Surveillance CT Scans Research Articles

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: <0.33) and plasma free normetanephrine of 0.99 nmol/L (NR: <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

O156: Post-operative surveillance following curative resection of colorectal cancer in an elderly population

Abstract Introduction There are over 42,000 new cases of colorectal cancer in the UK each year with the highest incidence rates in those aged 85-89. Post-colorectal cancer surveillance aims to reduce cancer incidence and mortality, but its necessity and effectiveness remain debated especially in an elderly population. This study explores the relevance of computer tomography (CT) and colonoscopy surveillance in patients aged 75 and over who have undergone curative resection for colorectal cancer. Methods A retrospective analysis of prospectively collected data was conducted on patients aged 75 and over who had undergone surgical resection of colorectal cancer between November 2014 and August 2021. Data on demographics, treatment, survival, and surveillance were gathered from electronic patient records. The primary outcome was adherence to follow-up colonoscopy and CT-scan surveillance following surgery. Results A total of 417 patients underwent colorectal cancer surgery, with 334 included for analysis. Twelve-month CT surveillance showed normal results in 91.8% of cases, while 24-month CT surveillance demonstrated normal findings in 88.7%. Only 52.4% had colonoscopy follow-up, with 53.7% showing normal results, 42.3% demonstrated benign polyps, and 1.1% had histologically proven cancer. Reasons for not undergoing colonoscopy included patient preference (19.1%) and frailty (28.7%). Conclusion This study reinforces the notion that colonoscopy surveillance in patients over 75 may have limited benefits. In an aging population, benefits of surveillance in terms of early detection of recurrence must be balanced against the risks of harm from the procedure, availability of further management, cost-effectiveness, and patients’ preference.

Usefulness of longitudinal nodule-matching algorithm in computer-aided diagnosis of new pulmonary metastases on cancer surveillance CT scans.

Detecting new pulmonary metastases by comparing serial computed tomography (CT) scans is crucial, but a repetitive and time-consuming task that burdens the radiologists' workload. This study aimed to evaluate the usefulness of a nodule-matching algorithm with deep learning-based computer-aided detection (DL-CAD) in diagnosing new pulmonary metastases on cancer surveillance CT scans. Among patients who underwent pulmonary metastasectomy between 2014 and 2018, 65 new pulmonary metastases missed by interpreting radiologists on cancer surveillance CT (Time 2) were identified after a retrospective comparison with the previous CT (Time 1). First, DL-CAD detected nodules in Time 1 and Time 2 CT images. All nodules detected at Time 2 were initially considered metastasis candidates. Second, the nodule-matching algorithm was used to assess the correlation between the nodules from the two CT scans and to classify the nodules at Time 2 as "new" or "pre-existing". Pre-existing nodules were excluded from metastasis candidates. We evaluated the performance of DL-CAD with the nodule-matching algorithm, based on its sensitivity, false-metastasis candidates per scan, and positive predictive value (PPV). A total of 475 lesions were detected by DL-CAD at Time 2. Following a radiologist review, the lesions were categorized as metastases (n=54), benign nodules (n=392), and non-nodules (n=29). Upon comparison of nodules at Time 1 and 2 using the nodule-matching algorithm, all metastases were classified as new nodules without any matching errors. Out of 421 benign lesions, 202 (48.0%) were identified as pre-existing and subsequently excluded from the pool of metastasis candidates through the nodule-matching algorithm. As a result, false-metastasis candidates per CT scan decreased by 47.9% (from 7.1 to 3.7, P<0.001) and the PPV increased from 11.4% to 19.8% (P<0.001), while maintaining sensitivity. The nodule-matching algorithm improves the diagnostic performance of DL-CAD for new pulmonary metastases, by lowering the number of false-metastasis candidates without compromising sensitivity.

P17 Hepatobiliary parasitic infestation: a case report

Abstract Background Hepatic parasitic lesions can present with multiple cystic lesions that may simulate inflammatory pseudo-tumour or malignancy in appropriate clinical settings. Here we present a known case of renal cell carcinoma with liver lesions that showed parasitic infestation on histology. Patient case A 70-year-old male with a history of right partial nephrectomy for clear cell renal cell carcinoma having an uneventful postoperative follow-up for 2 years underwent a surveillance CT scan. Multiple hepatic cystic lesions were identified, which on subsequent MRI and PET scan were suspicious for metastasis. Partial hepatectomy was performed for histological evaluation. Results Multiple discrete cystic hepatic lesions were noted on macroscopy. Histological examination revealed multiple necrotic hyalinized nodules with granulomatous inflammation within the liver and dense neutrophil infiltration with microabscess formation. Within the central necrotic area, there were non-viable parasite eggs and parts of worm, in keeping with parasitic infestation. On further expert opinion, this was diagnosed as Enterobius infestation of liver. Conclusions Hepatobiliary parasitic infestations may be encountered as clinically and biochemically asymptomatic lesions, especially in immunocompromised patients. Strong clinical history of travel and parasite serology screen is always helpful to clinch the diagnosis but may not be always available during histological examination. This case highlights the importance of thorough histological and microbiological examination as all nodular lesions in liver are not malignant and could be infective.

Post-operative Surveillance Following Curative Resection of Colorectal Cancer in the Elderly Population in the United Kingdom: An Observational Study.

