Surveillance Imaging Research Articles

Imaging in Diagnosis and Active Surveillance for Prostate Cancer: A Review.

Active surveillance (AS) has become an increasingly important option for managing low-risk and select intermediate-risk prostate cancer. Although imaging, particularly multiparametric magnetic resonance imaging (mpMRI), has emerged in the prebiopsy pathway for the diagnosis of prostate cancer, the role of mpMRI in patient selection for AS and the necessity of prostate biopsies during AS remain poorly defined. Despite well-founded biopsy schedules, there has been substantial investigation into whether imaging may supplant the need for prostate biopsies during AS. This review aimed to summarize the contemporary role of imaging in the diagnosis and surveillance of prostate cancer. Multiparametric MRI is the most established form of imaging in prostate cancer, with routine prebiopsy use being shown to help urologists distinguish between clinically significant and clinically insignificant disease. The visibility of these lesions on mpMRI closely correlates with their behavior, with visible disease portending a worse prognosis. Combined with other clinical data, risk calculators may better delineate patients with higher-risk disease and exclude them from undergoing AS. While current evidence suggests that mpMRI cannot replace the need for prostate biopsy during AS due to the possibility of missing higher-risk disease, the addition of prostate biomarkers may help to reduce the frequency of these biopsies. The role of prostate-specific antigen positron emission tomography/computed tomography is still emerging but has shown promising early results as an adjunct to mpMRI in initial diagnosis. Imaging in prostate cancer helps to better select patients appropriate for AS, and future studies may strengthen the predictive capabilities of risk calculators. Multiparametric MRI has been shown to be imperative to rationalizing biopsies for patients enrolled in AS. However, heterogeneity in the evidence of mpMRI during AS has suggested that further prospective studies and randomized clinical trials, particularly in homogenizing reporting standards, may reveal a more defined role in monitoring disease progression.

Abstract 4117345: Predicting Downstream Aneurysmal Degeneration Following Type A Dissection Repair With Computational Fluid Dynamics

Introduction: Acute type A aortic dissection (ATAAD) is typically treated by replacement of the ascending aorta (+/- root) and proximal arch. However, 70-85% of patients have residual distal dissection post-repair, and 20-40% require late reoperation for aneurysmal degeneration of the distal aorta (ADDA). Since an individual patient’s risk of ADDA cannot be accurately predicted, current guidelines recommend lifelong aortic surveillance imaging for all patients. Hypothesis: Computational fluid dynamics (CFD) simulations of aortic hemodynamics post-repair can accurately identify patients at late risk of ADDA. Methods: We performed CFD simulations of 50 patients following hemi-arch replacement for ATAAD. Patient-specific 3D models were generated from the aortic root to iliac bifurcation (including arch branches) from postoperative 0.6mm contrast-enhanced CT angiograms taken <1 year after index repair (Figure). Exclusion criteria were known heritable thoracic aortic disease and absence of residual dissection. The primary outcome was ADDA, defined as late growth of the distal arch/descending thoracic aorta (DTA) to a diameter ≥5.5cm. Hemodynamic simulations were run for 6 cardiac cycles on a high-performance computing cluster using HARVEY, a CFD solver implementing the lattice Boltzmann method. The primary hemodynamic metric was time-averaged wall shear stress (TAWSS) ratio between the false and true lumens. Results: ADDA developed in 22 patients (44%) at a mean of 3.2 years postoperatively. There were no significant clinical differences between those with and without ADDA (Table). The development of late aneurysm growth was significantly associated with a higher TAWSS ratio in the proximal DTA ( p <0.05, Figure). Conclusion: ADDA following hemi-arch repair for ATAAD is associated with significantly higher false lumen TAWSS as early as the first surveillance scan. CFD simulations may help clinicians risk-stratify patients years before they meet reoperation criteria.

Impact of Socioeconomic Deprivation on Care Quality and Surgical Outcomes for Early-Stage Non-Small Cell Lung Cancer in United States Veterans

