the tongue with PTHrP-mediated hypercalcemia . PTHrP secreting SCC of head and neck are typically associated with a poor prognosis. Presentation: 6/2/2024

7655 Genetic Mysteries Unveiled: Unusual Mutation Unraveled In Hypophosphatasia

Abstract Disclosure: A. Sharma: None. P. Katikaneni: None. S. Tanveer: None. K. Selk: None. Introduction: Hypophosphatasia (HPP), an inherited dental-osseous metabolic illness, is caused by inactivating mutations in the gene encoding the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP), which leads to a decrease in TNSALP enzymatic activity. Patients with HPP typically experience dental and skeletal mineralization issues as their most common symptoms; musculoskeletal abnormalities, numerous fractures, tiredness, and migraines are less common clinical presentations. Case Report: Our 75-year-old male patient initially presented 1.5 years prior following a spontaneous T12 vertebral fracture. A bone biopsy was performed and did not reveal evidence of malignancy. Testing for SPEP/UPEP was not consistent with myeloma, and thyroid testing was also unrevealing. His alkaline phosphatase level was consistently <40 IU/L since 1999. An evaluation was done for low alkaline phosphatase and secondary reasons for bone loss. This testing did not reveal vitamin D deficiency, parathyroid disease, hypophosphatemia, laboratory evidence of celiac disease, hypogonadism, or hypomagnesemia. A vitamin b6 level was markedly elevated at 119 ng/mL (ref range 2.1-21.7) while not on supplementation. He had noticed multiple fractures as a child, but he had written them off as minor injuries. He could clearly remember breaking his right wrist and clavicle. As an adult, he had rib fractures and a foot fracture. He was unable to recollect losing his primary teeth. Almost all his teeth are crowns or implants despite taking exceptional care of them. He did not have joint hypermobility. Genetic testing revealed the patient was heterozygous for an ALPL gene variant, c.876_882delinsT. It was a variant of undetermined significance at that time. His daughter also was found to have a low alkaline phosphatase and the same genetic test result. She also has experienced dental carries and joint pain. Our patient initiated teriparatide due to the need for more urgent therapy for extensive spinal surgery. He was later transitioned to asfotase alfa therapy and has not had any further fractures at the time of this report. Discussion: Hypophosphatasia is a rare inborn disorder due to mutations in the tissue nonspecific alkaline phosphatase gene ALPL and is characterized by low ALP levels. Affected individuals will also have elevated vitamin b6 levels and urinary phosphoethanolamine (PEA) levels. Early diagnosis of HPP is necessary to prevent bone fracture pain and improve quality of life. Inaccurate assessments can miss diagnoses of parents and other family members and even lead to lost opportunities to treat a patient with a substantial illness burden. This case highlights the mutation c.876_882delinsT as a likely pathologic variant in the ALPL gene. It also supports that patients with HPP can also respond to teriparatide treatment. Presentation: 6/2/2024

6692 Proarrhythmic Risk Of Hypoglycemia; A Case Of Insulin-Induced Hypoglycemia Provoking Torsade De Pointes-Cardiac Arrest

Abstract Disclosure: A.M. San Hernandez: None. A. Adelkhanova: None. H. Ashraf: None. J. Aguayo Herrera: None. M.F. Siddiqui: None. Introduction: Torsade de Pointes is a life-threatening polymorphic ventricular tachycardia which is associated with QTc prolongation caused by medications, metabolic and electrolyte abnormalities. Very few cases of hypoglycemia causing QTc prolongation and Torsades de Pointes have been reported in the literature. Although the mechanism is unclear, the effects of low blood glucose have been proposed to induce a sympathetic response, hypokalemia and calcium disturbances. We report a case of an insulin-induced hypoglycemia causing Torsades de Pointes cardiac arrest, highlighting the proarrhythmic risk of hypoglycemia. Case presentation: A 57-year-old female with a history of Insulin-dependent Type 2 Diabetes Mellitus (DM) was brought in by EMS due to severe symptomatic hypoglycemia (POC blood glucose of 30 mg/dL), requiring treatment with dextrose. Patient reported reduced oral intake due to vomiting for 1 week and continued insulin administration without self-monitoring of blood glucose. Laboratory work up on presentation revealed severe hypoglycemia VBG= 55 mg/dL and mild hypomagnesemia Mg=1.4mg/dL (Ref Range 1.7-2.2mg/dl) which was treated. There was no hypokalemia or hypocalcemia. ECG showed sinus rhythm with prolonged QTc interval of 573ms and non-specific ST changes.Few hours later, patient developed torsades de pointes, requiring ACLS resuscitation. ROSC was achieved after two rounds of CPR. Patient received dextrose infusion to maintain euglycemic state. She was not taking any QTc prolonging medication. There was no history of autoimmune disease. Except for hypoglycemia, no other metabolic abnormality could be identified. Cardiac and pulmonary etiologies of cardiac arrest were ruled out. Post-ROSC ECG showed sinus tachycardia with normalization of QTc to 454ms. Thus, Insulin-induced hypoglycemia was appointed as the main culprit for her cardiac arrest, in the setting of QTc prolongation. Patient received diabetes self-management and hypoglycemia education. Conclusion: Several studies support strong correlation between hypoglycemia and arrhythmic events during bedtime in people with diabetes “The dead in bed syndrome”. Hypoglycemia causes an acquired long QT syndrome independent of other risk factors such as cardiac autonomic neuropathy. Possible mechanisms include; sympathoadrenal activation, which regulates potassium, calcium and chloride channels or altered autonomic regulation caused by hypoglycemia itself regardless of the effect of insulin or hypokalemia. QT prolongation is a risk factor for sudden cardiac death by causing torsades de pointes ventricular tachycardia (VT).People with insulin dependent diabetes are at high risk of hypoglycemia and should be cautioned about the proarrhythmic risk of hypoglycemia. Education is crucial, and Continuous glucose monitor (CGM) is a valuable tool to be use in such a patient population. Presentation: 6/3/2024

