Foster, Trenton R.

Introduction Previous studies have demonstrated that C 11 choline positron emission tomography/computed tomography (Choline-PET/CT) can localize abnormal parathyroid glands in the reoperative setting. This study assesses a large volume of patients with primary hyperparathyroidism (1HPT) who underwent Choline-PET/CT to confirm its utility in the setting of negative or equivocal conventional imaging. Methods All patients who underwent Choline-PET/CT for evaluation of 1HPT from July 2017 to July 2024 at a single institution were reviewed. Inclusion criteria were patients who underwent parathyroidectomy and had lab testing to assess for cure (defined as >50% drop from baseline PTH and into normal range, or resolution of hypercalcemia at follow-up). Sensitivity, positive predictive value (PPV), false negative rate (FNR), and accuracy were compared to conventional imaging (neck ultrasound, parathyroid scan, and parathyroid four-dimensional CT (4D-CT)). Subgroup analysis was conducted comparing sensitivity of modalities among index operations and separately in reoperations. Results 84 patients were included for analysis. 61 failed to localize on at least one conventional modality, and 15 failed to localize on all conventional studies. 67 patients (80%) achieved cure, of which 53 were reoperations. Choline-PET/CT outperformed conventional modalities across sensitivity, PPV, FNR, and accuracy. Choline-PET/CT also outperformed conventional modalities when comparing sensitivity in both subgroups. Conclusion C 11 choline-PET/CT is a valuable imaging modality in the reoperative setting and demonstrates utility for index operations. It provides localization when other modalities fail and allows for a high surgical cure rate. Further investigation into its utility as a primary imaging modality is warranted.

Abstract Disclosure: P. Hopmann: None. S. Lund: None. T. Foster: None. B. Dy: None. T. McKenzie: None. G. Johnson: None. R.A. Wermers: None. M. Lyden: None. Background: Previous studies have demonstrated that C11 choline positron emission tomography/computed tomography (Choline-PET/CT) can localize abnormal parathyroid glands in the re-operative setting. This study assesses a large volume of patients with primary hyperparathyroidism (1HPT) who underwent Choline-PET/CT to confirm its utility in the setting of negative or equivocal conventional imaging. Methods: All patients who underwent Choline-PET/CT for evaluation of 1HPT from July 2017 to July 2024 at a single institution were reviewed. Inclusion criteria were patients who underwent parathyroidectomy and had lab testing to assess for cure (defined as >50% drop from baseline PTH and into normal range, or resolution of hypercalcemia at follow-up). Sensitivity, positive predictive value (PPV), false negative rate (FNR), and accuracy were compared to conventional imaging (neck ultrasound, parathyroid scan, and parathyroid four-dimensional CT (4D-CT)). Subgroup analysis was conducted comparing sensitivity of modalities among index operations, and separately in re-operations. Results: 176 patients were identified. 85 underwent parathyroidectomy, 1 patient was excluded due to lacking data to evaluate for cure. Of 91 patients who did not undergo parathyroidectomy, 45 were non-localizing on all imaging, and 46 had positive Choline-PET/CT findings but opted against surgery due to mild disease or prohibitive re-operative risk. Of the included 84 parathyroidectomy patients, 61 failed to localize on at least one conventional modality, and 15 failed to localize on all conventional studies. 67 patients (80%) achieved cure, of whom 53 were re-operations (range of 1-4 prior operations, average 1.5). Choline-PET/CT outperformed conventional modalities across sensitivity, PPV, FNR, and accuracy. Among index operations, Choline-PET/CT had significantly higher sensitivity than conventional modalities (100% vs 27% for ultrasound, 30% for parathyroid scan, 29% for 4D-CT; p values ≤0.01). This was also true in re-operations (95% for Choline-PET/CT vs 13% for ultrasound, 30% for parathyroid scan, 32% for 4D-CT; p values <0.01). Conclusion: C11 choline-PET/CT is a valuable imaging modality in the re-operative setting and demonstrates utility for index operations. It provides localization when other modalities fail and allows for a high surgical cure rate. Further investigation into its utility as a primary imaging modality is warranted. Presentation: Monday, July 14, 2025