Background: Socioeconomic deprivation has been associated with higher lung cancer risk and mortality in non-Veteran populations. However, the impact of socioeconomic deprivation on outcomes for non-small cell lung cancer (NSCLC) in an integrated and equal-access healthcare system, such as the Veterans Health Administration (VHA), remains unclear. Hence, we investigated the impact of area-level socioeconomic deprivation on access to care and postoperative outcomes for early-stage NSCLC in United States Veterans. Methods: We conducted a retrospective cohort study of patients with clinical stage I NSCLC receiving surgical treatment in the VHA between 1 October 2006 and 30 September 2016. A total of 9704 Veterans were included in the study and assigned an area deprivation index (ADI) score, a measure of socioeconomic deprivation incorporating multiple poverty, education, housing, and employment indicators. We used multivariable analyses to evaluate the relationship between ADI and postoperative outcomes as well as adherence to guideline-concordant care quality measures (QMs) for stage I NSCLC in the preoperative (positron emission tomography [PET] imaging, appropriate smoking management, pulmonary function testing [PFT], and timely surgery [≤12 weeks after diagnosis]) and postoperative periods (appropriate surveillance imaging, smoking management, and oncology referral). Results: Compared to Veterans with low socioeconomic deprivation (ADI ≤ 50), those residing in areas with high socioeconomic deprivation (ADI > 75) were less likely to have timely surgery (multivariable-adjusted odds ratio [aOR] 0.832, 95% confidence interval [CI] 0.732–0.945) and receive PET imaging (aOR 0.592, 95% CI 0.502–0.698) and PFT (aOR 0.816, 95% CI 0.694–0.959) prior to surgery. In the postoperative period, Veterans with high socioeconomic deprivation had an increased risk of 30-day readmission (aOR 1.380, 95% CI 1.103–1.726) and decreased odds of meeting all postoperative care QMs (aOR 0.856, 95% CI 0.750–0.978) compared to those with low socioeconomic deprivation. There was no association between ADI and overall survival (adjusted hazard ratio [aHR] 0.984, 95% CI 0.911–1.062) or cumulative incidence of cancer recurrence (aHR 1.047, 95% CI 0.930–1.179). Conclusions: Our results suggest that Veterans with high socioeconomic deprivation have suboptimal adherence to care QMs for stage I NSCLC yet do not have inferior long-term outcomes after curative-intent resection. Collectively, these findings demonstrate the efficacy of an integrated, equal-access healthcare system in mitigating disparities in lung cancer survival that are frequently present in other populations. Future VHA policies should continue to target increasing adherence to QMs and reducing postoperative readmission for socioeconomically disadvantaged Veterans with early-stage NSCLC.

EXTH-81. A RARE CASE OF RELENTLESSLY PROGRESSIVE METASTATIC PINEOCYTOMA MANAGED WITH SEQUENTIAL MULTIMODAL THERAPY

Abstract BACKGROUND Pineocytoma is a rare pineal parenchymal WHO grade 1 tumor, typically well-managed with surgical resection alone. With gross total resection (GTR), 91% 1-year and 84% 5-year survival rates have been reported. Recurrent pineocytoma is rare and optimal management in that setting is unknown, in part owing to the rarity of the condition. METHODS We report an atypical course of pineocytoma in a 58-year-old male involving metastatic disease. RESULTS A pineal mass was identified upon MRI of the brain obtained for vision changes. Patient underwent GTR, pathology was consistent with pineocytoma, WHO grade 1. Ki-67 labeling index was low at 1-2%. Despite low-grade pathology, two years later, surveillance imaging demonstrated recurrence in the pineal region and a second lesion in the right thalamus. The patient underwent gamma knife surgery (GKRS) to both lesions. Three years later, he developed three new lesions in the right cerebellum and again underwent GKRS. Subsequent surveillance imaging identified new lesions in the right cerebellum and along ventricular walls, treated with further GKRS. Nine years after initial diagnosis, focal nodular leptomeningeal metastases were discovered, along with progression at the primary tumor site. Patient was treated with GKRS to the nodular deposits followed by pembrolizumab. Further disease progression as noted despite immunotherapy. Patient was treated with 6 cycles of temozolomide chemotherapy and at further progression 3 cycles of lomustine. Upon additional progression, further radiation therapy was administered with bevacizumab to reduce risk of radiation necrosis. Patient remains on surveillance 13 years after initial diagnosis with visual changes and mild headache representing only clinical issues. CONCLUSIONS Although exceedingly rare, pineocytoma is capable of metastasizing to brain parenchyma and the leptomeninges, as demonstrated in our patient. However, our case demonstrates prolonged survival is possible even in the setting of relentlessly progressive metastatic disease with utilization of multimodality treatment.

A novel therapeutic pathway to the human cochlear nerve.

Traditional approaches to the human cochlear nerve have been impeded by its bony encasement deep inside the skull base. We present an innovative, minimally invasive, therapeutic pathway for direct access to the nerve to deliver novel regenerative therapies. Neuroanatomical studies on 10 cadaveric human temporal bones were undertaken to identify a potentially safe therapeutic pathway to the cochlear nerve. Simulations based on three-dimensional delineation of anatomical structures obtained from synchrotron phase-contrast imaging were analyzed. This enabled the identification of an approach to the nerve in the fundus of the internal auditory meatus by trephining the medial modiolar wall of the cochlea via the round window for a median depth of 1.48mm (range 1.21-1.91mm). The anatomical access was validated on 9 additional human temporal bones using radio-opaque markers and contrast injection with micro-computed tomography surveillance. We thus created an effective conduit for the delivery of therapeutic agents to the cochlear nerve.

Retroperitoneal Malakoplakia Mimicking Metastatic Disease.

Malakoplakia is a rare inflammatory granulomatous disease that can produce a tumor-like appearance in nearly any organ system. Imaging findings of malakoplakia overlap with malignancy and tissue sampling are typically required for definitive diagnosis. We present a case of a 66-year-old woman with a previous history of liver adenocarcinoma status post resection that subsequently developed an intensely FDG-avid retroperitoneal mass on surveillance imaging. CT-guided biopsy of the mass demonstrated Michaelis-Gutmann bodies, supporting the diagnosis of malakoplakia. The patient underwent antibiotic treatment with complete resolution of the mass.

