Hypodense Liver Lesions Research Articles

6728 Bilateral Adrenal Hemorrhage: Cause Or Consequence?

Abstract Disclosure: M.N. Rayan: None. R. Horner: None. A. Valenciaga: None. L.E. Ryan: None. Introduction: Before the advent of the CT scan, bilateral adrenal hemorrhage was primarily discovered post-mortem in patients who had succumbed to sepsis, burns, or anticoagulant therapy. Today, non-traumatic hemorrhage is recognized as an infrequent, yet potentially lethal diagnosis causing clinical deterioration in acutely ill patients. Clinical Case: Our patient is a 64-year-old-male with a medical history of Myelodysplastic Syndrome initially presented to an external ED with abdominal pain. CT abdomen revealed hepatomegaly, splenomegaly, and new bilateral adrenal masses—absent in an MRI conducted a year earlier. He was treated conservatively and subsequently discharged. Two weeks later, he returned to the hospital with severe right sided flank pain. His hemoglobin and platelet counts dropped from 11.5 g/dL and 309 K/uL during the previous ED visit to 7.7 g/dL and 80 K/uL, respectively. Additionally, his PT/INR, PTT, fibrinogen, and D-Dimer levels were elevated. A repeat CT scan indicated a significant enlargement of the right adrenal mass, raising suspicion of adrenal hemorrhage. He was appropriately transfused, and a BM biopsy was performed to evaluate for acute transformation of underlying MDS. Cortisol levels were monitored daily for adrenal insufficiency. A complicated hospital course ensued marked by worsening anemia, thrombocytopenia, and coagulopathy, accompanied by high fevers and new-onset atrial fibrillation. Mixing studies showed absence of a factor inhibitor ruling out acquired forms of Hemophilia. Infectious workup including fungal and viral serologies returned negative. A PET scan revealed several small hypermetabolic hypodense liver lesions, and hypermetabolic activity diffusely in the spleen, and adrenal glands leading to suspicion of metastasis. Results of the BM biopsy returned revealing hypercellularity, with aggregates of hemosiderin-laden macrophages replacing the bone marrow space with associated necrosis. Worsening abdominal pain with hematochezia prompted an endoscopy, confirming a diagnosis of metastatic melanoma. Concurrently, seizure activity and altered mentation led to a head CT, revealing new metastatic lesions that confirmed the rapid progression of the disease. Subsequently, the patient was transitioned to comfort care and passed away. Clinical Lesson: It is crucial to review the various causes of adrenal hemorrhage, understand the challenges associated with interpreting adrenal imaging, emphasize the need to monitor adrenal function, and consider the occasional necessity for tissue sampling. In this clinical scenario, metastases with hemorrhage were the most likely etiology. The causes of adrenal hemorrhage are not always apparent; in this presentation, the consequence of the underlying disease state ultimately led to the initial presenting symptom of abdominal pain. Presentation: 6/2/2024

Advancing Differentiation of Hepatic Metastases in Malignant Melanoma through Dual-Energy Computed Tomography Rho/Z Maps.

The aim of this study is to evaluate the diagnostic accuracy of dual-energy computed tomography (DECT)-based Rho/Z maps in differentiating between metastases and benign liver lesions in patients diagnosed with malignant melanoma compared to conventional CT value measurements. This retrospective study included 73 patients (mean age, 70 ± 13 years; 43 m/30 w) suffering from malignant melanoma who had undergone third-generation DECT as part of tumor staging between December 2017 and December 2021. For this study, we measured Rho (electron density) and Z (effective atomic number) values as well as Hounsfield units (HUs) in hypodense liver lesions. Values were compared, and diagnostic accuracy for differentiation was computed using receiver operating characteristic (ROC) curve analyses. Additional performed MRI or biopsies served as a standard of reference. A total of 136 lesions (51 metastases, 71 cysts, and 14 hemangiomas) in contrast-enhanced DECT images were evaluated. The most notable discrepancy (p < 0.001) between measured values and the highest diagnostic accuracy for distinguishing melanoma metastases from benign cysts was observed for the Z (0.992; 95% CI, 0.956-1) parameters, followed by Rho (0.908; 95% CI, 0.842-0.953) and finally HU120kV (0.829; 95% CI, 0.751-0.891). Conversely, when discriminating between liver metastases and hemangiomas, the HU120kV parameters showed the most significant difference (p < 0.001) and yielded the highest values for diagnostic accuracy (0.859; 95% CI, 0.740-0.937), followed by the Z parameters (0.790; 95% CI, 0.681-0.876) and finally the Rho values (0.621; 95% CI, 0.501-0.730). Rho and Z measurements derived from DECT allow for improved differentiation of liver metastases and benign liver cysts in patients with malignant melanoma compared to conventional CT value measurements. In contrast, in differentiation between liver hemangiomas and metastases, Rho/Z maps show inferior diagnostic accuracy. Therefore, differentiation between these two lesions remains a challenge for CT imaging.