Abstract Context Patients with mild autonomous cortisol secretion (MACS) can develop adrenal insufficiency after unilateral adrenalectomy. Objective This work aimed to determine the prevalence, duration, and predictors of adrenal insufficiency, and compare postoperative basal cortisol and cosyntropin stimulation test (CST). Methods In this multicenter retrospective study of patients with MACS, adrenal insufficiency was diagnosed when postoperative basal cortisol was less than 10 µg/dL and/or CST < 18 µg/dL. The results were concordant when both tests met cutoffs. Biochemical (BSS) and clinical severity scores (CSS) were calculated. Results Among 281 patients with MACS (80% women), postoperative adrenal insufficiency was diagnosed in 153 (54.5%) patients. Adrenal insufficiency inversely correlated with age (odds ratio [OR] 0.67 per 10 years; 95% CI, 0.53-0.84). Low basal cortisol and CST were associated with younger age (OR 0.64 per 10 years for both) and higher BSS (OR 1.17 and 1.22, respectively). Basal cortisol and CST were discordant in 22% of patients, and the discordance rate was more common in patients with bilateral nodules (32% vs 19%; P < .001). The median time to adrenal insufficiency recovery was 3.9 months (IQR, 3-5.9 months), with longer duration associated with higher BSS and CSS: 3 months for mild, 4 to 5 months for moderate, and 12 to 14 months for severe BSS and CSS. Conclusion Approximately half of patients with MACS developed postoperative adrenal insufficiency, with 50% recovering by 3.9 months after surgery. BSS correlated with basal cortisol, CST, and duration of adrenal insufficiency. As discordant results were noted in 22%, performing both basal cortisol and CST postoperatively should be considered.

Background: Oncocytic adrenal neoplasms, defined by ≥90 % of oncocytic cells, are rare. The significance of oncocytic changes within an adrenal neoplasm remains unclear. Methods: A retrospective study of adults who underwent adrenalectomy at a large center identified pure oncocytic neoplasms on final pathology (1997-2022). Neoplasms were categorized based on Lin-Weiss-Bisceglia system as malignant, benign, or of uncertain malignant potential. Analysis was performed using Fisher exact, Kruskal-Wallis tests, and Kaplan-Meier analysis. Results: Among a total of 33 patients, 24% had benign, 36% malignant, and 39% neoplasm of uncertain malignant potential. None of the benign neoplasms recurred, while 50% of the malignant neoplasms recurred (median of 40 months). Two of 13 neoplasms initially thought to be of uncertain malignant potential recurred as distant metastatic adrenocortical carcinoma at 11 and 25 months, over a median follow-up duration of 31 months. Ki67% was available for 20 patients: median (IQR) Ki67% was 5 (1, 5) for benign, 10 (6, 15) for malignant, and 6.5 (5, 10) for neoplasms of uncertain behavior, P = 0.05. Recurred neoplasms had higher Ki67% at initial resection compared to cases that did not recur. Conclusion: While oncocytic adrenal neoplasms are rare, a significant proportion are malignant or have malignant potential. Judicious follow-up is required for oncocytic adrenal neoplasms of uncertain malignant potential, as they can recur as metastatic adrenocortical carcinoma. Ki67% should always be obtained in cases of malignancy or uncertain malignant potential as it can predict recurrence. Larger studies are needed to evaluate the appropriate follow-up protocols for these neoplasms.