A Review on Image Enhancement Using AI

Image Enhancement is an important domain in image processing, as this helps to ensure the potentiality and visibility of images. With regular increase in image production, Image enhancement comes under use as most of the image gets dull or degraded while clicking, thus it is important to develop methods for image enhancement. Image enhancement is performed by various machine learning approaches, by decompressing, denoising and decomposing images. This is variously used in the field of medical, journalism, forensic investigation, satellite imaging, photography and security and surveillance. This paper provides an overview of the importance of image enhancement and various methods to apply it on images.

The natural history of cerebral infundibula: A retrospective cohort study.

Debate exists regarding the true pathogenicity of cerebral infundibula (CI). Pre-aneurysmal lesions and benign anatomical variants have both been proposed. In this study, we present the largest single cohort series on the natural history of CI. Retrospective review of prospective surveillance of 420 CI was undertaken in a single tertiary cerebrovascular centre. All CI diagnosed by a neuroradiologist, diagnosed on either a Magnetic resonance angiography (MRA), Computed tomography angiography (CTA) or Digital subtraction angiography (DSA) were eligible for inclusion. Imaging and demographic characteristics were recorded at baseline. CI growth and aneurysm transformation were the outcomes of interest. Groupwise comparison was conducted via Fischer exact testing. Kaplan Meir curves and Cox proportional hazard ratios were used to assess variables of interest with respect to time on surveillance. 402 patients with 420 CI were surveyed over 2418 infundibula-years. Eleven CI (2.62%) grew on surveillance, and three (0.7%) transformed into aneurysms. Median time to growth was 85 months (36-263) and median time to aneurysm transformation was 112 months (96-142). Of the CI that grew, male sex and CI >2 mm at diagnosis were significant predictors of growth (all p<0.05). Of the CI that grew in surveillance, 2/11 (18.2%) transformed into aneurysms (p=0.001). Aneurysm transformation occurred at a rate of 1.27 per 1000 infundibula years. CI growth on surveillance (p= 0.00016) and size at diagnosis (p=0.038) remained significant predictors of aneurysm transformation on Kaplan Meir curves. The transformation of a CI to an aneurysm occurs at a low rate. A history of growth on surveillance imaging represents significant risk for aneurysm transformation.

Paraconduit hiatus hernia after esophageal cancer surgery: incidence, risk factors, and management.

In parallel with improved operative and oncologic outcomes for esophageal cancer, paraconduit hiatus hernia (PHH) is an increasingly recognized entity, both in the early postoperative phase and in long-term follow-up. The aim of this study was to assess the incidence of and risk factors for PHH, and to describe management approaches in a tertiary referral center. All patients undergoing surgery with curative intent for esophageal cancer from 2008 to 2022 at a single center were included. Early PHH was defined as occurring within threemonths of index surgery, with all other cases defined as late PHH. Surveillance computed tomography scans were undertaken among all disease-free patients to 5years postoperatively. Kaplan Meier and Cox proportional hazards regression models were used to determine independent risk factors for PHH. Overall, 897 patients were studied. Totally, 62 patients (6.9%) developed PHH during follow-up. The 5-year survival-adjusted incidence of PHH was 9.7%. PHH was an asymptomatic radiologic finding in 45.5% of early and 84.3% of late cases (P =0.070). Surgical intervention was required in 16 cases (25.8%), more commonly following early (63.6%) as compared with late PHH (17.6%, P < 0.01). Younger age (P < 0.039), initial transhiatal operative approach (P < 0.006) and extended resection of the crura (P < 0.001) were independently associated with increased risk of PHH on multivariable analysis. PHH was identified in almost 1 in 10 patients using surveillance imaging in long-term follow-up, independently associated with the transhiatal surgical approach and resection of crura, which raises consideration of prevention strategies. Surgical intervention is often required for patients with PHH presenting early after surgery, but many patients presenting with late PHH may be managed expectantly.

YOLO-DHGC: Small Object Detection Using Two-Stream Structure with Dense Connections.

Small object detection, which is frequently applied in defect detection, medical imaging, and security surveillance, often suffers from low accuracy due to limited feature information and blurred details. This paper proposes a small object detection method named YOLO-DHGC, which employs a two-stream structure with dense connections. Firstly, a novel backbone network, DenseHRNet, is introduced. It innovatively combines a dense connection mechanism with high-resolution feature map branches, effectively enhancing feature reuse and cross-layer fusion, thereby obtaining high-level semantic information from the image. Secondly, a two-stream structure based on an edge-gated branch is designed. It uses higher-level information from the regular detection stream to eliminate irrelevant interference remaining in the early processing stages of the edge-gated stream, allowing it to focus on processing information related to shape boundaries and accurately capture the morphological features of small objects. To assess the effectiveness of the proposed YOLO-DHGC method, we conducted experiments on several public datasets and a self-constructed dataset. Exceptionally, a defect detection accuracy of 96.3% was achieved on the Market-PCB public dataset, demonstrating the effectiveness of our method in detecting small object defects for industrial applications.