7988 A Case of Spontaneous Pituitary Hemorrhage in Late Pregnancy

Abstract Disclosure: D. Poudyal: None. G.L. Prince: None. Background: Pituitary apoplexy (PA), caused by hemorrhage into the pituitary gland, is rare. The prevalence in pregnancy is also quite rare, with PA complicating 1 in 10,000 pregnancies. PA usually occurs in patients with pre-existing pituitary adenomas. Spontaneous pituitary hemorrhage (PH) causing PA in the absence of a known adenoma or other precipitating factors is less frequently described. Presenting symptoms of PA are non-specific and can pose diagnostic challenges, yet PA must be managed urgently and decisively due to the risk of life-threatening hormonal deficiencies that can ensue. Physiologic changes in pregnancy pose additional challenges in evaluating and managing patients with possible PA. Here we present a case of spontaneous PH during the third trimester of pregnancy in the absence of pre-existing pituitary pathology or known precipitants. Case presentation: A 31-year-old female, G2P1, with an uncomplicated first pregnancy, presented with acute-onset headache and vision loss at 36 weeks gestation. Her symptoms resolved spontaneously in 45 minutes. MRI brain without contrast showed hemorrhage within the left aspect of the pituitary gland, a mildly displaced infundibulum, but no mass effect on the optic chiasm. MRI brain obtained 1 year prior for headache was unremarkable. Lab work showed an 8AM cortisol of 19 ug/dL (Ref range 3.7 - 19.4 ug/dL), and a total T4 of 11.3 ug/dL (Ref 4.9 - 11.7 ug/dL). Ultimately, interpretation of her cortisol testing was limited by: elevated cortisol-binding globulin in the high-estrogen state of pregnancy, elevated cortisol production by an intact hypothalamic-pituitary-adrenal (HPA) axis during the latter portion of pregnancy, and the lack of validated cutoff values for 8AM serum cortisol levels during pregnancy. In light of these factors and the risk of undiagnosed adrenal insufficiency (AI), she was treated empirically with oral hydrocortisone. Subsequently, she had an uneventful vaginal delivery, supported by stress dosing of her steroids. Postpartum, she had a normal 8AM cortisol level of 14 ug/dL, and she was noted to quickly begin breastfeeding without incident. Conclusion: PA remains a critical diagnosis that cannot be missed in patients presenting with concerning symptoms and signs, in order to identify and treat life-threatening hormonal deficiencies. Pregnancy poses unique challenges in diagnosing hormonal deficiencies such as AI due to normal physiologic changes affecting the HPA axis as well as other pituitary axes. Therefore, the benefit of empiric hydrocortisone treatment likely outweighs any associated treatment risk in cases with consistent symptomatology and radiographic findings. Presentation: 6/2/2024

7077 A Rare Case Of Hypophosphatasia Presenting With Osteoporosis In A Young Female Patient- Diagnostic Delay In Hypophosphatasia

Abstract Disclosure: R. Abdelmasih: None. I. Ali: None. Introduction: Hypophosphatasia is a rare hereditary cause of secondary osteoporosis that affects 1/100.000 individuals. The rate of osteoporosis due to hypophosphatasia is probably underestimated as it likely goes undiagnosed in heterogeneous or milder cases. We present a case of Hypophosphatasia that presented initially with osteoporosis and went misdiagnosed for years with intermittent treatment of Bisphosphonate, luckily with no atypical fractures that prompted different course of management for osteoporosis. Case Presentation: A 44-year-old female with a history of rheumatoid arthritis and osteoporosis diagnosed 7 years prior and treated with intermittent bisphosphonate which was discontinued due to side effects including muscle aches and bone pains, presented to our endocrinology clinic to establish care for osteoporosis. Patient denied prior fractures. She reported jaw pain that is being evaluated by otolaryngology and a dentist. Family history is negative. DEXA scan showed Z scores of -1.1, -1.8, and -2.2 of the lumbar spine, femoral neck, and total femur respectively. Laboratory workup showed consistently low alkaline phosphatase (ALP) 25, 20, <20 U/L (ref range 34-123), elevated Vitamin B6 of 167 nmol/L (ref range 20-125), normal parathormone, calcium, phosphate, Vit D, magnesium, and liver enzymes. Genetic testing was sent for Tissue non-specific alkaline phosphatase (TNALP). Hypophosphatasia was diagnosed based on clinical and laboratory findings, patient was started on Asfotase alfa. Clinical course is to be followed. Discussion: Hypophosphatasia is a rare hereditary disorder due to mutation of (TNALP). In normal induvial, TNALP breaks down pyrophosphate to phosphate. It also plays a role in transferring Vit B6 into the tissues. Hence, clinical presentation due to impaired calcium-phosphate hemostasis is broad including musculoskeletal pain, pseudofractues, dental abscess, and neurological symptoms (due to accumulation of Vit B6). The clinical picture varies depending on the heterogenicity of ALPL mutation. Genetic testing is not mandated to establish diagnosis, clinical presentation and laboratory testing including low ALP and elevated Vit B6 are sufficient. However, genetic testing and counseling are recommended for the patient’s sake and their family members. Antiresorptive bone therapy is contraindicated due to a further decrease of bone turnover with reported cases of increased risk of atypical femur fracture, Bone density is reported to improve with enzyme replacement therapy with bone-targeting recombinant alkaline phosphatase (Asfotase Alpha), if further treatment is needed, anabolic treatment is preferred. We present this case to shed light on such a rare disease to decrease rates of underdiagnosis or delayed diagnosis in young patients presenting with osteoporosis for prompt treatment and improved quality of life of these patients. Presentation: 6/2/2024