Background Colorectal cancer most commonly affects the elderly population. Post-colorectal cancer surveillance aims to reduce cancer incidence and mortality, but its necessity and effectiveness are debated, especially in the elderly population. This study explores the relevance of computer tomography (CT) and colonoscopy surveillance in patients aged 75 and over who have undergone curative resection for colorectal cancer. Methods A retrospective analysis of prospectively collected data was conducted on patients aged 75 and over who had undergone surgical resection of colorectal cancer between November 2014 and August 2021. Data on demographics, treatment, survival, and surveillance were gathered from electronic patient records. The primary outcome was adherence to follow-up colonoscopy and CT-scan surveillance following surgery. Results A total of 417 patients underwent colorectal cancer surgery, with 334 included for analysis. The cohort had an average age of 81 years, with the majority receiving laparoscopic surgery and primary anastomosis. Twelve-month CT surveillance showed normal results in 281 patients (91.8%), while 24-month CT surveillance demonstrated normal findings in 244 patients (88.7%). Only 175 patients (52.4%) had colonoscopy follow-up, with 94 (53.7%) showing normal results, 74 (42.3%) demonstrating benign polyps, and two patients (1.1%) having histologically proven cancer. Reasons for not undergoing colonoscopy included declining invitations (30 patients, 19.1%) and being too frail (45 patients, 28.7%). Conclusion This study reinforces the notion that colonoscopy surveillance for patients over the age of 75 may have limited benefits. In an ageing population, the benefits of surveillance in terms of early detection of recurrence must be balanced against the risks of harm from the procedure, the availability of further management, cost-effectiveness, and patient preferences. An individualised approach should be adopted, potentially with colonoscopy surveillance only recommended in patients of higher risk (extramural venous invasion (EMVI)) and a low frailty score with a life expectancy over 10 years.

1065 Radical Nephrectomy and Inferior Vena Cava (IVC) Thrombectomy: Management of Level IV Thrombus

Abstract Introduction IVC invasion with tumour thrombus occurs in 10-25% of renal cell carcinoma (RCC) patients (1). IVC thrombi are classified according to anatomical levels. Cardiopulmonary bypass is indicated for level IV thrombi which extend above the diaphragm, including atrial thrombi or when the reduction in cardiac output with IVC cross-clamping cannot be tolerated. This technique maintains haemodynamic stability and allows better vision during thrombectomy. Case report A 46-year-old male presented with a three-week history of vague abdominal pain and night sweats. Subsequent CT thorax, abdomen &amp; pelvis, and MR venogram found a 10cm right renal tumour extending into the right renal vein, inferior vena cava and tumour thrombus extending 50% into the right atrium. Management Following MDT discussion, this gentleman underwent right radical nephrectomy, IVC thrombectomy, sternotomy and retrieval of tumour thrombus from his right atrium. This was performed under approximately one hour of deep hypothermic circulatory arrest. The patient made an excellent recovery with 10 days spent in hospital post-operatively. His histology subsequently showed a clear cell renal carcinoma, ISUP grade 3, with positive vein margin. Its final staging was pT3cN0R1. Follow up was with three monthly surveillance CT scans. Discussion The median survival of untreated RCC patients with venous thrombi is just 5 months, thus, this is lifesaving and very urgent surgery (2). Procedures for Level 4 IVC thrombi should take place in high volume centres with access to both cardiothoracics for cardiopulmonary bypass or veno-venous bypass and surgeons with expertise in vascular reconstruction and liver mobilization.

External validation of biomechanical computed tomography for fracture risk classification in metastatic hormone sensitive prostate cancer.

e24077 Background: For men with metastatic hormone-sensitive prostate cancer (mHSPC) on androgen deprivation therapy (ADT), guidelines recommend dual-energy X-ray absorptiometry (DXA) screening to identify fracture risk and benefit from antiresorptive therapy. However, only 8% of men with mHSPC receive routine DXA screening. Biomechanical computed tomography (BCT) is a radiomic technique that measures bone mineral density (BMD) and bone strength from routine staging and surveillance CT scans but has not been validated in mHSPC. Methods: This retrospective cohort study included 99 patients with incident mHSPC beginning ADT (2013-2020) at one academic (n = 70) and one tertiary VA medical center (n = 29) with CT abdomen/pelvis or PET/CT imaging at baseline (within 1 year prior to ADT initiation) and follow-up (1-2 years after ADT initiation). BCT-assessed BMD T-score and femoral strength were calculated from baseline and follow-up CT scans. We evaluated the association between BCT measures and subsequent pathologic and non-pathologic fractures within 3 years following mHSPC diagnosis. Results: Among 99 patients, mean age was 68 years, 48 (48.5%) were White, and 45 (45.4%) were Black. During median follow-up of 19 months, 23 (24%) developed a pathologic and 15 (15%) a non-pathologic fracture. BCT and DXA-assessed femoral-neck BMD T-score were strongly correlated (R2= 0.94, N = 23). Higher BCT-assessed baseline BMD (Odds Ratio [OR] 0.5, p = 0.03) and bone strength (OR 0.57, p = 0.02) were each associated with decreased pathologic fracture (Table). Neither BMD nor bone strength were significantly associated with non-pathologic fracture. BCT identified 10 (10%) men eligible for antiresorptive therapy by established BMD, strength, or FRAX criteria at ADT initiation, 4 (40%) of whom never received it by the end of follow-up. Between baseline and follow-up, both BMD (-0.27) and bone strength (-0.34) decreased among patients who did not receive antiresorptive therapy (n = 76), with no difference in longitudinal change between ADT alone vs with androgen receptor signaling inhibitors. Conclusions: In this diverse, multicenter cohort of men with mHSPC beginning ADT, BCT BMD assessed from routine CT scans strongly correlated with DXA-assessed BMD. BCT measurements predicted subsequent pathologic fracture and identified additional men who would benefit from antiresorptive therapy. BCT may provide a practical method to assess the role for anti-resorptive therapy in patients with mHSPC. [Table: see text]