Cardiovascular effects of BRAF and MEK inhibitors in patients with melanoma: a prospective study incorporating risk scores, cardiac biomarkers and cardiovascular magnetic resonance imaging

Abstract Background BRAF and MEK inhibitors have revolutionised treatment for patients with BRAF-mutated melanoma. Unfortunately, they are associated with cardiovascular adverse effects including hypertension and cancer-therapy related cardiac dysfunction (CTRCD). The ‘real world’ incidence and risk factors for these adverse effects are poorly described. Purpose To characterise the incidence and risk factors for BRAF and MEK inhibitor-associated hypertension and CTRCD in a prospective ‘real world’ setting. Methods Prospective, observational, cohort study of patients with melanoma treated with BRAF and MEK inhibitors at a regional cancer hospital network (March 2021 - May 2023). Comprehensive assessment was performed at baseline, 4, 12 and 24 weeks following start of treatment, including home and clinic blood pressure assessment, serial echocardiography, stress-perfusion cardiovascular magnetic resonance imaging (CMR) and humoral biomarkers (Figure 1). CTRCD was defined as mild, moderate or severe in line with International Cardio-Oncology Society (IC-OS) definitions. Hypertension was defined as 7 day average home blood pressure of ≥135/85 mmHg or the initiation or escalation of anti-hypertensive therapy. Baseline cardiotoxicity risk stratification was performed using the ESC Cardio-Oncology guideline-recommended tool. Results 61 participants were enrolled. 48% developed BRAF/MEK inhibitor associated hypertension. 46% of participants developed CTRCD and, of these, 24 (86%) were classified as mild, 3 (11%) moderate and 1 (3%) severe. Left ventricular ejection fraction (LVEF) during follow up is shown in Figure 2. All participants with moderate and severe CTRCD also had BRAF/MEK inhibitor associated hypertension. After stratification with the baseline risk assessment tool, no patient in the ‘low risk’ group developed moderate or severe CTRCD. Baseline elevated NT-proBNP (&amp;gt;125pg/mL), history of left ventricular systolic dysfunction and atrial fibrillation were associated with the development of CTRCD. 20 participants underwent stress perfusion CMR at baseline, 4 and 24 weeks. 25% had a drop in LVEF to &amp;lt;50% but only 5% had a co-existing LVEF ≥10% from baseline to fulfil criteria for the diagnosis of moderate CTRCD. Conclusion BRAF and MEK inhibitor-associated hypertension and CTRCD is common, with a higher incidence in this ‘real world’ prospective cohort than observed in clinical trials. The majority of CTRCD was ‘mild’ and the long term sequalae of this remains unknown. No patients considered to be at low baseline risk for CTRCD using the ESC-recommended risk stratification tool developed moderate or severe CTRCD. These findings support the use of routine blood pressure surveillance in this group as well as baseline risk stratification to guide appropriate imaging surveillance of cardiac function.Figure 1.Schedule of study visitsFigure 2.LV function/CTRCD over time

Detection, Patterns, and Outcomes of Recurrent HPV-Positive Oropharyngeal Squamous Cell Carcinoma

Recurrent human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) is a relatively rare but serious disease with little empirical data. Previous works have studied patterns of recurrence in HPV-positive OPSCC, but only one has studied truly recurrent disease as opposed to persistent disease, and no work systematically analyzed posttreatment surveillance imaging strategies and how recurrences were detected. To refine the understanding of HPV-positive OPSCC recurrence and inform optimal imaging surveillance strategies. This retrospective cohort study involved electronic medical record review at a tertiary care hospital. Patients treated for OPSCC from 2012 to 2019 were extracted, and patients diagnosed with HPV-positive OPSCC were identified. Data were analyzed from December 2022 to May 2023. Percentage of patients with a true recurrence, location of recurrence, time of recurrence detection, and method of recurrence detection. Recurrence was demonstrated with a scan after an imaging-established disease-free state 3 to 6 months posttreatment. Of the 367 patients with HPV-positive OPSCC (mean [SD] age, 60.6 [9.2] years; 310 [84.5%] male), 37 (10.1%) experienced true disease recurrence. Median (IQR) follow-up time of the cohort was 3.6 years (8.5-88 months), defined as time from diagnosis to death or last contact. Within the true recurrence cohort, 21 patients (56.8%) experienced local, regional, or local and regional recurrence (LRR); 15 (40.5%) experienced distant metastasis (DM); and 1 (2.7%) experienced both LRR and DM. The mean (SD) time for detecting LRR was 2.46 (1.94) years and was considerably longer compared to the 1.89 (0.87) years for detecting DM (difference, 0.57 [95% CI, -0.29 to 1.02] years). The majority of patients identified their recurrence through symptom changes (31 [81.1%]) rather than through surveillance imaging (3 [8.1%]). In this cohort study, 10.1% of patients experienced true HPV-positive OPSCC disease recurrence, with most incidences of DM occurring in the lung and brain. Disease recurrence was identified primarily through symptomatic change, suggesting that further research may be needed to understand the optimal surveillance strategies after definitive treatment.