FRI204 A Rare Case Of Cushing Syndrome In Pregnancy: Diagnosis And Therapeutic Challenges

Abstract Disclosure: Z. Cardona: None. E.D. Szmuilowicz: None. Introduction: Cushing’s syndrome (CS) rarely occurs during pregnancy, and diagnosis of Cushing’s syndrome in pregnancy is challenging due to physiologic changes during gestation. CS is associated with severe maternal and fetal complications. Clinical Case: A 36-year-old woman presented at 21 weeks gestational age with a known adrenal nodule admitted for evaluation of HTN, bilateral lower extremity edema, transaminitis, hyperglycemia, and acute hypoxemic respiratory failure. Reported proximal muscle weakness, facial swelling, anxiety, depression, perspiration, and headaches associated with HTN. Physical exam notable for mild supraclavicular fat deposition, chest and neck plethora, hypertrichosis, and bruising. CT abdomen pelvis revealed a 2.3-cm left adrenal nodule measuring 30 Hounsfield units. Biochemical evaluation included a plasma renin activity of 0.719 ng/mL/h [ref range: 0.167-5.380 ng/mL/h], aldosterone <1.0 ng/dL [ref range: 0.167-5.380 ng/dL], potassium 2.6 mEq/dL, free plasma metanephrines (MN) < 25 pg/mL [ref range: < or = 57 pg/mL], free normetanephrines (NMN) < 25 pg/mL [ref range: < or = 148 pg/mL, total free MN and NMN < 25 [ref range: < or = 205 pg/mL]. 24-hour urine free cortisol (UFC) was markedly elevated at 1854.1 mcg/24h [ref range: 3.1-50.0 mcg/24h], repeat 2186.2 mcg/24h, ACTH: 1.5 pg/mL [ref range: 7.2-63.6 pg/mL], confirming a diagnosis of ACTH-independent CS. Her case was complicated due to the adrenal nodule location. Patients with left adrenal nodules are at risk of developing inferior vena cava (IVC) syndrome during left adrenalectomies, especially in the third trimester, due to compression exerted by the uterus while lying on the right side during the procedure. She underwent an uncomplicated laparoscopic left adrenalectomy. Was started on hydrocortisone (HC) following surgery. There was concern for transient neonatal adrenal insufficiency at delivery. Measuring adrenal insufficiency in utero is challenging; however, estriol could serve as a surrogate marker of fetal adrenal function. Her estriol was normal, possibly indicating intact fetal adrenal activity. She had an uncomplicated vaginal delivery with no signs of adrenal insufficiency in her baby. Interestingly, she had a severely low alkaline phosphatase (ALP) which completely normalized soon after adrenalectomy. Clinical Lesson: This case depicts the challenges in managing CS in pregnancy and its repercussions regarding maternal, fetal, and delivery outcomes. Additionally, it highlights the importance of implementing a multidisciplinary approach, including obstetricians, endocrinologists, endocrine surgeons, and pediatricians, to ensure the optimization of therapeutic strategies. Presentation: Friday, June 16, 2023

THU458 Demineralization Zebras: A Rare Case Of Hypophosphatasia In An Adult Presenting With Osteopenia

Abstract Disclosure: B.P. Ramchandani: None. A. Khan: None. H. Aftab: None. Introduction: Hypophosphatasia (HPP) is a rare genetic bone disease with only 500-600 cases reported in the United States. It is characterized by mutations in the tissue non-specific alkaline phosphatase (TNSALP) gene, leading to impaired bone mineralization. HPP presenting in the perinatal period is fatal. During infancy, rachitic deformities develop by age 6 months. Children present with early loss of deciduous teeth and delayed milestones while in adulthood, HPP is characterized by recurrent fractures, osteoporosis, and muscle weakness. We describe a case of HPP diagnosed in a patient after low ALP was discovered on laboratory testing. Case: A 69-year-old female presented for the evaluation of osteopenia. She had a history of fracture of the right knee as well as fracture of the base of the right 5th metatarsal and lateral aspect cuboid, which healed well with conservative management. Dental history was significant for 5 implants over the last 15 years. She was on vitamin D supplements and had also taken risedronate for osteopenia for 14 years which was discontinued at her first visit with us. Family history was significant for osteoporosis in her mother. Initial lab studies were significant for an ALP of 29 U/L (ref range 39-113 U/L), phosphate of 4.9 mg/d (ref range 2.4-4.8 mg/dl), pyridoxal 5’-phosphate level (vitamin B6) of 308 nmol/L (ref range 20-125 nmol/l), a vitamin D 25-OH level of 20 ng/mL (ref range >30 ng/ml) and PTH of 49 pg/dl (ref range 15-88 pg/ml). Repeat lab testing done 6 months after stopping risedronate showed consistent similar results with an ALP of 32 U/L, phosphate level of 5.1 mg/dl, vitamin B6 level of 349 nmol/L, and vitamin D 25OH level of 26 ng/mL. Bone density scan revealed a lumbar spine BMD of 1.503 g/cm2 (T-score 2.5) and a mean total hip BMD of -0.3 consistent with osteoporosis of spine and osteopenia of hip. Genetic testing and counseling were offered to the patient, however she declined. Discussion: Our patient presented with recurrent fractures and loss of dentition requiring multiple dental implants in the background of osteopenia. Given persistently low serum ALP and elevated serum vitamin B6 levels her presentation suggested a diagnosis of HPP. Management includes supportive treatment with prompt treatment of fractures, and routine dental care. Although there is no approved medication for adults, enzyme therapy replacement with asfotase-alfa (a recombinant human ALP) is FDA-approved for pediatric-onset HPP which improves bone mineralization and muscle strength, however discontinuation of therapy leads to reappearance of bone hypomineralization. Once the diagnosis is made, genetic testing and counseling should be offered to prevent complications in future pregnancies. Presentation: Thursday, June 15, 2023