SAT059 Metastatic Insulinoma Diagnosed Postpartum

Abstract Disclosure: A. Faber: None. H. Lam: None. R. Simon: None. Introduction: Insulinomas are rare neuroendocrine tumors derived from the beta cells of the pancreas. These tumors generally occur at a rate of four cases per million per year, and they are seen across all demographics. Affected patients present with symptoms of hypoglycemia, including confusion, diaphoresis, and palpitations. Insulinomas occur as single or multiple tumors, and can be benign or malignant. Insulinomas with metastases are defined as malignant. The primary treatment is surgical resection. However, in the case of metastatic insulinomas prognosis can be quite poor with limited treatment options. Case Presentation: A 24-year-old female employed as a nurse with otherwise negative medical history originally presented around 3 months postpartum with epigastric pain which was attributed to gas. Symptoms progressed to include lightheadedness, palpitations, and sweating. She checked her blood glucose during these events and noted it to be consistently in the 30s-40s. She would treat these episodes with food and had short-term improvement in symptoms. She presented to an outside hospital where imaging revealed: hepatomegaly with innumerable hypodense liver lesions, hypo-enhancing pancreatic head lesion, sclerotic focus in T4 vertebral body, as well as multiple enlarged upper abdominal lymph nodes including peripancreatic, porta hepatis, and gastrohepatic. Liver biopsy revealed well-differentiated neuroendocrine tumor, WHO grade 3 likely from a pancreatic primary and chemotherapy was initiated with carboplatin and paclitaxel with some response. However, hypoglycemia became refractory to management with 5% dextrose drip, so she was transferred to our facility for escalation of care. TPN was initiated and dextrose drip was escalated eventually to 40% dextrose. She was also given octreotide, hydrocortisone, and eventually diazoxide. Given degree of tumor burden as well as abdominal ascites and clinical condition, surgery was deemed high risk and not recommended. Tumor board meeting was held and her chemotherapy regimen was changed to Carboplatin/Etoposide/Atezolizumab. She subsequently underwent hepatic artery embolization twice with improvement of hypoglycemia. Despite decreasing dextrose drip requirements by over 50%, patient was unable to be liberated from dextrose infusion and had multiple discussions about management options and prognosis. The patient eventually elected to go home with home hospice. Discussion: Insulinoma diagnosed in pregnancy or shortly after pregnancy is extremely rare. There are only three case reports of malignant insulinoma diagnosed in or after pregnancy. Given the degree of extensive metastases at time of presentation, we expect our patient’s insulinoma was present prior to delivery. Hypoglycemia may have only manifested in the postpartum period when there was decreased levels of placenta-derived counterregulatory hormones. Presentation: Saturday, June 17, 2023

Exploring the Role of MRI in the Detection of Atypical Liver Hemangiomas and Exclusion of Metastases

Background: In this article, we highlight the importance of utilizing multiple imaging modalities, including CT, MRI, and abdominal Doppler ultrasound, to accurately differentiate between atypical liver hemangiomas (LH) and metastases. Case report: We introduce a 57-year-old male patient who presented with severe abdominal pain. Initial CT scan findings showed hypodense liver lesions and a well-defined hypodense mass in the sub-diaphragmatic region, raising suspicion for metastatic liver lesions, and prompting further evaluation. To differentiate between atypical hemangiomas and metastases, an MRI scan was performed, revealing a hyperintense signal on T2-weighted images and a hypointense signal on T1-weighted images, consistent with the characteristics of LH. These characteristic signal intensities aided in ruling out metastatic liver lesions, which typically present with a more solid and homogeneous appearance. Contrast-enhanced MRI played a crucial role in confirming the diagnosis. The liver lesions demonstrated moderate vascularization during the early phase of contrast enhancement, followed by progressive centripetal filling during the portal venous and delayed phases. This enhancement pattern is consistent with the slow flow within the dilated vascular spaces of liver hemangiomas. The lesion in the right liver lobe is almost completely filled with contrast, further supporting the diagnosis of hemangioma. Abdominal Doppler ultrasound can provide additional information regarding the vascularity of liver lesions. In this case, the Doppler examination likely helped to further confirm the presence of a hemangioma, as these lesions typically demonstrate increased vascularity compared to metastatic lesions. Conclusion: The comprehensive imaging evaluation utilizing CT, MRI, and abdominal Doppler ultrasound allowed for the confident differentiation of atypical liver hemangiomas from metastatic liver lesions in this case. This emphasizes the importance of a multimodal imaging approach in cases of liver lesions with overlapping features, leading to improved patient management and outcomes.

Next-generation sequencing proves clonal relationship between two distinguished lung and liver carcinomas by standard histopathology approach

Introduction: Two tumors having different histopathologies at anatomically distinct sites giving the picture of dual primary malignancies. Here we presented a case of two possible primary tumors and one secondary mass. Case Report: A 74-year-old female, active smoker, without personal or family cancer history presented with early satiety and weakness for two months. Systems review was positive for a “raw” feeling in stomach, alleviated with antacids. Vital signs were stable with a negative abdominal exam. Lab showed leukocytosis 24.8 K/uL (3.5–10.8 K/uL) with left shift, microcytic anemia with hemoglobin 6.1 g/dL (12.0–16.0 g/dL), and reactive thrombocytosis 477 K/uL (130–400 K/uL). Contrast-enhanced computed tomography (CT) showed right upper lobe necrotizing cavitating lesion with reactive mediastinal and right hilar lymphadenopathy, two irregular hypodense lesions in pancreatic head and tail without ductal dilation with two irregular hypodense liver lesions. Immunohistochemistry of lung and pancreatic lesions were biopsied through endoscopic ultrasound (EUS), consistent with poorly differentiated squamous cell carcinoma (SCC) with extensive necrosis, which indicates pancreatic masses are likely metastases from the lung. Liver lesion biopsy exhibited high-grade neuroendocrine tumor (NET) with focal necrosis. Next gene sequencing was pursued. Given poor functional status, palliative immunotherapy was offered; however, the patient succumbed to respiratory failure. Conclusion: Given the morphology and immunoprofile, differential diagnosis includes dual primary cancers with one metastasis, or primary SCC with metastasis with neuroendocrine differentiation. Despite having different histopathology and immunophenotype, both lung and liver tumors harbor the same molecular profile even at the variants of unknown significance that show identical mutations. As a result, they are directly related. TP53, RB1, MYCL1, and MEK1 mutations are more prevalent in SCC than NET. Tumor mutation burden values may vary as the tumor clonal structure varies between primary and metastatic sites, with higher rates of monoclonal structure recorded in metastases due to clonal selection, leading to a reduction in overall genetic diversity (“bottlenecking”). This raises the suspicion that the liver tumor is a SCC with neuroendocrine differentiation. The paucity of the specimen and rapid clinical course limited further investigation. Germline testing would have been useful to determine whether these findings are somatic or germline.