Evaluation of the GELTAMO guidelines for surveillance in follicular lymphomas after first‐line immunochemotherapy: a real‐world prospective study

Introduction: CT scans have been traditionally recommended in the surveillance of patients (pts) with follicular lymphoma (FL) by international societies. In asymptomatic FL pts responding to first line (1L) immunochemotherapy, the Spanish GELTAMO FL guidelines recommends CT scan every 6 months for 2 years (during rituximab maintenance). The real value of surveillance with CT scans remains an open question, even more after the incorporation of PET in the response evaluation of FL. Our aim was to evaluate the detection rate of relapses by CT surveillance according to GELTAMO guidelines in FL pts with complete metabolic response (CMR) or partial metabolic response (PMR). Methods: observational prospective study in a single center between 2008 and 2020. Newly diagnosed FL who had CMR or PMR to 1L therapy were identified. Evaluation for both relapse and method of relapse detection, having special interest in the CT surveillance according to GELTAMO guidelines. Results: From 108 FL treated pts, 81 were included in the final analysis. Median age and female proportion were 59 years (range 24–83) and 49.4%. Treatment: R-CHOP/R-CHOP-like 63%, R-CVP 15% and rituximab 22%. Response: CMR 82%, PMR 18%. Median follow-up was 79.7 months (IQR 57.8–117.3). A total of 29 pts relapsed or progressed (35.8%) during the whole study period: 24 from CMR and 5 from PMR. Of these pts, 9 relapsed in the first 2-y (31.0% of all relapses and 11.1% of all patients) and were more common in pts in PMR versus CMR (60% vs. 25%, p = 0.1238). Relapse detection method in the first 2-y was: 5 (55.5%) by CT scan, 2 by physical examination and 2 by other methods. Beyond 2-y, 12 (60%) were detected by physical examination, 5 (25%) by CT scan, 2 (10%) by blood tests and 1 (5%) by ultrasound echography. Protocol adherence was 75.3%. A total of 262 CTs were performed in first 2-y with only 5 positive CT scans in this time-lapse (diagnostic yield 2%). Globally, 17.2% of all relapses were diagnosed by GELTAMO recommended surveillance CT scans. Time from first relapse to second line treatment was 4.02 months in those with relapse detected by CT in schedule versus 2.03 months in those detected by other methods (p = 0.81) (Figure 1A). In relapsed pts, OS at 3-y from relapse was 30.0 months in those with relapse detected by CT in schedule versus 66.2 months in the other patients (p = 0.077) (Figure 1B), probably because of the enrichment of POD24 cases in the first group. However, OS at 3-y from relapse in those patients in which relapse was detected by CT at any time (in or out schedule) was 43.8 months versus 66.9 months in those detecting relapse by other methods (p = 0.19). Keywords: Imaging and Early Detection, Indolent non-Hodgkin lymphoma, PET-CT No conflicts of interests pertinent to the abstract.

Abstract 15814: Postoperative Surveillance Imaging Following Elective Aortic Hemiarch Replacement

Introduction: The optimal protocol for imaging following aortic hemiarch replacement remains a topic of debate with varied intervals at each institution. For the last 3 years, our institution has surveilled patients at 3 months, yearly for 3 years, and at 5 years. Hypothesis: We hypothesize surveillance CT scans performed at 3 months will identify any pathologies related to the ascending aortic repair that will require re-intervention; additional imaging may be superfluous. Methods: Using our single institution-maintained database, 348 patients who underwent an elective aortic hemiarch repair between February of 2010 and December of 2021 were identified. One patient with a restricted chart was excluded. The timing for and stability of surveillance imaging was reviewed, paying special attention to pathology associated with the repair. Results: Of the 347 patients, 274 completed surveillance imaging. 231 patients had their initial imaging around 3 months following the operation, 126 patients completed imaging around one year, and 72 patients were imaged 2-10 years post-operatively with some patients undergoing multiple scans during this period. Ten patients required re-intervention; of these 10, two patients demonstrated pathology, on CT scan, associated with the actual ascending aortic repair. These two patients developed a pseudoaneurysm (PSA), one at the distal aspect of the repair and one at the left ventricular outflow tract. Another two patients had degeneration of known distal aortic aneurysms. The two PSAs were intervened upon within the first 3 months and the degenerating aneurysms were intervened upon at 1 and 2.5 years post-operatively. Conclusions: These data support surveillance imaging completed at 3 months following hemiarch replacement is sufficient to identify pathology related to the repair. While other indications may dictate ongoing surveillance, for most patients, the need for further imaging is potentially zero.