SAT496 Tobacco Smoking May Mimic Subclinical Hyperthyroidism

Abstract Disclosure: R. Alshantti: None. U. Rafat: None. B. Alkhaurri: None. C.P. Barsano: None. M. Siddiqui: None. Introduction: Studies have shown lower levels of TSH in smokers and a positive association of smoking with hyperthyroidism. The urinary nicotine level is reported to be negatively correlated with TSH. Moreover, smoking cessation have shown reversible effects on thyroid functions and risk of having overt hypothyroidism increased more than 6-fold in the first 2 years after cessation of smoking. Whether transient smoking cessation, prior to blood work would alter thyroid functions is unknown. We report the case of an elderly woman who had normalization of suppressed TSH after smoking abstinence prior to her blood work, suggestive of smoking-induced alteration of the TSH level. Clinical Case: A 77- year-old woman was referred to endocrinology clinic for an abnormal TSH level. She had a suppressed TSH <0.01 uIU/mL [Ref range: 0.45-5.33], with normal free T4 0.78 ng/dl [Ref range: 0.70-2.70], and free T3 3.66 pg/ml [Ref range: 2.5-3.9], consistent with subclinical hyperthyroidism. Thyroid auto-antibodies were negative. She had a long-standing history of multinodular goiter with mild tracheal deviation for which she had declined surgical management. She was an active smoker with 40 pack years smoking history. There was no preceding viral illness. She was not taking any biotin-containing supplements or medications that would interfere with thyroid hormones. The patient denied symptoms of overt hyperthyroidism. On physical examination she had a large multinodular goiter with negative Pemberton’s sign. There was no exophthalmos, lid lag, tachycardia, tremors or hyperreflexia. Her subsequent blood tests, 2 and 4 months apart, were also consistent with subclinical hyperthyroidism with TSH levels of 0.115 to 0.144 uIU/mL with normal free T4 0.72 ng/dl and total T3 136.3 to 153 ng/dl [Ref range 80-187]. Based on her age, she met the treatment threshold. However, as the patient continued to smoke 10 cigarettes daily, even on the days when thyroid labs were drawn, treatment was deferred considering the possibility of smoking-induced altered thyroid function. Blood work re-drawn after a smoking abstinence of 10-12 hours showed normalization of TSH 0.58 uIU/mL consistent with a euthyroid state. Conclusion: When evaluating patients with abnormal thyroid functions, it is important to address smoking status. Cigarette smoking may alter thyroid function tests in a pattern consistent with subclinical or overt hyperthyroidism and its effect on thyroid functions may be transient and reversible. Therefore, the possibility of smoking-induced alteration of thyroid functions should be considered in active, clinically euthyroid smokers. It may be judicious to hold treatment with thionamides in such patients and to re-evaluate thyroid functions after smoking abstinence. Presentation Date: Saturday, June 17, 2023

FRI556 Thyroid Autoimmunity Leading To Premature Ovarian Insufficiency (POI) In A Euthyroid Young Woman

Abstract Disclosure: P. rimal: None. M. Moeed: None. C. Musurakis: None. A. Ojha: None. W. Akhtar: None. C.P. Barsano: None. M.F. Siddiqui: None. Introduction: Premature Ovarian Insufficiency is rare in young women and affects only 0.1% before the age of 30. The causes of POI in most cases remain unidentified, with autoimmunity being responsible for 4-30% of the cases. We present the case of a young euthyroid woman who presented for the evaluation of primary amenorrhea and diagnosed with POI associated with thyroid autoimmunity. Clinical Case: A 28-year-old Afghani woman with no known co-morbidities was referred to endocrinology clinic for the work up of primary amenorrhea. She was a goitrous and had normal secondary sexual characteristics and a history of withdrawal bleeding with OCP. There was no known personal or family history of autoimmune disease. Work up revealed hypergonadotropic hypogonadism with high FSH, 55 mIU/ml[Ref range for postmenopausal woman 16.7-113], high LH, 20.28 mIU/ml [Ref range for postmenopausal woman 10.8-58.69] and low estradiol, <2 pg/ml. Anti-Mullerian hormone was low, <0.08ng/ml [RefRange 0.69-13.39] signifying inadequate ovarian reserves and pelvic ultrasound confirmed atrophic ovaries. Etiological work up revealed normal female karyotype, 46XX, and negative FMR gene mutation testing for Fragile X syndrome. Thyroid functions were normal TSH, 3.3 mIU/L (0.27-4.2) and Free T4, 1.29 ng/dl[Ref Range 0.70-2.7]. Autoimmune work up was negative for adrenal 21-OH antibody and anti-ovarian antibodies. However, patient had strongly positive thyroid peroxidase (TPO) antibodies, 613.77 mIU/L[Ref range 0.0-9.0] consistent with thyroid autoimmunity. DXA scan revealed osteopenia. Thus, the diagnosis of POI associated with thyroid autoimmunity was established. HRT with estradiol patch and progesterone was initiated. Calcium, Vitamin D supplements and fertility counseling were provided. Conclusion: Thyroid disease is the most common autoimmune disease associated with POI. Studies have shown higher risk of POI and infertility in patients with Hashimoto’s and Graves’ diseases with co-existing high titers of TPO or anti-thyroglobulin antibodies. Ovaries are subject to autoimmune attack that leads to diminished ovarian reserves. However, until now the association of isolated elevation of TPO antibodies with POI has not been established. A Study by Osuka et al. did not find any significant difference in AMH levels between TPO and non-TPO positive euthyroid women and concluded that unlike hypothyroid women, thyroid autoantibodies were not likely to influence ovarian reserves in euthyroid women. Our case is unique where POI is associated with isolated elevation of TPO antibodies in the absence of clinical thyroid disease. This signifies the possibility that ovarian failure may precede the onset of thyroid disease in patients with thyroid autoimmunity and should be suspected and treated at an early stage, before ovarian reserves are diminished. Presentation: Friday, June 16, 2023