P311 First reported case of Cladosporium liver abscess in immunocompromised host

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMBackground: Cladosporium species are ubiquitous, saprobic, dematiaceous fungi that are infrequently associated with human opportunistic infections. They are usually associated with allergic rhinitis, asthma, localized superficial, and deep cutaneous and subcutaneous lesions, but rarely cause disseminated infection, known as phaeohyphomycoses.Case Description: We report a case of Cladosporium liver abscess in an immunocompromised host. A 39-year-old male with a history of multiple sexual partners was newly diagnosed with human immunodeficiency virus and was antiretroviral therapy naïve. He presented with epigastric and right hypochondriac pain, associated with abdominal distension for 3 months. On examination, he was jaundiced with hepatomegaly. Full blood count showed leukocytosis with neutrophilia (TWC 14.3 × 109/l with ANC 11.2 × 109/l). The liver function test shows hyperbilirubinemia with obstructive features. (Total bilirubin 101.9 μmol/l, direct bilirubin 78.8 μmol/l, ALT 87 U/l, AST 168 U/l, ALP 383 U/l, INR: 1.37). Baseline CD4 was 41 cells/ul, and HIV viral load was >10 000 000 copies/mL.CECT 4-phase liver shows enlarged liver with smooth lobulated margin, measured 22.5 cm. Multiple large round hypodense masses of varying sizes were seen scattered in both liver lobes. The largest mass is in segment VII measuring 5.8 × 7.7 × 8.8 cm. Liver biopsy showed evidence of diffuse large B cell lymphoma while tissue fungal culture grew Cladosporium sp. Antifungal susceptibility testing showed a low MIC range for posaconazole, voriconazole, and itraconazole while terbinafine was not tested. Patient received tablet voriconazole 200 mg BD for 3 months. He was also initiated on chemotherapy antiretroviral therapy at the same time with the regime of T. Tenofovir disoproxil fumarate/emtricitabine 1 tablet once daily and tablet dolutegravir 50 mg once daily. A repeated PET-CT done 3 months later during chemotherapy shows residual hypodense liver lesions.Discussion: A wide range of fungi can be found on various human mucosal surfaces, such as lungs, vaginal tract, urinary tract, oral cavity, intestines, and skin. The community of commensal fungi interacts with commensal bacteria and the host. Changes in the commensal fungi have a significant impact on host health and are associated with pathological conditions. Cladosporium was reported as one of the commensal fungi. Reports of invasive Cladosporium infection are extremely rare with variable presentation. There were previous case reports of Cladosporium infection of the central nervous system, lung, and skin but no liver abscess has been reported yet. Fungal hepatic abscesses are not uncommon among immunocompromised hematological malignancy patients, especially those with leukemia and prolonged neutropenia. Azoles, particularly itraconazole, and posaconazole have good activity against Cladosporium species, although voriconazole displayed variable activity. This is consistent with our case whereby itraconazole and posaconazole demonstrate the lowest MIC as compared to voriconazole. However, voriconazole was chosen instead of itraconazole for coverage against the possibility of Aspergillus appearing later. In our case, the patient showed a good response to voriconazole.ConclusionThe choice of antifungal will depend on susceptibility testing, organ involvement, tissue bioavailability, drug-drug interaction, and patients’ clinical risk factors; whereas the duration of treatment is guided by radiological resolution and control of risk factors.

Virtual Noncontrast Imaging of the Liver Using Photon-Counting Detector Computed Tomography: A Systematic Phantom and Patient Study.

The aim of this study was to assess the accuracy of virtual noncontrast (VNC) images of the liver in a phantom and patients using dual-source photon-counting detector computed tomography (PCD-CT). An anthropomorphic abdominal phantom with a liver insert containing liver parenchyma (1.4 mgI/mL) and 19 liver lesions (iodine content 0-5 mgI/mL) was imaged on a clinical dual-source PCD-CT (tube voltage 120 kV) and in the dual-energy mode on a dual-source energy-integrating detector (EID) CT (tube voltage combinations, 80/Sn150 kV, 90/Sn150 kV, and 100/Sn150 kV). Rings of fat-equivalent material were added to the phantom to emulate 3 sizes (small, medium, large). Each setup was imaged at 3 different radiation doses (volume CT dose index: 5, 10, and 15 mGy). Virtual noncontrast images were reconstructed and CT attenuation was measured in each lesion and liver parenchyma. The absolute error of CT attenuation (VNCerror) was calculated using the phantom specifications as reference. In addition, 15 patients with hypodense liver lesions who were clinically scanned on PCD-CT were retrospectively included. Attenuation values in lesions and liver parenchyma in VNC images reconstructed from portal venous phase CT were compared with true noncontrast images. Statistical analysis included analysis of variance with post hoc t tests and generalized linear models to assess the impact of various variables (dose, patient size, base material, iodine content, and scanner/scan mode) on quantification accuracy. In the phantom, the overall mean VNCerror for PCD-CT was 4.1 ± 3.9 HU. The overall mean VNCerror for EID-CT was 7.5 ± 5, 6.3 ± 4.7, and 6.7 ± 4.8 HU for 80/Sn150 kV, 90/Sn150 kV, and 100/Sn150 kV, respectively, with the VNCerror of EID-CT being significantly higher at all tube voltage settings (P < 0.001), even after adjusting for dose, size, iodine content of the lesion, and attenuation of base material. For PCD-CT, a smaller phantom size was associated with higher quantification accuracy (P = 0.007-0.046), whereas radiation dose did not impact accuracy (P > 0.126). For EID-CT, but not for PCD-CT, VNCerror increased with lesion iodine content (P < 0.001). In patients, there was no difference in attenuation measured on true noncontrast and VNC images (P = 0.093), with a mean VNCerror of 3.7 ± 2.2 HU. Photon-counting detector CT allows for the reconstruction of VNC images of the liver both in a phantom and in patients with accurate attenuation values, being independent of dose, attenuation of base material, and liver iodine content.