Surveillance Imaging and GAAD/GALAD Scores for Detection of Hepatocellular Carcinoma in Patients with Chronic Hepatitis.

Early detection of hepatocellular carcinoma (HCC) is crucial for improving survival in patients with chronic hepatitis. The GALAD algorithm combines gender (biological sex), age, α-fetoprotein (AFP), Lens culinaris agglutinin-reactive fraction of AFP (AFP-L3), and protein induced by vitamin K absence or antagonist-II (PIVKA-II) for HCC detection. Similarly, the GAAD algorithm incorporates gender (biological sex), age, AFP, and PIVKA-II. This study aimed to assess the clinical utility of AFP-L3 in the GALAD algorithm and its potential synergies with ultrasound. We compared the clinical performance of GALAD with GAAD; AFP; AFP-L3; and PIVKA-II, with or without ultrasound, in Taiwanese adults. A total of 439 serum samples were analyzed using a Cobas® e 601 analyzer (healthy controls, n = 200; chronic liver disease controls, n = 177; HCC cases, n = 62). Performance was assessed through receiver operating characteristic curve analyses to calculate the area under the curve. The area under the curve for differentiating early-stage HCC from patients with chronic liver disease was optimal for PIVKA-II (84.9%), GAAD (79.8%), and GALAD (79.4%), with slightly improved performance for detecting all-stage HCC. Clinical performance was unaffected by disease stage or etiology. Sensitivity for early-stage HCC was highest for GAAD (57.6%) and GALAD (57.6%). Sensitivity for each strategy was further enhanced when combined with ultrasound, regardless of disease stage or etiology (P < 0.01). These findings indicate that the role of AFP-L3 in the GALAD algorithm is minimal, supporting the use of GAAD for HCC detection. A combination of GAAD, GALAD, or PIVKA-II with ultrasound may improve diagnostic efficiency compared with recommended strategies.

Successful Pedal Bypass in a Patient With Pseudoxanthoma Elasticum.

Pseudoxanthoma elasticum (PXE) is a rare metabolic disease, causing calcification in the arterial media layer and further peripheral artery disease (PAD). A high rate of failure has been reported after endovascular and open surgical management of PAD among patients with PXE. Critical limb ischemia (CLI) rarely develops in PXE, and there are only few reports of its treatment. We present a case report of a 57year-old female diagnosed with pseudoxanthoma elasticum (PXE). She presented with critical limb ischemia (CLI) and was successfully treated with pedal bypass using the great saphenous vein. Despite obtaining suboptimal outcomes through the initial approach of percutaneous transluminal angioplasty to treat critical limb ischemia, the subsequent bypass operation proved to be a success. At the first follow-up appointment at 1month, the patient was asymptomatic and the ulceration had almost healed. The patient underwent an ultrasound examination at 3, 6, 12, and 24months after discharge, and the surveillance was uncomplicated. With a clear indication for surgery, limb-threatening ischemia can be successfully treated with distal bypass, if necessary, in patients with PXE similarly to atherosclerotic PADs. Appropriate diagnostic and surveillance imaging and the utilization of a multidisciplinary team are key components for effective management of PAD in patients with PXE.

Baseline Diameter Does Not Predict Growth Rate in a Presurgical Ascending Thoracic Aortic Aneurysm Population.

Patients with ascending thoracic aortic aneurysm are recommended to undergo routine imaging surveillance. Although maximal diameter is the primary metric of disease severity, recent American College of Cardiology/American Heart Association guidelines emphasize the importance of aortic growth in determining surgical candidacy and risk. As diameter increases, it is assumed that aortic growth rate accelerates because of increased wall tension; however, this relationship is poorly studied. We aim to investigate the relationship between ascending thoracic aortic aneurysm diameter and growth rate using vascular deformation mapping, a validated technique for 3-dimensional growth mapping with submillimeter accuracy. We retrospectively identified adult patients with ascending aortic dilation (≥4.0 cm) and serial gated computed tomography angiograms separated by ≥2 years, excluding confirmed heritable thoracic aortic disease. Ascending growth rate was defined as 90th percentile radial wall deformation by vascular deformation mapping. Maximal diameter measurements were derived from the baseline computed tomography angiogram, and aortic length and body size-adjusted indexes were calculated. Among 258 included patients (63.2% men; age of 63 years [interquartile range, 55-69 years]), mean±SD baseline diameter was 46.3±3.6 mm and median growth rate was 0.21 mm/year (interquartile range, 0.13-0.38 mm/year). No correlation was noted between growth rate and baseline diameter (r=0.02, P=0.74) or other aortic size metrics. On multivariate analysis, age was independently predictive of growth rate (β=-0.007, P=0.021), alongside weight (β=0.003, P=0.016) and the presence of moderate or severe aortic valve insufficiency (β=0.146, P=0.049). Maximal aortic diameter is not predictive of aortic growth rate, in this contemporary cohort of patients with sizes under current surgical thresholds (<55 mm).