SAT546 Papillary Thyroid Cancer Surveillance: Thyroglobulin Levels Affected by HAMA

Abstract Disclosure: J. Sanchez Perez: None. M. Obeid: None. M. Fariduddin: None. D.J. Toft: None. Introduction: Thyroglobulin (TG) measurement is a major means of detecting recurrence of previously treated differentiated thyroid cancers. Human-Anti Mouse Antibodies (HAMA) can interfere with lab measurements of TG levels and affect clinical decisions and treatment for these cancers.Clinical Case: A 65-year-old female was diagnosed with papillary thyroid cancer (PTC). Surgical pathology following total thyroidectomy demonstrated a tumor of 3.5 cm in its greatest dimension, unifocal, without invasion of locoregional tissue classified as Stage I (pT2N0M0) per AJCC 8th edition. Radioiodine whole body scan (WBS) demonstrated iodine uptake in the neck and 126.5 mCi of I-131 was given. In surveillance 5 years later, TSH was found to be 0.17 mcIU/ml (ref range: 0.35 - 4.00) TG 64.7 ng/ml (ref range: 1.3 - 31.8 ng/mL), and anti-Tg antibodies were undetectable. Neck US consistently showed nonspecific findings of stable small nodes with normal morphology in both supraclavicular regions. Given elevated TG levels, 250 mCi of I-131 was given. Follow-up TG levels ranged from 27.8 to 36.4 ng/ml. A repeat WBS did not reveal any uptake, but as TG remained elevated, I-131 (238 mCi) was again given. Subsequent TG throughout the following 15 years ranged from 2.8 - 58.6 ng/ml. Repeat Neck US only showed benign-appearing lymph nodes. WBS did not have any focal activity to suggest recurrent disease and PET/CT did not show any abnormal FDG uptake. The persistently high TG levels without clinical evidence of tumor recurrence raised the suspicion of lab interference. The serum sample was treated with a blocking reagent that contained mouse immunoglobulin after which the TG level decreased to 2.7 ng/ml compared to untreated value of 20.5 ng/ml.Conclusion: HAMA are human antibodies against mouse antibodies which are believed to develop in humans from direct contact with rodents, including mice, and from the recent increase in the use of mouse monoclonal antibodies for diagnostic and therapeutic purposes. These antibodies implicate an unexpected source of interference in immunoassays, as seen in our patient, which can confound laboratory results and create a clinical dilemma. This patient with PTC had a complete radiological response after surgery, but an incomplete biochemical response which caused the patient to be given a total of 614 mCi of I-131. This case highlights the importance of recognizing the possible presence of HAMA when analyzing TG levels, particularly when the TG levels are used for treatment decisions. Presentation Date: Saturday, June 17, 2023

THU227 Isosexual Peudo-precocious Puberty Due To Leydig Cell Tumor In A Prepubertal Child

Abstract Disclosure: M. Baby: None. A. Xu: None. N. Shacham: None. E. Shapiro: None. B.C. Shah: None. Background: Testicular tumors account for 2-4% of all childhood cancers. Leydig cell tumors are the most common form of sex cord stromal tumors and represent 1-3% of all testicular tumors. In the pediatric population, testicular Leydig cell tumors present with signs of precocious puberty. Workup reveals low gonadotropins with elevated testosterone and testicular mass on ultrasound. Treatment involves surgical enucleation (partial orchiectomy) in most cases. Clinical case: We present the case of a 4 year 10 month old male who presented to endocrine clinic for precocious puberty. He developed pubic hair three months prior with body odor. He did not have any CNS symptoms including headaches or visual changes. There was no use of exogenous androgens at home. He was born full term, small for gestational age with an uncomplicated postnatal course. There was no family history of precocious puberty. Height was at the 99th percentile (z-score 2.7), weight 98th percentile (z-score 2.07), and BMI 86th percentile (z-score 1.09). On exam, he was lean and appeared muscular. His testes were asymmetrical with the right testicle measuring 3 ml and the left testicle 2 ml. Scrotal hair was curly and sparse, Tanner III. Stretched penile length was 7 cm (90th percentile), width was 3.2 cm. Results: Bone age was advanced to 10 year 0 months with height age of 7 year 3 months. Serum gonadotropins were low, testosterone was pubertal at 115 ng/dl (Electrochemiluminescence Immunoassay). Serum 17-hydroxyprogesterone (221 ng/dl, ref range 0-90 ng/dl) androstenedione (163 ng/dl, ref range = < 51 ng/dl), and IGF-1 (368 ng/ml, ref range 108 – 293 ng/ml) were elevated. ACTH, cortisol, thyroid profile, and prolactin were normal. Beta-HCG and AFP were negative. ACTH stimulation test showed normal response. Testicular ultrasound with doppler was performed; right testicle measured 1.82 x 1.06 x 1.36 cm, volume of 1.4 ml, while left measured 1.27 x 0.72 x 0.87 cm, 0.4 ml. Within the right testicle, there was a mass that was hypoechoic, vascular (with a testicular artery feeding branch in the periphery), multinodular and measured 1.2 x 0.8 x 1.10 cm (0.53 ml). He was referred to urology and underwent enucleation of the right testicular mass through an inguinal approach. Grossly, the mass appeared tan and lobulated and surgical pathology confirmed a benign Leydig cell tumor. The patient recovered well and post-operative serum testosterone level at 2 weeks was <2.5 ng/dl. Conclusion: We present a case of a testicular Leydig cell tumor that presented as peripheral precocious puberty marked by low gonadotropins and elevated testosterone with ultrasound findings of a vascular mass with testicular artery feeding branch in the periphery. Early detection of a Leydig cell tumor is crucial as it can be treated by enucleation thus salvaging the testes. Presentation: Thursday, June 15, 2023