Abstract Disclosure: O. Hamidi: Advisory Board Member; Self; Corcept, Neurocrine Biosciences, Amryt Pharma, Recordati Rare Diseases, Lantheus, Xeris. B.H. Salama: None. P. Dogra: None. A.P. Dackiw: None. F. Nwariaku: None. A. Islam: None. A. Mehta: None. S.C. Oltmann: None. S. Mirfakhraee: None. T. McKenzie: None. T.R. Foster: None. M. Lyden: None. B.M. Dy: None. I. Bancos: None. Introduction: Patients with mild autonomous cortisol secretion (MACS) are at risk for adrenal insufficiency (AI) after unilateral adrenalectomy. We aimed to determine the prevalence, predictors, and duration of AI after unilateral adrenalectomy for MACS, and to compare baseline and peak cortisol post cosyntropin stimulation test (CST) in diagnosing AI. Methods: We conducted a dual-center retrospective cohort study of patients with MACS who underwent unilateral adrenalectomy and were evaluated with postoperative cosyntropin stimulation test (CST). AI was diagnosed when postoperative morning cortisol was <10μg/dL and/or CST peak cortisol was <18μg/dL. Baseline and CST peak cortisol levels were considered concordant when both met corresponding cut-offs. Biochemical (BSS) and clinical (CSS) severity scores for hypercortisolism were calculated. Results: In 100 adults with MACS (77% women, median age 56 years, interquartile range [IQR] 48-63), median adenoma size was 2.8 cm (IQR, 2.2-3.7), and 25 (25%) had bilateral nodules. Median BSS was 3 (IQR, 2-5) and median CSS was 4 (IQR, 2-8). After adrenalectomy, AI was diagnosed in 56 (56%) patients. AI was associated with higher BSS, larger tumor size, but not age, sex, BMI, tumor laterality. Baseline and CST peak cortisol levels were concordant in 76% of cases. In 14% of cases morning cortisol was <10μg/dL but CST peak cortisol was ≥18μg/dL, and in 10% of cases morning cortisol was ≥10μg/dL, but CST peak cortisol was <18μg/dL. On a multivariable analysis that included age, sex, BMI, BSS, laterality, and tumor size, only higher BSS (odd ratio [OR] = 1.6 per 1 point) was associated with postoperative baseline cortisol <10μg/dL (P<0.05 for all). Independent predictors of CST peak cortisol <18μg/dL were BSS (OR 1.5 per 1 point) and unilateral adenoma (OR 3.7). During a median postoperative follow up of 13 months, 33 (59%) patients recovered from AI. Median time to recovery was 6.0 months, with AI recovery in 28% of patients by 2 months, 42% by 3 months, 53% by 6 months, and 64% by 12 months. Conclusions: Prevalence of postoperative AI in MACS was 56%. Only 76% of patients had concordant baseline and CST peak cortisol, with peak CST cortisol being more commonly abnormal in patients treated for unilateral MACS. Patients with larger adenomas and higher BSS were at higher risk for AI. Patients with MACS should be counseled about the risk and duration of AI after adrenalectomy. Presentation: 6/3/2024

Abstract Disclosure: B. Bahrani Fard: None. N. Nikravangolsefid: None. J. Maroun: None. A. Cross: None. T. Foster: None. T. McKenzie: None. W. Young Jr: None. B.M. Dy: None. M. Lyden: None. I. Bancos: None. Background: Giant pheochromocytomas (PHEO), defined based on size > 10 cm, are rare. Data on clinical presentation, management, and prognosis of giant PHEOs are scarce. Objectives: to determine prevalence of giant PHEO and compare presentation, management, and outcomes of patients with giant vs non-giant PHEOs. Methods: We conducted a single-center retrospective cohort study of consecutive patients with giant PHEO and randomly chosen patients with non-giant PHEO (referents) at 6:1 ratio, evaluated between 2000-2023. All variables were extracted from the electronic medical record. Results: Of 828 patients with PHEO evaluated between 2000 and 2023, 31 (3.7%) had giant PHEO (median size 12 cm, IQR 10.0-13.5). In comparison to referents (n=186, median size 4 cm, IQR, 2.9-5.0), patients with giant PHEO were similar in age (median age 53 vs 55 years, P=.55), more frequently discovered based on symptoms (52% vs 32%, P=.04), and less likely to be bilateral (3% vs 12%, P=.31). Genetic testing was performed in 103 (48%) of patients, without group differences, however, patients with giant PHEO were less likely to have an associated germline mutation detected (7% vs 47%, P=.004). Patients with giant PHEO had more symptoms of catecholamine excess (median of 2 vs 1, P=.04) and presented with a higher prevalence of severe metanephrine excess >10 times above upper normal range (76% vs 30%, P<.0001). Adrenalectomy was performed in 94% of patients with giant PHEOs and in 100% referents, with higher rates of open adrenalectomy in giant PHEO (86% vs 14%, P<.0001). In addition to preoperative alpha-adrenergic blockade (89%), metyrosine was used in 14 (7%) patients, mostly in patients with giant PHEO (26% vs 3%, P<.0001). Patients with giant PHEO had a longer hospital length of stay (laparoscopic: median 5 vs 2 days, P<.0001; open: median 6 vs 5 days, P=.24), and a higher complication rate (31% vs 10%, P=.006).Median follow up was 3 years (IQR 1-8) years, similar in patients and referents. Metastases developed at a much higher rate in patients with giant PHEOs (45% vs 4% in referents, P<.0001). Disease specific mortality was 7% in patients with giant PHEOs and 0% in referents. Conclusion: Patients with giant PHEO were more symptomatic, had a higher degree of catecholamine excess, and a higher rate of perioperative complications. Almost half of patients with giant PHEO developed metastases, warranting a close follow-up. Presentation: 6/2/2024