8097 A Rare Case of a Renal Cell Carcinoma and Pheochromocytoma Collision Tumor

Abstract Disclosure: R. Daas: None. S. Logan: None. W. Sexton: None. V. Chumbalkar: None. M. McGettigan: None. C. Veloski: None. Background: Collision tumors are neoplasms comprised of two or more distinct tumors. A collision tumor consisting of a renal cell carcinoma and pheochromocytoma is extremely rare with less than five cases reported in the literature. Clinical Case: A 64-year-old male with a history of hypertension and type 2 diabetes presented with hematuria. The patient was on 4 anti-hypertensive medications at the time. He noted increased road rage, anxiety, tremors, and insomnia. A CT abdomen/pelvis revealed an exophytic 8.6 x 7.9 cm left upper pole renal mass and a 7.5 x 6.2 cm left adrenal mass. Contrast-enhanced MRI abdomen showed a left upper/interpolar renal mass with heterogenous peripheral enhancement, restricted diffusion, and areas of central necrosis along with a heterogenous, enhancing left adrenal mass with associated restricted diffusion and areas of cystic necrosis. Both masses had associated areas of hyperintense signal on T1 fat-suppressed MRI suggestive of hemorrhage. Lab work revealed ACTH 26.6 pg/mL (7.2-63.3), cortisol 13 ug/dL (3.7-19.4), aldosterone 23.1 ng/dL (4-31), renin 4 ng/mL/hr (0.5-4), dopamine 136 pmol/L (&amp;lt;240), epinephrine 121 pmol/L (&amp;lt;330), norepinephrine 23,666 pmol/L (1050-4800), plasma normetanephrines 12.3 nmol/L (0-0.89), plasma metanephrines &amp;lt;0.10 nmol/L (0-0.49), 24-hour urine normetanephrines 4,178 mcg (122-676) and 24-hour urine metanephrines 4,233mcg (224-832). The patient was treated with alpha blockade prior to left radical nephrectomy, left adrenalectomy and infrahilar paraaortic lymph node dissection. Despite aggressive preoperative alpha blockade with maximal doses of doxazosin, addition of metyrosine and other anti-hypertensives, he developed acute hypertension with adrenal mass manipulation during the procedure and then hypotension following removal. He was admitted to the ICU for management of hypotension with pressors and fluid resuscitation and did well. Post-operative labs showed plasma normetanephrines 0.98 nmol/L (0.00-0.89) and plasma metanephrines 0.11 nmol/L (0.00-0.49). Pathology revealed clear cell renal cell carcinoma (RCC) of the kidney. The adrenal gland showed 2 tumors; one consistent with pheochromocytoma and another intimately associated with the former consistent with metastatic RCC, morphology diagnostic of a collision tumor. Following surgical resection, the patient was referred for genetic testing, surveillance imaging and lab testing, and treated with pembrolizumab adjuvant therapy for stage IV RCC. Conclusion: Although collision tumors are rare, biochemical testing to rule out a pheochromocytoma must be performed for all indeterminate adrenal masses and presumed adrenal metastases of active malignancies. Presentation: 6/2/2024

8592 Parathyroid Carcinoma: A Rare Cause of Primary Hyperparathyroidism

Abstract Disclosure: S.E. Koshy: None. C.F. Mulcahy: None. P.S. Kothari: None. E.M. Jacobi: None. T.D. Cubb: None. Introduction: Parathyroid carcinoma (PC) is a rare malignancy that accounts for &amp;lt;1% of cases of primary hyperparathyroidism (PHPT). Patients often present with symptoms of hypercalcemia, serum calcium (Ca) &amp;gt;14 mg/dL, large tumor size, and a very high parathyroid hormone (PTH) level. We report a case of an asymptomatic patient with incidentally found hypercalcemia consistent with PHPT who was ultimately diagnosed with PC. Clinical Case: A 31yo male was found to have elevated serum Ca of 12.7 mg/dL (8.6-10.3 mg/dL) on labs obtained during routine physical exam. He had no known significant medical or family history and notably had no laboratory evaluation within the prior 10 years. He denied constipation, polyuria, confusion, depression, bone pain, and history of fractures or nephrolithiasis. Workup showed an inappropriately elevated PTH of 505 pg/mL (16-77 pg/mL). Neck ultrasound demonstrated a left inferior 3.9 cm complex thyroid nodule. Sestamibi scan confirmed increased uptake in the inferior left thyroid. Left neck exploration was performed. Intraoperatively, a 3.7 cm left parathyroid mass weighing 13.0 grams was encountered and excised in an en bloc fashion. The left superior parathyroid gland was evaluated and found to be normal. Intraoperative PTH level decreased from 529 pg/mL to 48 pg/mL 10 minutes after excision. Left hemithyroidectomy was not performed. Surgical pathology revealed PC with lymphovascular invasion, suspected capsular invasion, and negative margins. Immunohistochemical staining showed a Ki67 proliferation index up to 5% and complete loss of nuclear staining for parafibromin. Next generation sequencing demonstrated a somatic CDC73 p.L8fs mutation, tumor mutational burden 4.7m/MB, and stable microsatellite instability. Germline testing was negative for a CDC73 mutation. Postoperative staging did not demonstrate evidence of metastatic disease in the neck or chest. Serum Ca remained within normal limits. After multidisciplinary discussion, no further surgical intervention was recommended and plan was for ongoing biochemical and imaging surveillance. Conclusion: Though rare, PC should be considered as a cause of PHPT. The primary treatment is complete surgical resection. Unfortunately, there is a high rate of recurrence, &amp;gt;50%, with most occurring 2-5 years after initial surgery with a median overall survival of 14 years. Thus, long-term surveillance is of utmost importance. Treatment of recurrent disease is surgical resection when feasible as well as medical management of hypercalcemia. Further research is needed to better understand the role of targeted systemic therapy in addition to immunotherapy. PC is most commonly sporadic but can be hereditary, thus genetic evaluation is recommended. Given its rarity and complexity, PC is best managed in a multidisciplinary setting. Presentation: 6/1/2024