Quantum Iterative Reconstruction for Abdominal Photon-counting Detector CT Improves Image Quality.

Background An iterative reconstruction (IR) algorithm was introduced for clinical photon-counting detector (PCD) CT. Purpose To investigate the image quality and the optimal strength level of a quantum IR algorithm (QIR; Siemens Healthcare) for virtual monoenergetic images and polychromatic images (T3D) in a phantom and in patients undergoing portal venous abdominal PCD CT. Materials and Methods In this retrospective study, noise power spectrum (NPS) was measured in a water-filled phantom. Consecutive oncologic patients who underwent portal venous abdominal PCD CT between March and April 2021 were included. Virtual monoenergetic images at 60 keV and T3D were reconstructed without QIR (QIR-off; reference standard) and with QIR at four levels (QIR 1-4; index tests). Global noise index, contrast-to-noise ratio (CNR), and voxel-wise CT attenuation differences were measured. Noise and texture, artifacts, diagnostic confidence, and overall quality were assessed qualitatively. Conspicuity of hypodense liver lesions was rated by four readers. Parametric (analyses of variance, paired t tests) and nonparametric tests (Friedman, post hoc Wilcoxon signed-rank tests) were used to compare quantitative and qualitative image quality among reconstructions. Results In the phantom, NPS showed unchanged noise texture across reconstructions with maximum spatial frequency differences of 0.01 per millimeter. Fifty patients (mean age, 59 years ± 16 [standard deviation]; 31 women) were included. Global noise index was reduced from QIR-off to QIR-4 by 45% for 60 keV and by 44% for T3D (both, P < .001). CNR of the liver improved from QIR-off to QIR-4 by 74% for 60 keV and by 69% for T3D (both, P < .001). No evidence of difference was found in mean attenuation of fat and liver (P = .79-.84) and on a voxel-wise basis among reconstructions. Qualitatively, QIR-4 outperformed all reconstructions in every category for 60 keV and T3D (P value range, <.001 to .01). All four readers rated QIR-4 superior to other strengths for lesion conspicuity (P value range, <.001 to .04). Conclusion In portal venous abdominal photon-counting detector CT, an iterative reconstruction algorithm (QIR; Siemens Healthcare) at high strength levels improved image quality by reducing noise and improving contrast-to-noise ratio and lesion conspicuity without compromising image texture or CT attenuation values. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Sinitsyn in this issue.

S2745 Chronic Lymphocytic Leukemia: An Unusual Cause of Hepatic Granulomas

Introduction: Hepatic granulomas (HG) are localized collections of inflammatory cells, found in 2 to 10% of patients who undergo liver biopsy. HG has a wide differential and, in some cases, may not lead to a definitive diagnosis. We present a rare case of chronic lymphoid leukemia (CLL) presenting as HG. Case Description/Methods: 70-year-old male with past history of CLL presented with fever, chills and night sweats for 2 weeks. Admission labs were significant for WBC count 25 and elevated LFTs with total bilirubin 3.67, Alkaline phosphatase 281, AST 41 and ALT 144. CT liver protocol showed diffuse hypodense liver lesions, classified as LIRADs 3 indeterminate lesions. MRI was contraindicated due to incompatible hardware. Infectious work up including cultures, viral and tick serologies, and acute and chronic liver serologies were negative and patient was observed off antibiotics and discharged. Subsequent liver biopsy revealed nodules of necrotizing granulomas but negative for CLL, Richter transformation, fungal or TB on special stains. Work up was expanded to rule out autoimmune causes, fungal, atypical viral, TB infections, hemochromatosis and sarcoidosis as a cause of HG, all of which resulted negative. Due to unclear diagnosis and persistent abnormal liver imaging, repeat liver biopsy was performed which revealed periportal and sinusoidal atypical lymphoid infiltrate with necrotizing granulomatous inflammation. Flow cytometry showed small CD 19+ B cells, consistent with CLL. This upstaged patient’s disease to Rai stage 2 and he was started on chemotherapy, which normalized LFTs and improved symptoms. Discussion: HG remains a diagnostic challenge for many clinicians. Common malignancies associated with hepatic granulomas are lymphoma, renal cell carcinoma and liver metastasis. CLL is not a well defined cause of hepatic granuloma. Other causes include drugs, bacterial, fungal, viral or parasitic infections, autoimmune disorders, TB and sarcoidosis. The histologic subtypes (caseating vs non caseating) may give a clue to the diagnosis. Progressive fibrosis, portal hypertension, and cirrhosis can rarely develop if not identified early. In patients with CLL, liver involvement may upstage the disease, necessitating more aggressive treatment. Assessment for associated clinical symptoms, targeted lab and radiological investigations, and characterization of the morphology and localization of granulomas will usually lead to a definitive diagnosis and appropriate treatment.

Virtual Monoenergetic Images of Dual-Energy CT-Impact on Repeatability, Reproducibility, and Classification in Radiomics.