SAT333 A Case Of Pheochromocytoma Initially Presenting As Takotsubo-like Cardiomyopathy

Abstract Disclosure: J.S. Figueroa: None. S.W. Holland: None. J. Cheng: None. M.C. Sullivan: None. Background: Takotsubo-like cardiomyopathy (TCM) is a known but rarely seen clinical complication associated with pheochromocytoma that is important to recognize. Case Presentation: A 68 year old woman with a history of hypertension on verapamil, lisinopril-hydrochlorothiazide, clonidine, hyperlipidemia, asthma, and chronic kidney disease presents for nausea and vomiting associated with pressure like chest pain. Cardiac work up revealed elevated troponins and T wave inversion in the anterolateral leads concerning for non-ST segment elevation myocardial infarction (NSTEMI). CT Abdomen study revealed two right sided adrenal nodules 2.4 x 1.8 cm and 1.9 x1.1 cm. Coronary angiography was normal but study was concerning for TCM. She developed new onset atrial fibrillation and was treated with calcium channel blocker and beta blocker. Transthoracic echocardiography showed apical hypokinesis and a mildly decreased ejection fraction of 41%. She was discharged home on beta blocker and losartan therapy. The patient presented 5 days later with similar symptoms and a maximum elevated blood pressure 170/110 mm Hg. Labs revealed elevated plasma free metanephrines level of 505 pg/ml (ref range ≤57 pg/ml) with normal renin, aldosterone, and cortisol levels. CT adrenal protocol study showing pre-contrast density of largest nodule 39 Hounsfield units (HU), postcontrast density 81 HU, and washout density 56 HU with washout at 59.5%. The smaller nodule had pre-contrast density of 31 HU, postcontrast of 65 HU, washout density of 61 HU with washout at 11.8%. Endocrine and Endocrine surgery were consulted at this time. Alpha blocker tamsulosin was initiated and beta blocker therapy was discontinued. Patient underwent right adrenalectomy with subsequent improvement of her ejection fraction two months later. Histology was concerning for malignancy for which she is currently being followed. Conclusion: This case highlights TCM as a presenting sign for a pheochromocytoma. A study by Agarwal et al. found that a minority of patients who had TCM due to pheochromocytoma developed symptoms typical of the tumor such as headache, hypertension, palpitations, and diaphoresis. The study also found that complications such as cardiogenic shock and heart failure were higher in pheochromocytoma related TCM.¹ Consider catecholamine producing tumors as a potential cause of TCM where appropriate alpha and beta blockade may help to reduce symptoms. Earlier recognition of a potential pheochromocytoma would also have discouraged the use of a beta blocker initially until pheochromocytoma was ruled out. An individualized, multidisciplinary approach helps lead to a timely diagnosis and appropriate treatment decisions for these rare tumors. References (1) Agarwal, V.,Kant, G.,Hans N., Messerli F.H. Takotsubo-like Cardiomyopathy in Pheochromocytoma. International Journal of Cardiology 2011; Vol 153,3,241-248 Presentation: Saturday, June 17, 2023

FRI691 Intrathyroidal Parathyroid Adenoma With Congenitally Absent Contralateral Thyroid Lobe Treated With Thermal Ablation

Abstract Disclosure: L. Bilandzic: None. L. Bilandzic: None. H. Korkusuz: None. We present a rare case of primary hyperthyroidism with ectopic adenoma located in the right thyroid lobe with congenitally absent left thyroid lobe which was treated with thermal ablation. A 60-year-old woman was referred to endocrinology clinic for further evaluation of her elevated total serum calcium of 11.4 mg/dL (reference range 8.5-10.5), elevated parathyroid hormone (PTH) level of 106 (10-60 pg/mL). Bone mineral densitometry showed a total T score of -2.9 in L1-L4. Other results were vitamin D 25-OH 30 ng/mL (ref. range 30 - 100), TSH 3.36 µIU/mL (ref range 0.4-5.0), eGFR 83 (normal > 59 mL/min/ 1.73 m²). She was asymptomatic and had no history of kidney stones. Other causes of hypercalcemia were refuted. Given the osteoporosis in her lumbar spine, parathyroid localization and surgery were suggested. Thyroid and parathyroid sonography demonstrated a solid hypoechoic nodule in the right thyroid lobe, 12x10x11mm, with smooth margins, no calcifications, classified as ACR TI-RADS T4. Left thyroid lobe was not appreciated and was considered to be congenitally absent since the patient did not have a history of a previous thyroid resection. Further localization studies (99mTc Sestamibi parathyroid scintigraphy and 4D-CT of the neck) did not reveal any other possible candidates for parathyroid adenomas. Eventually, a fine needle aspiration of the nodule in the right thyroid lobe was performed. PTH needle wash showed a PTH value of 633 pg/mL whereas the PTH value ≥ 100 pg/mL is suggestive of the presence of PTH secreting tissue. Given the thyroid anatomy found with this patient, a right lobe hemithyroidectomy would result with a permanent substitution dependent hypothyroidism. As an alternative, thermal ablation was presented as a treatment option for which the patient opted. She underwent the procedure in local anesthesia. Sonographic imaging of the adenoma was followed by the percutaneous insertion of the coagulation electrode. The utilized high frequency ablator was used with an output of 9 to 40 W and a frequency of 470 ± 10 kHz. There were no complications developed during or after the procedure. Two weeks after the thermal ablation, PTH level was measured at 55 pg/mL, total serum calcium at 9.5 mg/dL, TSH 1.01 µIU/mL. Sonography showed a hyperechoic nodule at the former location of the parathyroid adenoma, which was evaluated as a scar tissue. Three months after the procedure total calcium was at 9.3 mg/dL, PTH at 58 pg/mL, hence no biochemical evidence of pHPT. This is a rare case of ectopic parathyroid adenoma located in the thyroid gland with hemi agenesis of the contralateral lobe. A minimally invasive thermal ablation was performed with the goal of inactivation of the adenoma and preserving the euthyroid function. Presentation: Friday, June 16, 2023