5179 Uncommon Benign Mimics Of Suspicious Adrenal Nodules

Abstract Disclosure: L. Zhu: None. L. Loh: None. V. Gan: None. P. Kek: None. Introduction: Adrenal incidentaloma is often detected in imaging studies. In addition to biochemical testing, imaging plays a key role in guiding the management of such lesions. We describe two uncommon cases of benign lesions masquerading as suspicious adrenal nodules. Case 1. A 54-year-old man with hypertension, diabetes, dyslipidaemia, ischaemic heart disease and atrial fibrillation (on warfarin) underwent CT scan to exclude malignancy when he presented with thigh DVT, and was found to have a right 3.2cm adrenal nodule. Adrenal hormone profile was unremarkable. CT contrast characterization showed attenuation of 30, 35, and 32 HU on pre-contrast, venous and 10-minute delayed phase respectively. Given the minimal enhancement in high density areas, possible haemorrhage was considered and he was put on imaging surveillance. CT scans over the following 5 years showed stability of the lesion, resolution of high-density areas, and pre-contrast attenuation of -35HU, suggestive of myelolipoma. Further follow-up over the next 2 years then revealed tumour enlargement to 8.5cm, progressive predominance of dense areas (58 HU), and development of compressive symptoms. In view of mass effect, growing heterogeneity and possibility of a collision tumour, right adrenalectomy was performed. Histopathology revealed myelolipoma with extensive haemorrhage and no evidence of malignancy. Case 2. A 65-year-old woman had hypertension, ischaemic heart disease, dialysis-dependent end-stage renal disease secondary to glomerulonephritis, and oncological history of left renal cell carcinoma (RCC) and low-grade papillary urothelial carcinoma, both surgically resected 10 years ago. A new 1.6cm right adrenal nodule was seen on her surveillance CT scan for RCC. It was not present in a CT scan 7 years ago. The nodule displayed suspicious features such as nodular avid rim enhancement, persistent enhancement on delayed phase of contrast washout and central cystic change. Biochemical screening revealed plasma free metanephrine of 0.33 nmol/L (NR: &amp;lt;0.33) and plasma free normetanephrine of 0.99 nmol/L (NR: &amp;lt;0.71). Other adrenal hormone profiles were unremarkable. Cystic phaeochromocytoma was suspected and she underwent right adrenalectomy and nephrectomy following alpha blockade. Histopathology revealed a well-circumscribed nodule in the supra-renal adipose tissue, with vascular proliferation and features of anastomosing haemangioma. The right kidney was reported to have acquired cystic disease associated RCC. She was well post-operatively and remained on follow-up with the urologist for her RCC. Discussion: Haemorrhagic adrenal myelolipoma and supra-renal anatomosing haemangioma are benign lesions that may have CT characteristics similar to those of sinister lesions. Pre-operative diagnosis can be challenging. Surgical excision may be required to confirm diagnosis and exclude malignancy. Presentation: 6/3/2024