PSAT016 Deoxycorticosterone-Producing Adrenocortical Carcinoma: A Rare Cause of Resistant Hypertension

Abstract Background Rare causes of secondary hypertension should be considered after negative initial evaluation for more common conditions. 11-Deoxycorticosterone-secreting tumors are one such rare cause. Clinical Case A 38-year-old male with two-year history of resistant hypertension on four antihypertensive medications (amlodipine, hydrochlorothiazide, lisinopril, spironolactone) presented to the emergency room with one-day history of headaches and hypertension. Initial vitals were blood pressure of 179/117, heart rate 68, respiratory rate 18, and SpO2 of 100% on room air. Labs were notable for hypokalemia of 2.2, normal creatinine of 1.03, and troponin elevation of 0.08. EKG showed no ischemic changes. During the hospital admission, spironolactone dose was increased, amiloride was added, hydrochlorothiazide was discontinued, and potassium was supplemented. The patient's blood pressure stabilized, and troponin normalized. Evaluation for secondary causes was also initiated, including plasma renin, aldosterone, and metanephrines, with results pending on discharge. Outpatient CT abdomen and pelvis was also ordered. The patient was discharged on the third day of admission on an increased dose of spironolactone 100mg daily, amiloride 5mg daily, amlodipine 10mg daily, lisinopril 40mg daily, and potassium 20meq twice daily. Laboratory studies and outpatient endocrinology evaluation revealed suppressed plasma renin activity 0.1 ng/mL/hr, low aldosterone &amp;lt;3.0 ng/dL, elevated 11-deoxycorticosterone (DOC) 869 ng/dL (reference range ≤19 ng/dL), and elevated 11-deoxycortisol 719 ng/dL (reference range ≤49 ng/dL). Plasma and urine metanephrines, 24-hour urinary free cortisol, and plasma DHEAS were normal. CT revealed a large 9.7×10.0×10.7cm heterogeneously enhancing right adrenal mass and several subcentimeter bilateral pulmonary nodules. FDG PET-CT showed mild heterogeneous uptake of the adrenal mass with SUVmax of 5.1 and hepatic SUVmean of 2.5, without convincing metabolic evidence of metastasis. Mild uptake was noted in the mediastinal, hilar and left axillary lymph nodes, which were not suspiciously hypermetabolic and favored to be reactive, perhaps related to recent COVID-19 vaccination administered to the left upper extremity. The subcentimeter pulmonary nodules did not have increased avidity. The patient underwent open right adrenalectomy without complications. Pathology revealed 11.5cm low-grade adrenocortical carcinoma with clear margins and angioinvasion, Ki67 proliferation index of 1-2%, and without necrosis, lymphovascular invasion, or extra-adrenal extension. 11-deoxycortisol normalized and DOC was undetectable at one and three months postoperatively. Blood pressure improved significantly, and all antihypertensives were discontinued except amlodipine 10mg daily. On surveillance CT scan six months after surgery, there was no evidence of residual disease in the adrenalectomy bed and pulmonary nodules appeared stable. Conclusions Adrenocortical carcinomas rarely produce aldosterone and even less commonly produce DOC as the major steroid product. DOC should be evaluated in the setting of hypertension with hypokalemia, suppressed renin and aldosterone. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

S2372 Severe Dysphasia With Eosinophilic Esophagitis Pattern of Injury and Autoimmune Gastritis Related to Pembrolizumab Therapy

Introduction: Immune checkpoint inhibitor (ICI) therapies are effective treatments of many cancer types, including non-small cell lung carcinoma of the lung (NSCLC). While efficacious, ICI therapy can be associated with immune-related adverse effects (irAEs). We present a 67-year-old man with NSCLC who developed severe dysphasia with an eosinophilic esophagitis (EoE) pattern of injury on histopathology and concomitant autoimmune gastritis while on pembrolizumab maintenance therapy. Case Description/Methods: A 67-year-old man with NSCLC on 3 years of maintenance pembrolizumab with stable disease presented to GI clinic for evaluation of progressively worsening solid and liquid food dysphagia with regurgitation. Surveillance CT scans prior to advent of symptoms showed stable mediastinal lymphadenopathy with stable external compression of the mid-esophagus. A barium swallow study showed narrowing of the mid-esophagus. An EGD was performed and showed mid-esophageal lumen narrowing (Figure). Biopsies were obtained from the distal esophagus and showed up to 42 intraepithelial eosinophils (Eo) per high power field, consistent with an EoE pattern of injury. A subsequent EGD with stomach mapping prior to initiation of therapy showed concurrent autoimmune gastritis with no increase of Eo infiltrates. PPI therapy twice a day was initiated but the symptoms did not improve after 2 months. Topical glucocorticoid therapy with budesonide was then started. Despite dual therapy, his dysphagia progressed. Pembrolizumab was discontinued and docetaxel with ramucirumab was started, which resulted in a complete resolution of his dysphagia symptoms. Patient was maintained on PPI therapy with a plan to repeat EGD. Discussion: While GI irAEs are increasingly recognized, ICI-EoE is a rare entity. In the literature, only one other case of ICI-EoE has been reported. This patient’s dysphagia in the context of >15 intraepithelial Eo per high power field without other identifiable etiologies of increased esophageal Eo, and the resolution of symptoms with the discontinuation of pembrolizumab is consistent with ICI-EoE. In addition, the patient had concomitant autoimmune gastritis, which is also a rare but increasingly recognized irAE. Our case demonstrated both entities presenting in one patient. Treatment of irAEs often involves discontinuation of the ICI. Refractory cases may require systemic immunosuppression with corticosteroids or biologic therapy.Figure 1.: 1A – Mid-esophageal narrowing on barium swallow study Figure 1B – Intraepithelial eosinophilia consistent with EoE.