Abstract Context Data on giant pheochromocytomas (PHEOs), defined based on size 10 cm or greater, are scarce. Objective This work aimed to compare presentation, management, and outcomes of patients with giant vs non–giant PHEOs. Methods A retrospective cohort study was conducted in a referral center from 2000 to 2023. Consecutive patients with giant PHEOs and randomly chosen patients with non–giant PHEO (referents) were studied at a 1:6 ratio. Outcomes included perioperative complications, metastases, and mortality. Results Of 828 patients with PHEOs, 31 (3.7%) had giant PHEO (median size 12 cm, interquartile range [IQR] 10.0-13.5 cm). In comparison to referents (n = 186, median size 4 cm, IQR, 2.9-5.0 cm), patients with giant PHEO had more symptoms of catecholamine excess (median of 2 vs 1; P = .04) and presented with a higher prevalence of severe catecholamine excess (76% vs 30%; P < .0001). Adrenalectomy was performed in 94% of patients with giant PHEOs and 100% of referents. In addition to preoperative α-adrenergic blockade (89%), metyrosine was used in 14 (7%) patients, mostly in patients with giant PHEOs (26% vs 3%; P < .0001). Patients with giant PHEOs had a higher perioperative complication rate (31% vs 10%; P = .004). During a median follow-up of 3 years, metastases developed at a higher rate in patients with giant PHEOs (45% vs 4% in referents; P < .0001). Disease-specific mortality was 7% in patients with giant PHEOs and 0% in referents (P = .02). Conclusion Patients with giant PHEOs compared to referents were more symptomatic, had a higher degree of catecholamine excess, and had a higher rate of perioperative complications. Almost half of patients with giant PHEOs developed metastases, warranting close follow-up.

Abstract Adrenal cysts are a rare benign adrenal pathology. Although the majority of adrenal cysts are asymptomatic, large cysts may present with debilitating symptoms of mass effect. Surgical adrenalectomy or cyst fenestration has been the primary mode of management for such symptomatic cysts, but these interventions can be associated with excessive morbidity, particularly when considered in the context of benign disease. Here, we present a case of a 34-year-old female with a longstanding, growing, benign left adrenal cyst associated with nonspecific abdominal symptoms. After multidisciplinary discussion, the patient was managed with primary ultrasound/fluoroscopic guided percutaneous sclerotherapy of her adrenal cyst. This technique achieved complete cyst resolution that was durable on 7-month follow-up and was associated with significant improvement of the patient's symptoms. This case illustrates the potential for primary percutaneous sclerotherapy for primary management of benign adrenal cysts.