8592 Parathyroid Carcinoma: A Rare Cause of Primary Hyperparathyroidism

Abstract Disclosure: S.E. Koshy: None. C.F. Mulcahy: None. P.S. Kothari: None. E.M. Jacobi: None. T.D. Cubb: None. Introduction: Parathyroid carcinoma (PC) is a rare malignancy that accounts for &amp;lt;1% of cases of primary hyperparathyroidism (PHPT). Patients often present with symptoms of hypercalcemia, serum calcium (Ca) &amp;gt;14 mg/dL, large tumor size, and a very high parathyroid hormone (PTH) level. We report a case of an asymptomatic patient with incidentally found hypercalcemia consistent with PHPT who was ultimately diagnosed with PC. Clinical Case: A 31yo male was found to have elevated serum Ca of 12.7 mg/dL (8.6-10.3 mg/dL) on labs obtained during routine physical exam. He had no known significant medical or family history and notably had no laboratory evaluation within the prior 10 years. He denied constipation, polyuria, confusion, depression, bone pain, and history of fractures or nephrolithiasis. Workup showed an inappropriately elevated PTH of 505 pg/mL (16-77 pg/mL). Neck ultrasound demonstrated a left inferior 3.9 cm complex thyroid nodule. Sestamibi scan confirmed increased uptake in the inferior left thyroid. Left neck exploration was performed. Intraoperatively, a 3.7 cm left parathyroid mass weighing 13.0 grams was encountered and excised in an en bloc fashion. The left superior parathyroid gland was evaluated and found to be normal. Intraoperative PTH level decreased from 529 pg/mL to 48 pg/mL 10 minutes after excision. Left hemithyroidectomy was not performed. Surgical pathology revealed PC with lymphovascular invasion, suspected capsular invasion, and negative margins. Immunohistochemical staining showed a Ki67 proliferation index up to 5% and complete loss of nuclear staining for parafibromin. Next generation sequencing demonstrated a somatic CDC73 p.L8fs mutation, tumor mutational burden 4.7m/MB, and stable microsatellite instability. Germline testing was negative for a CDC73 mutation. Postoperative staging did not demonstrate evidence of metastatic disease in the neck or chest. Serum Ca remained within normal limits. After multidisciplinary discussion, no further surgical intervention was recommended and plan was for ongoing biochemical and imaging surveillance. Conclusion: Though rare, PC should be considered as a cause of PHPT. The primary treatment is complete surgical resection. Unfortunately, there is a high rate of recurrence, &amp;gt;50%, with most occurring 2-5 years after initial surgery with a median overall survival of 14 years. Thus, long-term surveillance is of utmost importance. Treatment of recurrent disease is surgical resection when feasible as well as medical management of hypercalcemia. Further research is needed to better understand the role of targeted systemic therapy in addition to immunotherapy. PC is most commonly sporadic but can be hereditary, thus genetic evaluation is recommended. Given its rarity and complexity, PC is best managed in a multidisciplinary setting. Presentation: 6/1/2024

8194 Extramedullary Hematopoiesis Involving Bilateral Adrenal Glands In A Patient With Sickle Cell Anemia

Abstract Disclosure: V.T. Pham: None. L.N. Sendos: None. Title: Extramedullary hematopoiesis involving bilateral adrenal glands in a patient with sickle cell anemia Background: Extramedullary hematopoiesis refers to blood cell production occurring outside the bone marrow. It is a reactive process caused by inadequate production or excessive destruction of blood cells typically seen in patients with hereditary anemias or infiltrative bone marrow disorders. Extramedullary hematopoiesis usually occurs in the spleen, liver and lymph nodes, but it can also very rarely arise from the adrenal glands. Case Presentation:We present a case of a 42-year-old male with a history of sickle cell anemia who presented with chest pain and shortness of breath and had a chest CT angiography which incidentally showed a 5.6 x 3.8 cm left adrenal mass and a 2.9 x 2.1 cm right adrenal mass. Further evaluation with an MRI abdomen with and without contrast revealed a 5.5 cm lobulated left adrenal mass with patchy areas of microscopic fat and faint delayed heterogeneous enhancement as well as a 2.2 cm right adrenal nodule. The nodules were described as markedly T2 hypointense with heterogeneous T1 hyperintense/isointense signal on MRI with a broad differential diagnosis including extramedullary hematopoiesis in bilateral adrenal glands, lipid poor adenoma or neoplasm. Regarding his sickle cell disease history, the patient was diagnosed as an infant and had very rare episodes of sickle cell pain crisis as a child. However, once he entered adulthood, he began to have multiple episodes of sickle cell pain crisis requiring hospitalizations and transfusions. On further review of patient’s prior imaging scans during these previous hospitalizations, he was first noted to have bilateral sub centimeter adrenal nodules on a CT Abdomen without contrast done almost a decade prior to his current presentation. We ordered biochemical evaluation which did not show any evidence of adrenal hormonal hypersecretion. His case was discussed at our multidisciplinary conference with the radiology and surgery team and it was concluded that the imaging characteristics were most consistent with extramedullary hematopoiesis in the setting of bilateral adrenal gland involvement and patient’s history of sickle cell anemia. Therefore, no immediate surgical resection was recommended. Given the size of the left adrenal mass being greater than 4 cm in size, we advised follow-up imaging for surveillance. Discussion:There has been a rise in detection of adrenal incidentalomas due to the increased use of advanced diagnostic imaging in healthcare settings. When patients with hematologic diseases are found to have adrenal incidentalomas, it is important to consider extramedullary hematopoiesis in the differential diagnosis to avoid unnecessary invasive procedures and surgeries. Presentation: 6/2/2024