SP2.2.1 Surgical Resection of metastases to the adrenal gland

Abstract Aims The adrenal gland is a common metastatic site for lung, breast, skin, renal, thyroid, and colorectal cancers. Our aim was to review resection of adrenal metastases and their primary pathology and the impact of adrenalectomy on the survival and disease free survival rate. Methods Retrospective review of adrenalectomy for adrenal metastases in a single regional centre between June 2010–2020. Results 34 adrenalectomies in 33 patients were performed. Median age of patients was 70 (39–82). All adrenal lesions were diagnosed on staging or surveillance CT scan. Isolated adrenal metastases were seen in 26 patients. The most common primary malignancy was renal cell carcinoma (RCC) (n=20), followed by non small cell lung cancer (NSCLC) (n=6), colorectal adenocarcinoma (n=2) and infiltrating ductal breast carcinoma (n=2). Other primaries include malignant melanoma, oesophageal adenocarcinoma, prostate adenocarcinoma and hepatocellular carcinoma (each n=1). Adrenalectomy was carried out for diagnosis in 5 cases, 4 where no resection of the primary lesion was performed. Median time from resection of primary lesion was 4 years (1–16). 5 patients had synchronous adrenal metastases, 1 with synchronous resection of primary. At the time of writing, there was a 38% mortality. 84% of deaths were due to disease progression. Median survival from adrenalectomy was 23 months (4–52 months). Of the surviving patients 76% are disease free and under oncological or clinical surveillance. 24% underwent further systemic or localised oncological therapy. Conclusions Survival rate following adrenalectomy for metastatic deposits is 62%. Better outcomes are observed in patients with RCC metastases.

The utility of surveillance CT scans in a cohort of survivors of colorectal cancer.

Colorectal cancer (CRC) is the third most common cancer worldwide. After curative intent treatment, international guidelines recommend surveillance protocols which include annual CT chest, abdomen and pelvis (CAP) and serum carcinoembryonic antigen (CEA) monitoring which aim to improve overall survival by early detection of recurrence. Despite the widespread recommendations, robust evidence of an overall survival benefit is lacking. Our study aimed to quantify the utility of annual CT CAP as a surveillance modality in comparison to the rate of potentially harmful false-positive and incidental findings. High-risk stage II and stage III CRC patients were retrospectively identified from the Sydney Cancer Survivorship Centre database. Findings on surveillance CT were classified into confirmed recurrence or the potentially harmful findings of (a) false-positive or (b) clinically significant incidental finding. A total of 376 surveillance CT CAPs were performed in 174 survivors between 12 September 2013 and 30 June 2020. The recurrence rate during the study period was 23/174 (13.2%) with the majority of recurrences detected by abnormal CEA (14/23, 60.9%) versus surveillance CT (4/23, 17.4%), with the remainder identified on non-surveillance CT (5/23, 21.7%). Curative intent surgery was performed in 12/23 people with CRC recurrence. Surveillance CT was shown to result in high levels of false-positive (31/174, 17.8% of patients) or clinically significant incidental findings (30/174, 17.2% of patients). The risk of identifying these potentially harmful findings was ongoing with each year of surveillance CT. Surveillance CT was associated with low detection rates and high rates of potentially harmful findings bringing this surveillance modality under further scrutiny. An increased emphasis should be placed on educating survivors on the benefits of surveillance CT weighed against the risk of potentially harmful findings.

Abstract 12550: Overexposed? Evaluating the Need for Serial Surveillance Imaging Following Elective Aortic Hemiarch Replacement

Introduction: The optimal timing for imaging following ascending aortic replacement is unknown. Protocols currently differ based on institution. For the last 3 years, our institution has surveilled patients at 3 months, yearly for 3 years, and at 5 years following the operation. Hypothesis: We hypothesize surveillance CT scans performed at 3 months will identify any pathologies related to the ascending aortic repair that will require re-intervention; additional imaging may be superfluous. Methods: Using our single institution-maintained database, 311 patients who underwent an elective aortic hemiarch repair between February of 2010 and March of 2021 were identified. The timing for and stability of surveillance imaging was reviewed, paying special attention to pathology associated with the repair. Results: Of the 311 patients who underwent elective aortic hemiarch repair, 217 completed surveillance imaging. 187 patients had their initial imaging around 3 months following the operation, 85 patients completed imaging around one year, and 54 patients were imaged 2-8 years post-operatively with some patients undergoing multiple scans during this period. Nine patients required re-intervention; of these 9, four patients demonstrated pathology, on CT scan, associated with the actual ascending arch repair. Two patients developed a pseudoaneurysm (PSA), one at the distal aspect of the repair and one at the left ventricular outflow tract. The other two patients had degeneration of known distal aortic aneurysms. The two PSAs were intervened upon within the first 3 months and the degenerating aneurysms were intervened upon at 1 and 2.5 years post-operatively. Conclusions: These data support surveillance imaging completed at 3 months following ascending aortic replacement is sufficient to identify pathology related to the repair. While other indications may dictate ongoing surveillance, for most patients, the need for further imaging is potentially zero.