Simple SummaryVirtual monoenergetic images from dual-energy CT are incrementally used in routine clinical practice. Thus, radiomic analysis will be more often performed on these images in the future. This study characterized the test–retest repeatability and reproducibility of radiomic features from virtual monoenergetic images and their impact on machine-learning-based lesion classification. The results of this study provide a basis to improve radiomic analyses and identify the role of feature stability in classification tasks when using virtual monoenergetic imaging with different scan or reconstruction parameters in multicenter clinical studies.The purpose of this study was to (i) evaluate the test–retest repeatability and reproducibility of radiomic features in virtual monoenergetic images (VMI) from dual-energy CT (DECT) depending on VMI energy (40, 50, 75, 120, 190 keV), radiation dose (5 and 15 mGy), and DECT approach (dual-source and split-filter DECT) in a phantom (ex vivo), and (ii) to assess the impact of VMI energy and feature repeatability on machine-learning-based classification in vivo in 72 patients with 72 hypodense liver lesions. Feature repeatability and reproducibility were determined by concordance–correlation–coefficient (CCC) and dynamic range (DR) ≥0.9. Test–retest repeatability was high within the same VMI energies and scan conditions (percentage of repeatable features ranging from 74% for SFDE mode at 40 keV and 15 mGy to 86% for DSDE at 190 keV and 15 mGy), while reproducibility varied substantially across different VMI energies and DECTs (percentage of reproducible features ranging from 32.8% for SFDE at 5 mGy comparing 40 with 190 keV to 99.2% for DSDE at 15 mGy comparing 40 with 50 keV). No major differences were observed between the two radiation doses (<10%) in all pair-wise comparisons. In vivo, machine learning classification using penalized regression and random forests resulted in the best discrimination of hemangiomas and metastases at low-energy VMI (40 keV), and for cysts at high-energy VMI (120 keV). Feature selection based on feature repeatability did not improve classification performance. Our results demonstrate the high repeatability of radiomics features when keeping scan and reconstruction conditions constant. Reproducibility diminished when using different VMI energies or DECT approaches. The choice of optimal VMI energy improved lesion classification in vivo and should hence be adapted to the specific task.

Patient with H syndrome, cardiogenic shock, multiorgan infiltration, and digital ischemia

BackgroundH syndrome (HS) is a rare autoinflammatory disease caused by a mutation in the solute carrier family 29, member 3 (SCL29A3) gene. It has a variable clinical presentation and little phenotype-genotype correlation. The pathognomonic sign of HS is cutaneous hyperpigmentation located mainly in the inner thighs and often accompanied by other systemic manifestations. Improvement after tocilizumab treatment has been reported in a few patients with HS. We report the first patient with HS who presented cardiogenic shock, multiorgan infiltration, and digital ischemia.Case presentation8-year-old boy born to consanguineous parents of Moroccan origin who was admitted to the intensive care unit during the Coronavirus Disease-2019 (COVID-19) pandemic with tachypnoea, tachycardia, and oliguria.Echocardiography showed dilated cardiomyopathy and severe systolic dysfunction compatible with cardiogenic shock. Additionally, he presented with multiple organ dysfunction syndrome. SARS-CoV-2 polymerase chain reaction (PCR) and antibody detection by chromatographic immunoassay were negative.A previously ordered gene panel for pre-existing sensorineural hearing loss showed a pathological mutation in the SCL29A3 gene compatible with H syndrome.Computed tomography scan revealed extensive alveolar infiltrates in the lungs and multiple poor defined hypodense lesions in liver, spleen, and kidneys; adenopathy; and cardiomegaly with left ventricle subendocardial nodules.Invasive mechanical ventilation, broad antibiotic and antifungal coverage showed no significant response. Therefore, Tocilizumab as compassionate use together with pulsed intravenous methylprednisolone was initiated. Improvement was impressive leading to normalization of inflammation markers, liver and kidney function, and stabilising heart function. Two weeks later, he was discharged and has been clinically well since then on two weekly administration of Tocilizumab.ConclusionsWe report the most severe disease course produced by HS described so far in the literature. Our patient’s manifestations included uncommon, new complications such as acute heart failure with severe systolic dysfunction, multi-organ cell infiltrate, and digital ischemia.Most of the clinical symptoms of our patient could have been explained by SARS-CoV-2, demonstrating the importance of a detailed differential diagnosis to ensure optimal treatment.Although the mechanism of autoinflammation of HS remains uncertain, the good response of our patient to Tocilizumab makes a case for the important role of IL-6 in this syndrome and for considering Tocilizumab as a first-line treatment, at least in severely affected patients.

Aggressive primary gastric lymphoma (PGL) masquerading as hepatocellular cancer (HCC) in alcoholic cirrhosis

BackgroundThe gastrointestinal tract is sa well-known site for extranodal Non-Hodgkin lymphomas, with the stomach is known to be the most common site on lymphoma, primary gastric lymphoma (PGL). The lymphoproliferative disorder rarely occurs in patients with cirrhosis. We report a unique case of metastatic PGL in a patient with cirrhosis.Case presentationA middle-aged male with decompensated alcoholic cirrhosis presented with two weeks of epigastric abdominal pain, abdominal distension, and jaundice. Abdominal triple-phase CT scan was consistent with cirrhosis, ascites, and multiple new hypodense liver lesions classified as an intermediate probability for HCC based on the LI-RADS classification system (LI RADS 3). Due to the CT findings in the setting of cirrhosis, a provisional diagnosis of HCC was made. Upper endoscopy revealed new multiple umbilicated submucosal nodules in the gastric body. Biopsy and immunostaining consistent with high-grade B-cell lymphoma. Targeted liver biopsy with similar morphology and immunostaining profile consistent with metastatic primary gastric DLBCL.ConclusionsThe case highlights the importance of recognizing metastatic PGL in patients with underlying cirrhosis to differentiate lymphoma from hepatocellular cancer. Targeted liver biopsies with lymphoma immunostaining are required to make a diagnosis.