FRI268 Late Onset Polyglandular Autoimmune Syndrome Type 2

Abstract Disclosure: M.S. Nicholson: None. A. Barnett: None. A 66-year old white female was admitted for weakness, acute kidney injury, and hypotension. This is her 3rd hospital or ER visit in the last 12 months for similar complaints. She has a 25 year history of type 2 diabetes on insulin and oral therapy and 30 year history of hypothyroidism on levothyroxine 75 mcg daily. She was on oral estrogen replacement therapy for post-menopausal symptoms with a hysterectomy in her early 50s. She has a sister with type 2 diabetes on oral meds and hypothyroidism. She has a brother with type 1 diabetes. Her serum sodium was 135 mmol/L (135-145), potassium was 5.4 mEq/L (3.5 -5.1), and calcium was 9.2 (8.5-10.1). Her Creatinine was 1.2 with a GFR of 48. A random cortisol in the ED was 9.2 (no ref range). Blood pressure was low and she was tachycardic and her weight was 68 kg. She was a well developed female with a a tanned complexion. Areas of vitiligo were noted on her arms. A cosyntropin stimulation test was done midday with a baseline, 30, and 60 minute cortisol levels of 9.2, 8.8, and 9.3 respectively. Baseline ACTH was 877.6 pg/mL (7.2-63.6). Her TSH was 4.09 mIU/mL (0.358-3.74) and free T4 was 1.29 ng/dL (0.76-1.46). DHEA-S was 14 mcg/dL (13-130). She was started on stress dose steroids with rapid improvement in BP, hyponatremia, and symptoms. GAD-65 antibodies were above 250 IU/mL and 21-hydroxylase antibodies were positive. Her TPO antibodies were negative. Non-insulin diabetes medications were stopped and she was discharged home after stabilization on prednisone 5 mg daily and fludrocortisone 0.1 mg daily. This patient has an atypical presentation of polyglandular autoimmune syndrome type 2 (PAS2). She presented with an Addisons crisis at the age of 66. She was already diagnosed with hypothyroidism and insulin requiring diabetes and evidence of vitiligo. A majority of patients with PAS2 are female and present in their 20s to 40s with primary adrenal insufficiency and primary hypothyroidism. Her initial manifestation was hypothyroidism and then diabetes and vitiligo with adrenal insufficiency many years later. Her random cortisol was not suppressed and this lead to a delay in her diagnosis. This was likely due to oral estrogen therapy raising cortisol-binding globulin. Her elevated baseline ACTH and lack of response to ACTH stimulation confirmed her diagnosis of primary adrenal insufficiency. An ACTH stimulation test was repeated as an outpatient with similar response. This case highlights the importance of provocative testing for adrenal disorders and testing for autoimmune causes of endocrine disorders when patients are not responding as expected. Presentation: Friday, June 16, 2023

PMON39 A Perfect Storm – Multiple Causes of Hyponatremia in Patient With Pituitary Macroadenoma

Abstract Introduction Adrenal insufficiency is a life threatening condition, and prompt diagnosis and treatment are necessary. Here we present a case of hyponatremia which was thought to be multifactorial due to secondary adrenal insufficiency in the setting of a pituitary macro-adenoma, central hypothyroidism, SIADH in the setting of nausea as well as analgesic use. Case presentation A 23 y.o female patient presented to the hospital with headaches. MRI of the head revealed a 2.2 cm pituitary mass abutting the optic chiasm with no edema and no need for urgent neurosurgical intervention. Outpatient endocrine workup demonstrated following labs: Na 135 mmol/l (ref range 135 - 145), afternoon cortisol 9.3 mcg/dl (ref range 5.0 - 23.0), ACTH 19 pg/ml (ref range 7.2-63), GH 3.8 ng/ml (ref range <=7.1), Prolactin 16.0 ng/ml (ref range 4.8 - 23.3). Due to persistent headaches, she was taking high doses of Naproxen, which resulted in nausea and vomiting, and led to another ED visit. At this time, she was found to have Na 117 mmol/l, Serum osmolality 246 mOsm/kg (re range 285–295), Urine osmolality 554 mOsm/kg (ref range 40 - 1,400), Urine Na 146 mmol/L. TSH was 0.16 mIU/ml (ref range 0.27 - 4.20) and free T4 was 0.49 ng/dl (ref range 0.80 - 1.90). Endocrine was consulted and the pathogenesis for hyponatremia was thought to be multifactorial including central adrenal insufficiency masked by central hypothyroidism. Her cortisol levels as detailed above were done early afternoon and could not exclude at least some degree of central adrenal insufficiency. Additionally, hypothyroid state can significantly decrease metabolism of cortisol thus preventing acute drop in cortisol levels. She also seemed to have concomitant syndrome of inappropriate antidiuretic hormone secretion (SIADH), driven by both the pituitary tumor as well as nausea and vomiting. On top of that for her severe progressive headaches she was treated with non-steroidal anti-inflammatory agents and tramadol, both known to associate with hyponatremia. She was started on intravenous hydrocortisone, and subsequently oral levothyroxine. She had improvement in her sodium levels and did not require Tolvaptan. She was discharged on hydrocortisone and levothyroxine with outpatient endocrine and neurosurgery follow up. She is currently awaiting neurosurgical intervention. Discussion Secondary adrenal insufficiency is more common than primary adrenal insufficiency. Establishing the diagnosis of secondary adrenal insufficiency is challenging as it is not typically associated with classical signs and symptoms of adrenal insufficiency. Clinical manifestations tend to be more indolent as they result from glucocorticoid deficiency only and there is preservation of the aldosterone and adrenal androgen axis. What makes our patient interesting is the several factors as mentioned above which contributed to her severe hyponatremia. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