Phase 2 Study of Nivolumab in Epstein-Barr Virus (EBV)-Positive Lymphoproliferative Disorders and EBV-Positive Non-Hodgkin Lymphomas

Introduction: Immune tolerance and evasion plays a significant role in the pathogenesis of EBV+ lymphoproliferative disorders (LPD) and non-Hodgkin lymphomas (NHL). Programmed cell death protein-1 (PD-1) is a signaling molecule on the surface of T-cells that suppresses the cytotoxic effects of T-cells on tumor cells. PD-L1 expression is a marker of poor prognosis in aggressive lymphomas and most EBV+ LPDs demonstrate high levels of PD-L1 expression. Chronic viral infections, such as EBV, also result in T-cell exhaustion that can be reversed by PD-1 blockade. Nivolumab is a fully human IgG4 monoclonal anti-PD-1 antibody which has demonstrated activity and favorable safety in lymphoid malignancies. We hypothesized that PD-1 blockade may reverse the inactivation of tumor-specific effector T-cells and result in anti-tumor responses in EBV+ LPD and NHL.Methods: Relapsed/refractory (R/R) EBV+ LPD and B-cell NHL pts age ≥ 12y with adequate organ function are eligible. Untreated pts are eligible if EBV+ LPD. Exclusions include prior use of PD-1/PD-L1/PD-L2/CD137/CTLA-4 antibodies, prior solid organ transplant and HIV. Pts with immunodeficiency or autoimmune illness are eligible if not requiring steroids or immunosuppression. CNS involvement is permitted if no seizure activity within 4 weeks of study. Nivolumab 480mg IV is given every four weeks for up to 2y. Pts who achieve CR discontinue nivolumab after 1y of treatment. Baseline evaluation includes CT, PET, MRI brain, flow cytometry of peripheral blood and CSF, BM biopsy along with optional tumor biopsy. CT scans are performed after cycles 3, 6, 13 and 19 and end of treatment (EoT). PET is performed after cycles 1, 3 and EoT. Surveillance CT scans are performed q3m for 1y, q6m for yrs 2-5, and annually thereafter.Results: 9 pts, 7 (78%) R/R and 2 (22%) untreated, enrolled between April 2018 and May 2021; 5 (56%) with EBV+ LPD [4 G1-2 lymphomatoid granulomatosis (LYG) and 1 chronic active EBV disease (CAEBV)] and 4 (44%) with EBV+ NHL (all DLBCL, NOS). Median age was 48y (range 30-63) and all pts (100%) had stage III/IV disease. Four pts (44%) had elevated LDH (all DLBCL). Median baseline CD4 and CD8 count (cells/mcL) was 378 (range 99-984) and 86 (range 22-1237), respectively, for LPD and 190 (range 133-255) and 90 (range 9-630), respectively, for NHL. Median EBV VL at baseline (Log10 IU/mL) was 2.55 (range 0-6.78) and 2.53 (range 0-5.33) for LPD and NHL, respectively. Eight (89%) pts had extranodal disease with pulmonary involvement most common in 6 (67%). Median prior therapies were 1 (range 0-1) and 2 (range 1-4) for LPD and NHL pts, respectively. Three (43%) R/R pts were refractory (i.e., <PR) to last therapy.Of 9 pts enrolled, 7 were evaluable for response (1 NHL pt died prior to restaging and 1 NHL pt has not yet been restaged). In 6 measurable pts, tumor reduction was observed in 67% (Fig 1A). ORR and CR rate was 57% (4/7) and 43% (3/7), respectively; 60% (3/5) and 40% (2/5) in LPD and 50% (1/2) and 50% (1/2) in NHL. Median TTR was 3.0m with 3 (75%) of 4 responses ongoing from 6.9m to 35.2m after first response (Fig 1B).Most common adverse events (AEs) (% pts) included maculopapular rash (38%), ALT elevation (25%), AST elevation (25%), CPK elevation (25%) and fatigue (25%). One pt discontinued therapy due to G2 immune-mediated myositis that required prolonged steroid therapy. >G3 AEs included AST elevation in 1 (13%) pt with no G4/G5 or serious adverse events.With a median potential follow up of 12.6m, 12-month PFS and OS was 50.8% (95% CI: 15.7-78.1) and 75.0% (95% CI: 31.5-93.1). In LPD pts, 12-month PFS and OS was 80% (95% CI: 20.4-96.9) and 100%. Three (75%) NHL pts progressed and 2 (50%) died of disease progression. One NHL pt stopped therapy due to apparent disease progression after 2 cycles but later developed CR without further therapy and remains in remission 35.2m after stopping therapy.Conclusion: Nivolumab appears safe in pts with EBV+ LPD and NHL without unexpected toxicities. Preliminary clinical activity, including CRs, is noted in pts with EBV+ LPD and NHL. Additional pts are needed for a better assessment of true activity in these rare entities and correlates of response including PD-1/PD-L1 expression and/or 9p24.1 alterations are ongoing and will be presented at the meeting. [Display omitted] DisclosuresNo relevant conflicts of interest to declare. OffLabel Disclosure:Nivolumab for EBV+ LPD and EBV+ NHL.