Background: Despite numerous potential benefits of outpatient surgery, there is currently a lack of national benchmarking data available for hospitals and surgeons to compare their own outcomes as they transition toward outpatient surgery. Materials and methods: Patients who underwent 14 common general surgery operations from 2016 to 2020 were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Operations were selected based on frequency and the ability to be performed both inpatient and outpatient. Postoperative complications and readmissions were compared between patients who underwent inpatient vs outpatient surgery. After adjusting for patient comorbidities, multivariable models assessed the effect of patient characteristics on the odds of experiencing postoperative complications. A separate multi-institutional study of 21 affiliated hospitals assessed practice variation. Results: In 13 of the 14 studied procedures, complications were lower for patients who were selected for outpatient surgery (all P<0.01); minimally invasive (MIS) adrenalectomy showed no difference (P=0.61). Multivariable analysis confirmed these findings; the odds of experiencing any adverse events were lower following outpatient surgery in all operations but MIS adrenalectomy (OR 0.97; 95% CI: 0.47–2.02). Analysis of institutional practices demonstrated variation in the rate of outpatient surgery in certain breast, endocrine, and hernia repair operations. Conclusions: Institutional practice patterns may explain the national variation in the rate of outpatient surgery. While the present data does not support the adoption of outpatient surgery to less optimal candidates, addressing unexplained practice variations could result in improved utilization of outpatient surgery.

Abstract Disclosure: M. Chinthapalli: None. P. Dogra: None. R. Sandooja: None. L. Rahimi: None. N.M. Iniguez Ariza: None. T. Foster: None. I. Bancos: None. Introduction: Adrenal glands are susceptible to hemorrhage due to their unique vasculature and physiological stress response. Scarce data are available on the presentation, etiology, and outcomes of adrenal hemorrhage (AH). Objective: To describe the presentation, etiological associations, and outcomes of patients with unilateral and bilateral AH. Methods: Single-center retrospective longitudinal study of consecutive patients reported to have AH on imaging performed between January 1st 2017-December 31st 2021. Clinical, baseline and follow up imaging, and laboratory data were reviewed. Subgroup analysis was performed based on the laterality (unilateral vs. bilateral) of AH. Results: Of 454 patients with AH (median age 62 years (IQR 50-70), 160 (35%) women), 383 (85%) had unilateral AH, 60 (13%) presented with synchronous bilateral AH, and 9 (2%) had unilateral AH followed by contralateral AH at a later time (metachronous bilateral AH). Only 93 (20%) patients had an evaluation by an endocrinologist. AH was discovered incidentally in 190 (42%) patients, and during evaluation for abdominal or back pain in 133 (29%), trauma in 104 (23%), sepsis in 19 (4%), and adrenal insufficiency in 8 (2%). Primary etiology of AH was a post-procedural complication in 154 (34%), trauma in 126 (28%), coagulopathy in 54 (12%), anticoagulant or antiplatelet therapy in 52 (12%), adrenal neoplasm in 29 (6%) and sepsis in 20 (4%). Metastasis (15, 50%) represented the most common adrenal neoplasm associated with AH. In 208 (46%) patients, diagnosis of AH occurred in the hospital setting, and in 246 (54%) during an outpatient evaluation. In the 393 patients with available baseline imaging, the median size of AH was 3.1 cm (IQR 2.2-4.0). During a median imaging follow-up of 6 months (IQR 3-12), AH reduced in size with a median decrease of -2.6 cm (IQR -1.8 to -3.7) on the right and -2.0 cm (IQR -1.0 to -4.8) on the left. Compared to patients with unilateral AH, those with bilateral AH were more likely to be diagnosed in the hospital setting (61 vs. 43%, P=0.006), have an underlying coagulopathy (50 vs. 4%, P&lt;0.0001), or sepsis (13 vs. 3%, P&lt;0.0001), be on anticoagulant or antiplatelet therapy (48 vs. 21%, P&lt;0.0001), develop primary adrenal insufficiency (61 vs. 0%, P&lt;0.0001) and have larger baseline AH size (4 cm vs. left 2.7 and right 3.1 cm, P=0.0002), but a similar rate of resolution. Conclusions: AH frequently presents as unilateral hemorrhage and can occur secondary to various etiologies, with trauma and postprocedural complication being the most common. Association with an underlying adrenal mass is uncommon, seen only in 6%. Bilateral AH carries a high risk for primary adrenal insufficiency and is more likely to occur in hospitalized patients, possibly due to an increased prevalence of underlying coagulopathy, sepsis and need for anticoagulation or antiplatelet therapy. Presentation: Friday, June 16, 2023