Should We Report Incidental Low-Density Liver Lesions with Benign Features? A Retrospective Single-Center Analysis of Trauma CT Scans

Abstract Background Many incidental liver lesions are benign and require no additional workup. Investigation of such lesions can have a negative impact of both the patient and health care system. However, the impact of how radiologists report these incidental lesions is not clear. We aimed to investigate how reporting of incidental liver lesions on trauma computed tomography (CT) scan affects follow-up. Methods This is a retrospective single-center analysis of body CT scans performed following abdominal trauma. Information was collected on the reporting of incidental low-density liver lesions and any additional imaging performed. Results A total of 3,595 trauma body CT scan reports were reviewed. Incidental liver lesions were identified in 527 (15%) patients, with 347 (10%) fulfilling the inclusion criteria. Additional imaging was requested by the referring doctor for 43 out of 285 patients (15%) when lesions were mentioned in the body of the report only, compared with 41 out of 62 patients (66%) when mentioned in the conclusion (odds ratio [OR] = 10.99, p &lt; 0.0001). When additional imaging was recommended in the report, follow-up was arranged for 36 out of 52 patients (69%), compared with 48 out of 285 patients (16%) when it was not suggested (OR = 11.58, p &lt; 0.0001). Additional imaging was requested for 84 of the 347 patients (24%), with 24 of these performed at our institution. All patients followed-up at our institution were diagnosed with a benign lesion. Conclusion Reporting incidental hypodense liver lesions in the conclusion or specifically recommending further additional imaging, both led to significantly increased likelihood of additional imaging being performed. Radiologists who encounter such lesions should consider excluding them from the conclusion if there are no malignant features or patient risk factors.

S2466 Homomorphic Adenocarcinoma Metastases to the Liver: A Report of Two Cases

INTRODUCTION: Classifying a malignant lesion as primary or metastatic can be challenging in some cases. However, identifying the underlying primary disease is crucial for guiding therapy. We describe two cases of liver lesions of unclear etiology that were ultimately determined to be from metastatic adenocarcinoma originating in the ampulla (Case 1) and the colon (Case 2) and were curiously “homomorphic” in appearance. That is, their radiographic appearances resembled a dilated tubular structure akin to the ampulla and a haustrated bowel akin to the colon, respectively. Tumor homomorphism is a relatively new concept utilizing visual similarities to aid in determining an uncertain primary source of metastatic disease. CASE DESCRIPTION/METHODS: Case 1: A 51-year-old male who presented with dyspnea and right upper quadrant abdominal pain underwent computed tomography (CT) of the abdomen, revealing a solitary, 6 cm, cystic lesion in the liver, reminiscent of an ampulla anatomically (Figure 1). Percutaneous biopsy showed adenocarcinoma with signet-ring features of unknown primary. An obstructive mass was seen by endoscopy in the region of the major duodenal papilla. Endoscopic biopsy confirmed tumor cells with signet ring features and a mucinous background (Figure 2). Immunohistochemical evaluation was positive for BerEP4, consistent with signet-ring adenocarcinoma. Case 2: A 46-year-old male presented with five months of generalized abdominal pain, weight loss, constipation, and recent vomiting. CT of the abdomen and pelvis demonstrated numerous hypodense liver lesions. Percutaneous biopsy of the liver lesions revealed malignant glands positive for CK20 and CDX2 and negative for CK7, consistent with intestinal-type adenocarcinoma, suggestive of colorectal primary. On further review of the CT images, annular thickening of the rectosigmoid junction was noted, and the liver lesions were reminiscent of colon, being capacious with haustra-like septations (Figure 3). Colonoscopy revealed a firm, malignant appearing lesion at the rectosigmoid junction. DISCUSSION: The liver is a common site of tumor metastasis. While numerous diagnostic modalities can help detect the primary malignancy, they are often costly, time-consuming, invasive, and may still be inconclusive. Hence, as recently reported in hollow viscous organs and as illustrated here in the context of the liver, the presence of tumor homomorphism may allow clinicians to visually link a metastatic lesion to its primary source, thus providing a unique diagnostic clue.Figure 1.: Computed tomography (CT) scan depicting a 6 cm, ampulla-like, cystic appearing hypodense left hepatic lobe lesion with bile duct and periampullary thickening resulting in mass effect and consequent duodenal stenosis.Figure 2.: Ancillary studies on cytology specimen illustrating malignant cells with signet ring features.Figure 3.: Computed tomography (CT) scan of the abdomen and pelvis illustrating liver metastasis reminiscent of a sigmoid colon anatomically delineating the concept of homomorphism.