CHYLOTHORAX AS A RARE COMPLICATION OF ENDOSCOPIC ULTRASOUND WITH FINE NEEDLE ASPIRATION

TOPIC: Procedures TYPE: Medical Student/Resident Case Reports INTRODUCTION: Trans-esophageal endoscopic ultrasound with fine-needle aspiration (EUS-FNA) is a relatively safe and minimally invasive procedure used to diagnose and stage mediastinal masses. Chylothorax is an extremely rare complication of EUS-FNA which can be fatal without timely intervention. We present one such case of EUS-FNA of an anterior mediastinal mass, complicated by chylothorax. CASE PRESENTATION: A 60-year-old female with a past medical history significant for COPD, diabetes, depression,90 pack-years of smoking, and a history of stage IIA adenocarcinoma of the appendix treated with colon resection 11 years prior, presented with an enlarged spiculated nodule in the left upper lung lobe noted on an annual surveillance CT scan. She reported significant weight loss, dyspnea on exertion, malaise, and fatigue for over a year. A PET scan performed 1-year prior revealed stable bilateral lung nodules without any hypermetabolic activity. At presentation, she was afebrile, hemodynamically stable, and saturating above 90% on room air. Her physical exam and labs were unremarkable. The large spiculated left upper lobe nodule noted on the CT thorax was concerning for malignancy and a biopsy was recommended to further characterize the lesion. An EUS-FNA was performed, which confirmed a 13 x 10 mm irregular, homogenous mass & a tissue sample was obtained. The procedure was uneventful without any immediate peri-operative complications. Cytology from the aspirate was notable for primary adenocarcinoma of the lung. Two days after the procedure, the patient developed progressively worsening shortness of breath associated with diminished left-sided breath sounds. An immediate repeat CT scan of the chest identified a new left-sided pleural effusion. A thoracentesis with a chest tube insertion drained approximately 500 ml of milky fluid, diagnostic of a chylothorax. Even after three days of fat-free diet and intravenous antibiotics, she continued to have high output from the chest tube. A Left-sided thoracotomy with a mediastinal lymph node dissection, resection of the upper lobe of the left lung, and talc pleurodesis was performed. This led to improvement of the symptoms in the subsequent days, and the follow-up chest x-ray showed resolution of the effusion. The patient was discharged to follow up for treatment of the lung adenocarcinoma. DISCUSSION: EUS-FNA is a commonly used technique to investigate the mediastinal pathology. The complications rate is as low as 3%[1], and typically includes mediastinitis, pneumonia, pericarditis, sepsis, and hemorrhage [2,3]. Chylothorax is an infrequent complication, with only a handful of cases noted in the literature. CONCLUSIONS: This case highlights chylothorax as a rare and severe complication of EUS-FNA. This also emphasizes the need for meticulous attention to anatomical structures while performing the procedure and the significance of post-operative surveillance. REFERENCE #1: Polkowski M, Larghi A, Weynand B, Boustière C, Giovannini M, Pujol B, Dumonceau J-M: Learning, techniques, and complications of endoscopic ultrasound (EUS)-guided sampling in gastroenterology: European Society of Gastrointestinal Endoscopy (ESGE) Technical Guideline. Endoscopy. 2012, 44:190–206. 10.1055/s-0031-1291543 REFERENCE #2: Mongelli F, FitzGerald M, Cafarotti S, Inderbitzi R: Chylothorax after endoscopic ultrasound with fine-needle aspiration causing migrating appearance of a solitary fibrous tumor of the pleura. Ann. Thorac. Med. 2018, 13:114–6. 10.4103/atm.ATM_340_17 REFERENCE #3: Asano F, Aoe M, Ohsaki Y, et al.: Complications associated with endobronchial ultrasound-guided transbronchial needle aspiration: a nationwide survey by the Japan Society for Respiratory Endoscopy. Respir Res. 2013, 14:50. 10.1186/1465-9921-14-50 DISCLOSURES: No relevant relationships by Abdul Hamid Alraiyes, source=Web Response No relevant relationships by nitish singh nandu, source=Web Response No relevant relationships by Swetha Paduri, source=Web Response No relevant relationships by Preeti Vadlamani, source=Web Response

831 VIDEO PRESENTATION LAPAROSCOPIC PARA-CONDUIT HERNIA REPAIR AFTER MINIMALLY INVASIVE ESOPHAGECTOMY

Abstract The para-conduit hernia is a rare occurrence post minimally invasive esophagectomy. We present a case of asymptomatic para-conduit hernia diagnosed via surveillance CT scan and repaired successfully via a laparoscopic approach. Methods N/A. Results N/A. Conclusion N/A. Video https://drive.google.com/file/d/1v6ePGYbLe6BtI6l6B0nOaihLtXv6Mk-S/view?usp=sharing.

The Development of Hypogonadotropic Hypogonadism After Starting Low Dose Mifepristone for Cushing’s Syndrome