PSAT001 A Case of Ectopic Cushing's Syndrome Complicated by COVID-19 Infection

Abstract Background Ectopic Cushing's syndrome is associated with high morbidity and mortality rates and patients can rapidly decline if not intervened on earlier. We report a case of Ectopic Cushing's syndrome and highlight the challenges that were encountered in managing this patient who subsequently developed Covid-19 infection during hospitalization. Clinical Case 61-year-old female with history of non-insulin dependent diabetes presented with increased confusion, elevated blood sugars and persistent hypokalemia. She was hypertensive, with exam findings of facial plethora, coarse chin hair growth, central adiposity with thin extremities. During evaluation Potassium was 2. 0 mmol/l (ref range 3.5-5), Cortisol 101.7 mcg/dl (AM ref range 6.2-19.4), ACTH 365 pg/ml (ref range 6-50), plasma renin activity of 1. 06 ng/ml/hr (ref range 0.25 - 5.82), and Aldosterone level of <1 ng/dl (supine ref range 3-16). CT abdomen/pelvis imaging revealed a 4.4×3.1 cm right pulmonary mass concerning for malignancy, two hepatic lesions suspicious for metastases and bilateral adrenal gland thickening with focal nodularity. Biopsy of the lung mass demonstrated a Grade I well differentiated neuroendocrine tumor. Unfortunately, ACTH staining was not performed on the biopsy specimen, but suspicion for ectopic hypercortisolemia remained high given her clinical presentation, resistant hypokalemia and neuroendocrine tumor. Gallium Dototate scan revealed increased uptake in the right lung infra-hilar mass and bilateral adrenal glands with decreased uptake in the liver lesions. Ketoconazole and Metyrapone were initiated along with Spironolactone and potassium supplements. She was thought to be a poor candidate for thoracic surgery and was seen by radiation oncology who recommended stereotactic body radiation therapy (SBRT) to the right lung lesion with IR guided bland embolization of the liver lesions. While awaiting further intervention, she decompensated developing hypoxic respiratory failure with high oxygen requirements and was found to have Covid-19 infection. She received convalescent plasma and Remdesevir. After much discussion, despite her endogenous hypercortisolemia, patient was given IV steroids per infectious disease and pulmonology recommendations. She continued to decline requiring intubation. Intravenous Etomidate infusion was started to decrease cortisol production. Despite many efforts, her hospital course was complicated by an upper GI bleed, acute L1-L3 fractures and significant hyperkalemia requiring hemodialysis. Family declined further intervention and withdrew treatment, shortly after which patient passed away. Discussion Ectopic cushing's disease may be associated with fatal progression of Covid-19 pneumonia and respiratory failure requiring emergent intervention. Due to endogenous hypercortisolemia, immune response may be blunted, and patients infected with Covid-19 infection may lack the typical clinical presentation and cytokine storm. Role of exogenous steroids in patients with Covid-19 infection with pre-existing endogenous hypercortisolemia is not clear with the concern being the resulting severe metabolic sequelae which may lead to adverse outcomes. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

SAP DEFICIENCY PRESENTING IN A CHILD WITH RECURRENT DIFFUSE LARGE B CELL LYMPHOMA

<h3>Introduction</h3> SLAM–associating protein deficiency (SAP deficiency), also known as X-linked lymphoproliferative disease (XLPD Type 1), is an inborn error of immunity caused by a hemizygous variant in the <i>SH2D1A</i> gene, which encodes this protein. SAP is essential for immunity to Epstein Barr Virus (EBV) with deficiency leading to fulminant EBV infection, hemophagocytic lymphohistiocytosis (HLH) and B-cell lymphomas. Herein, we describe a child who presented with recurrent B cell lymphoma and was determined to have SAP deficiency. <h3>Case Description</h3> The patient is a 7 yo previously healthy male who presented with throat pain, enlarged tonsils and cervical lymphadenopathy. He failed multiple courses of antibiotics, and tonsillar incision and drainage was ineffective. Tonsillar biopsy showed mature large B-cell lymphoma, stage II. He responded to chemotherapy, but after 3 months off therapy had relapse of disease with a tonsillar mass, confirmed by biopsy. On further work-up, testing showing very low SAP expression in lymphocytes: %SAP expressed in CD8+ Tcells 1% (ref range >62%), CD8- T cells 0% (ref range >64%), CD56 NK cells 0% (ref range >55%). XIAP expression in lymphocytes was normal. This was consistent with XLPD Type 1 or SAP deficiency. <h3>Conclusion</h3> Patients with SAP may present in infancy or in childhood with clinical presentation derived by an increased susceptibility to EBV. However, the phenotype is variable making recognition challenging without fulminant EBV infection, HLH or hypogammaglobulinemia. Immunologists should have a high suspicion for SAP deficiency in patients with recurrent lymphomas as diagnosis changes management with hematopoietic stem cell transplant leading to cure.