MON-902 Etomidate - an Under Utilized but Safe and Efficacious Drug to Treat Acute Severe Cushing’s Syndrome- Case Reports of Ectopic ACTH Syndrome from Neuroendocrine Malignancies

Background: Intravenous etomidate infusion, in non-hypnotic doses, rapidly lowers cortisol levels by blocking 11-beta hydroxylation of deoxycortisol to inhibit cortisol production. It is an underutilized drug due to concerns of excess sedation and ICU monitoring. Clinical Case 1: A 44 year-old female with HTN, diabetes, and recently diagnosed pancreatic neuroendocrine tumor with liver metastases presented with altered mentation. Labs showed severe hypokalemia, metabolic alkalosis, serum AM cortisol >60.2 ug/dL (n 6.7-22.6 ug/dL), ACTH of 698.1 pg/mL (n 7.2-63.3 pg/mL), 24-hour urine free cortisol (UFC) of 5791 ug/24hr (n 5-64 ug/24hr), midnight salivary cortisol of 8.04 ug/dL (n <0.01-0.09), and abnormal low dose (LDDST) and high dose (HDDST) dexamethasone suppression tests each with cortisol >60.2 ug/dL. She developed worsening psychosis, likely secondary to hypercortisolism. After ICU transfer, etomidate infusion was initiated at 2.5 mg/hr and titrated upward, leading to rapid drop in cortisol levels and concomitant improvement in mentation. No respiratory or airway difficulties developed. Ketoconazole and metyrapone were started and etomidate was weaned off. Steroids were added once cortisol levels fell below 10 ug/dL as part of “block and replace.” The patient eventually underwent bilateral adrenalectomy with improvement in hemodynamic and blood glucose parameters. She was discharged on physiologic replacement doses of hydrocortisone and fludrocortisone, with no reported issues two months later. Clinical Case 2: A 51 year-old man with one month of hematochezia presented with hypertension, severe hypokalemia, metabolic alkalosis, and QTc prolongation. Colonoscopy was unremarkable; however, labs revealed a cortisol of 43.1 ug/dL, ACTH of 83.6 pg/mL, and 24-hour UFC of 7,494 ug/L, with an abnormally elevated LDDST. Imaging showed a pancreatic mass and multiple hypodense liver lesions. The overall presentation was suggestive of ectopic ACTH syndrome due to metastatic neuroendocrine carcinoma, which was confirmed on biopsy. Chemotherapy, ketoconazole, and metyrapone inadequately lowered cortisol. Etomidate drip was initiated at 3 mg/hr in the ICU, with rapid reduction in cortisol levels to <20 ug/dL without respiratory compromise. Attempts to wean off etomidate were unsuccessful and the patient underwent bilateral adrenalectomy. The surgery was compromised due to extensive liver and pancreatic enlargement, and follow up imaging revealed incomplete resection. 8am cortisol level (off etomidate) was >60.0 ug/dL. Metyrapone and ketoconazole were resumed and hydrocortisone was later initiated for “block and replace”. The patient remains in critical condition. Conclusion: Etomidate-in non- hypnotic doses is useful for the rapid lowering of cortisol levels.

3189 Portal Vein Thrombosis Without Cirrhosis: A Case Report

INTRODUCTION: PVT is a rare entity in the absences of liver cirrhosis, malignancy, prothrombotic disorder or an intra-abdominal inflammatory state. In some cases, no clear etiology can be found and it can be triggered by a combination of factors. We report a case of non-cirrhotic woman with a symptomatic and progressive PVT in the setting of low antithrombin activity and liver lesions. CASE DESCRIPTION/METHODS: 48 year old female without past medical or family medical history, was brought to the ED with diffuse abdominal pain. For the past ten weeks, she has experienced post-pandrial abdominal pain associated with nauseas and two episodes of non-bloody vomiting. She denied diarrhea, recent abdominal infections, drug use or OCP use. Patient has not undergone abdominal surgery. Her physical exam was unremarkable except for mild diffuse abdominal pain, no Murphy's sign, no guarding or rebound signs. CBC, BMP, lipase and liver function panel was unremarkable. Recent mammography, EGD and colonoscopy displayed no signs of malignancy or portal hypertension. MRA showed no stenosis or obstruction of arteries. CAT-scan of abdomen and pelvis with IV contrast showed extensive thrombosis of main portal vein, right portal vein, left portal vein and the portosplenic confluence. Also showed collateral vessels extending from the portosplenic confluence into the bilateral retroperitoneum, bilateral renal hilum and extending across the ovarian veins into the pelvis. There were multiple indeterminate hypodense liver lesions. Additional laboratory tests were ordered and samples collected before starting anticoagulation. Laboratory tests showed decrease antithrombin activity, which is a risk factor for PVT. She was admitted on low-molecular weight heparin (LMWH) until stabilization, and then discharged on oral anticoagulation. In this case, outpatient follow up evaluation by hemato-oncology was scheduled to rule out other coagulation disorders and malignancy. DISCUSSION: PVT in a healthy and young patient is not common. The prevalence of PVT is low in patients with cirrhosis; it is even lower in patients non-cirrhotic and without malignancy. It has been estimated that in non-cirrhotic PVT, hypercoagulable states account for 40%-60% of cases. The American Association for the Study of Liver Diseases (AASLD) guidelines recommend treatment with anticoagulation to prevent thrombi extension and to restore blood flow in occluded vessels. The outcome for non-cirrhotic, non-malignant PVT is good if the diagnosis and treatment occurs early.