Background: Mifepristone is an antiprogesterone that has been studied in females and has shown central effects including suppressing LH surges. There is a paucity of information about how it effects males. Clinical Case: 65-year-old male with bilateral adrenal macronodular hyperplasia noted on a past surveillance CT scan presented to endocrinology. He had a history of coronary artery disease, type 2 diabetes, obesity, and treated sleep apnea. He had progressively worsening abdominal weight gain, supraclavicular fat pads, thin bruising skin, and hypertension. He had several abnormal 1 mg overnight dexamethasone suppression tests (ACTH 3 & <1 pg/ml and cortisol 10 ug/dL & 11.1 ug/dL). He had several abnormal midnight salivary cortisol tests (109 ng/dL, 147ng/dL, and 152 ng/dL, reference <100 ng/dL). He elected to have medical treatment for his Cushing’s Syndrome after worsening hypertension and several episodes of hypertensive urgency. He was deemed a non-surgical candidate. He was started on mifepristone 300 mg/day and spironolactone 12.5 mg/day given eGFR 47 mL/min/1.73sq m. His mifepristone dose was dropped to 300 mg every other day after he had several episodes of orthostatic hypotension, nausea, and hot flashes. On lower dose mifepristone, his hypertension control improved without orthostatic hypotension or nausea. His hot flashes remained and he developed breast enlargement and tenderness. A repeat testosterone was found to be low, but the rest of his evaluation for gynecomastia was negative otherwise. His pre-treatment am testosterone was 281 ng/dL (normal 250–1100 ng/dL) and post mifepristone treatment am testosterone level was <7 ng/dL. He had suppressed gonadotrophins (LH <0.2 mIU/mL; normal 1.4–7.77 mIU/mL, FSH <0.2 mIU/mL; normal 2.5–17.1 mIU/mL), normal prolactin (PRL 11 ng/mL; normal 2.6–12 ng/mL) and a normal pituitary MRI. Conclusion: This is the first case demonstrating severe hypogonadotropic hypogonadism in a male using low dose mifepristone treatment for mild ACTH independent Cushing’s Syndrome. Reference: Escudero, E. and et al. Mifepristone Is an Effective Oral Alternative for the Prevention of Premature Luteinizing Hormone Surges and/or Premature Luteinization in Women Undergoing Controlled Ovarian Hyperstimulation for in Vitro Fertilization. J Clin Endocrinol Metab. 2005; 90(4):2081–2088.

A Huge Adrenal Incidentaloma With Suspicious Features and a Complete Cure!

Introduction: Adrenal hemangioma is an extremely rare benign vascular tumor occurring in adrenal glands (~0.01%). Its clinical presentation is usually vague and is frequently discovered as an incidentaloma. These tumors are mostly encountered at 40–70 years of age and are twice as common in women. We report a case of a nonfunctioning large adrenal incidentaloma with suspicious features on imaging. This in fact was an adrenal hemangioma diagnosed postoperatively with histopathology. Case Description: Our patient was 76 year old Hispanic male, active smoker, with medical history significant for well controlled Type 2 diabetes, hyperlipidemia and hypertension. He was seen for evaluation and management of an adrenal incidentaloma discovered on iv contrast enhanced CT performed to investigate recurrent hematuria. Imaging of the abdomen and pelvis revealed a posterior bladder mass measuring up to 2.6 cm and 20.1 cm x 17.1 cm x 20.5 cm left adrenal mass with few punctuate calcifications displacing the left kidney and spleen- findings concerning for adrenal cortical carcinoma. The right adrenal gland unremarkable. Given the size of mass and suspicious features hormonal workup was initiated in preparation for surgery. Workup was unremarkable for Pheochromocytoma {24 hour urine metanephrine 124 (nl: 0–300), normetanephrine 440 (nl: 0–400)}, Cushing syndrome {(negative 1 mg overnight dexamethasone suppression test), ACTH 22 (nl: 7—63)} and hyperaldosteronism (Aldosterone 5, renin 0.7). Patient underwent an uncomplicated total radical left adrenalectomy, he had no evidence of invasive disease. Pathology showed a large entirely encapsulated heterogenous adrenal mass weighing 2300 grams with largely solid (80%) and cystic components. There was hemorrhage and extensive infarcts- findings consistent with a Hemangioma. He recovered well. No evidence of adrenal insufficiency was noted on subsequent follow-ups. He had a normal surveillance CT scan at 6 months. Discussion: Adrenal hemangiomas are difficult to differentiate clinically and radiographically from adrenal cortical cancer. They must be evaluated to exclude hormonal hypersecretion and malignancy. Previous case reports hypothesized that adrenal hemangiomas may have functional hypersecretion due to mass effect on the adrenal parenchyma. There was no evidence of this in our patient. These tumors increase in size overtime. Surgical resection is often necessary to rule out any malignant potential and alleviate symptoms secondary to mass effect. Adrenal hemangiomas though rare and must be considered in the differential diagnosis.

Screen-detected solid nodules: from detection of nodule to structured reporting.

Lung cancer screening (LCS) is gaining some interest worldwide after positive results from International trials. Unlike other screening practices, LCS is performed by an extremely sensitive test, namely low-dose computed tomography (LDCT) that can detect the smallest nodules in lung parenchyma. Up-to-date detection approaches, such as computer aided detection systems, have been increasingly employed for lung nodule automatic identification and are largely used in most LCS programs as a complementary tool to visual reading. Solid nodules of any size are represented in the vast majority of subjects undergoing LDCT. However, less than 1% of solid nodules will be diagnosed lung cancer. This fact calls for specific characterization of nodules to avoid false positives, overinvestigation, and reduce the risks associated with nodule work up. Recent research has been exploring the potential of artificial intelligence, including deep learning techniques, to enhance the accuracy of both detection and characterisation of lung nodule. Computer aided detection and diagnosis algorithms based on artificial intelligence approaches have demonstrated the ability to accurately detect and characterize parenchymal nodules, reducing the number of false positives, and to outperform some of the currently used risk models for prediction of lung cancer risk, potentially reducing the proportion of surveillance CT scans. These forthcoming approaches will eventually integrate a new reasoning for development of future guidelines, which are expected to evolve into precision and personalized stratification of lung cancer risk stratification by continuous fashion, as opposed to the current format with a limited number of risk classes within fixed thresholds of nodule size. This review aims to detail the standard of reference for optimal management of solid nodules by low-dose computed and its projection into the fine selection of candidates for work up.