1458 Colon Cancer Metastatic to the Pancreas Presenting as DKA

INTRODUCTION: New onset diabetes mellitus (DM) in the setting of a pancreatic mass has been described, primarily with adenocarcinomas, due to the secretion of diabetogenic substances. DM related to pancreatic metastases is rarely seen. We present a case of colon cancer metastatic to the pancreas presenting as diabetic ketoacidosis (DKA). CASE DESCRIPTION/METHODS: A 69-year-old male with a 70 pack-year tobacco history and hypertension presented to the emergency department with fatigue, weight loss, and abdominal pain. Laboratory tests demonstrated a white blood cell count of 11.8 109/L, a hemoglobin of 8.0 g/dL, sodium of 125 mmol/L, carbon dioxide of 18 mmol/L, and a glucose of 656 mg/dL with positive serum ketones indicating diabetic ketoacidosis. He was admitted to the hospital and treated with insulin and IV crystalloids. A chest x-ray showed multiple lung nodules. A CT scan of the chest, abdomen, and pelvis revealed bilateral lung masses, an uncinate process pancreatic mass, multiple hypodense liver lesions, and thickening of the sigmoid colon. Bronchoscopy was performed and cytology revealed metastatic adenocarcinoma with suspected source of colonic, hepatobiliary, or upper gastrointestinal source. EUS/FNA was performed on the pancreatic mass and demonstrated poorly differentiated carcinoma of unclear primary source. Flexible sigmoidoscopy discovered a friable mass in the sigmoid colon. Biopsies were taken revealing adenocarcinoma on the background of high grade dysplasia consistent with a primary colon cancer. Given the widely metastatic nature of his disease he was offered FOLFOX + Bevacizumab as well as a palliative care referral. DISCUSSION: The majority of malignant pancreatic lesions are primary pancreatic tumors, with a small percentage due to metastases. The most common tumor to metastasize to the pancreas is renal cell carcinoma. Few cases of metastatic colon cancer to the pancreas have been reported. DKA as a first presentation of pancreatic adenocarcinoma is a very rare phenomenon with more typical presenting symptoms including abdominal pain, nausea and jaundice. Our case features two rare findings; metastatic colon cancer to the pancreas and DKA as the initial presentation of a pancreatic mass. This highlights the need to consider uncommon metastatic lesions in cases of symptomatic pancreatic masses.

2617 Duodenal Leiomyosarcoma: A Rare Cause of Gastric Outlet Obstruction

INTRODUCTION: Intestinal leiomyosarcoma (LMS) is a rare cancer comprising 0.2% of all malignant tumors and involves the ileum in nearly half of cases. The remainder occur in the proximal duodenum and jejunum primarily, or metastatically from non-intestinal sites such as the uterus. We report this case of primary duodenal LMS complicated by gastric outlet obstruction. CASE DESCRIPTION/METHODS: A 57 year old woman presented with a two month history of worsening epigastric and right upper quadrant pain without nausea, vomiting, weight loss, or altered bowel habits. On physical exam she had marked epigastric tenderness. Abdominal contrast CT demonstrated multiple hypodense liver lesions measuring up to 2cm and a mildly dilated and thickened descending segment of the duodenum. Laboratory evaluation including tumor markers was normal. Without a clear primary malignancy source, the patient underwent percutaneous liver biopsy. Histopathology revealed high grade smooth muscle sarcoma, which stained positively for desmin, SMA, CD 57, and CD 34. Chemotherapy with gemcitabine and docetaxel was initiated per oncology. Within weeks, the patient developed worsening abdominal pain, nausea, and vomiting. CT imaging showed a mass projecting over the descending duodenum causing gastric outlet obstruction. After nasogastric decompression, the patient underwent an EGD. A friable, circumferential mass was seen emanating from distal duodenal bulb extending proximally to the second portion. A duodenal self expanding metal stent was inserted from just proximal to the ampulla to the distal antrum, effectively bridging the mass. Biopsy of the mass was consistent with high grade sarcoma, identical to the liver biopsy. Upper GI contrast series confirmed stent patency; patient tolerated an appropriately advanced diet, and was discharged home to continue outpatient chemotherapy. DISCUSSION: Based on our literature review, there have been no documented cases of gastric outlet obstruction secondary to duodenal LMS. Such tumors often present with abdominal pain and bleeding due to their highly vascular nature. In general, small intestinal malignancies are rare and often difficult to diagnose due to non-specific symptomatic progression resulting in delayed evaluation. Disease is often advanced to lymphatic spread or metastasis at diagnosis as was the case in our patient. A broad differential diagnosis should be considered in patients with unclear primary malignancies presenting with obstructive symptoms.

Evaluation of Adaptive Statistical Iterative Reconstruction-V Reconstruction Algorithm vs Filtered Back Projection in the Detection of Hypodense Liver Lesions: Reader Performance and Preferences.

The aim of the study was to evaluate diagnostic accuracy and readers' experience in the detection of focal liver lesions on computed tomography with Adaptive Statistical Iterative Reconstruction-V (ASIR-V) reconstruction compared with filtered back projection (FBP) scans. Fifty-five patients with liver lesions had FBP and ASIR-V scans. Two radiologists independently reviewed both sets of computed tomography scans, identifying and characterizing liver lesions. Adaptive Statistical Iterative Reconstruction-V scans had a reduction in dose length product (P < 0.0001) with no difference in image contrast (P = 0.1805); image noise was less for the ASIR-V scans (P < 0.0001) and contrast-to-noise ratio was better for ASIR-V (P = 0.0002). Both readers found more hypodense liver lesions on the FBP (P = 0.01) scans. Multiple subjective imaging scores were significantly less for the ASIR-V scans for both readers. Although ASIR-V scans were objectively better, our readers performed worse in lesion detection on them, suggesting a need for better education/experience with this technology during implementation.

Incidental detection of endometriosis with 18F-fluorodeoxyglucose positron emission tomography-computed tomography in a patient with cervical intraepithelial neoplasia and adenomyosis

Endometriosis is commonly associated with chronic pelvic pain and its presentation varies between individuals. The only way to confirm the presence of endometriosis is via keyhole or open surgery. In the presence of hematuria, deep endometriotic infiltration needs to be considered. We share an interesting case highlighting the role of 18F-fluorodeoxyglucose positron emission tomography-computed tomography in evaluating a posterior urinary bladder wall lesion and hypodense liver lesions in a middle-aged woman with presenting with frank hematuria in the background of treated cervical intraepithelial neoplasia and adenomyosis.