ECP 2023 Abstracts

S218 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 *Pathology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bolo- gna, Bologna, Italy., School of Anatomic Pathology, Department of Biomedical and Neuromotor Sciences, University of Bologna, Italy Background & objectives: The growing technologies in Albumin in situ hybridization (ISH) have changed the sensitivity and the routine application in the diagnosis of hepatic malignancies. Our aim was to assess the diagnostic accuracy of Albumin ISH with RNAscope® on different cholangiocarcinoma subtypes. Methods: Forty-five cholangiocarcinoma (CCA) patients were retro- spectively selected: 29 intrahepatic (15 small-duct and 14 large-duct subtypes), 7 peri-hilar and 9 extrahepatic. Histology was revised in all cases, and Albumin ISH was performed with the RNAscope® chromo- genic detection kit, followed by a semiquantitative assessment of the percentage of positive cells on high-magnification fields. Results: Albumin ISH gave substantial different results according to CCA localization (p<0.001, Kruskal-Wallis test): it was always negative in extrahepatic CCAs, only one peri-hilar case was positive, and any level of positivity was observed in 25/29 (86.2%) intrahe- patic CCAs, with a mean number of positive cells of 25.5± 29.3%. In intrahepatic CCAs we noticed significant differences according to the subtype: mean cell positivity was 38.8±29.8% in small-duct and 11.4±21.9 in large-duct CCAs respectively (p=0.003, Mann-Whitney test). With a ROC curve we evaluated a 5% cut-off of Albumin-positive cells: 12/15 (80.0%) small-duct and 3/14 (21.4%) large-duct CCAs showed >5% positivity (p=0.002, chi-square test; odd-ratio 14.7). Conclusion: Albumin mRNA detected with the past methodologies used to show a scant and irregular positivity in biliary lesions. The introduction of more sensitive techniques has changed the indica- tions for ISH, since most intrahepatic CCAs of the small-duct sub- type shows a significant number of positive cells. Albumin positivity decreases from liver periphery to the large ducts, suggesting that ISH can be helpful in the differential diagnosis between small-duct and large-duct CCAs, as well as between intrahepatic large-duct CCAs and metastases. E-PS-07-003 Significance of more than mild portal/periportal inflammation and bile duct injury in non-alcoholic fatty liver disease (NAFLD) D. Allende*, C. Guy, D. Kleiner, R. Gill, D. Carpenter, O. Cum- mings, M. Contos, M. Yeh, P. Belt, L. Wilson, C. Behling *Cleveland Clinic GME, USA Background & objectives: Portal inflammation (PI) in NAFLD is linked to fibrosis and 30% of cases have positive. Bile duct injury (BDI) and portal/periportal inflammation (PI/PPI) raise concerns for superim- posed diseases. The study aims to determine the significance of these findings in NAFLD. Methods: Adult liver biopsies from NAFLD cases (2017-2022) were scored included. “Moderate” (inflammation covers portal matrix) or “severe” (“moderate” and expands portal tracts) PI cases were com- pared to “none-mild” PI. “Moderate” (1/3-2/3 of the portal circum- ference) or “severe” (> 2/3 of circumference) PPI cases were “none- mild” PPI. PI, PPI, and BDI were analysed in relation to histologic and clinical data. Results: 118/422 (28%) showed moderate/severe PI, 2/422 (0.5% of cohort) fulfilled criteria for PBC (positive AMA and BDI). Inci- dentally found BDI (n:20) had a lower NAS (p=0.001) and were less likely to have nonalcoholic steatohepatitis (NASH) (P=0.004). 70/422 (17%) had moderate/severe PPI. No statistically significant difference was seen between these cases and those with none/mild PPI in relation to autoantibodies (ANA, AMA, ASMA) expression, aminotransferases, NAS or diagnosis of NASH. In 33/70 (47%), ANA and/or ASMA were positive. Among patients with moderate/severe PPI, 8/70 (11% or 1.9% of the cohort) both ANA and ASMA were expressed, raising greater consideration for AIH. Moderate/severe PPI was associated with higher fibrosis stage (p= 0.0007). Conclusion: Incidentally found PBC was extremely rare in our NAFLD cohort (0.5%), yet confirmatory AMA testing may be helpful if BDI is noted. Prominent PPI was noted in 17% of NAFLD cases scored with the expanded portal changes scoring system. About 11% of patients of our NAFLD cases had moderate/severe PPI and positive ANA/ASMA autoantibodies which highlights the importance of excluding AIH or drug injury in this enriched subset. Funding: The Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) is supported by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) (grants U01DK061713, U01DK061718, U01DK061728, U01DK061732, U01DK061734, U01DK061737, U01DK061738, U01DK061730, U24DK061730). Additional support is received from the National Center for Advancing Translational Sciences (NCATS) (grants UL1TR000439, UL1TR000077, UL1TR000436, UL1TR000150, UL1TR000424, UL1TR000006, UL1TR000448, UL1TR000040, UL1TR000100, UL1TR000004, UL1TR000423, UL1TR002649, UL1TR000454). This research was supported in part by the Intra- mural Research Program of the NIH, National Cancer Institute. The authors thank the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) for its support of the NASH CRN and this research. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. E-PS-07-004 Different kinds of embolization in advanced carcinomas: a review of literature, visual comparison and possible complications M. Alzamora*, J. Castro, M. Hanbazazh, M. Jácome *IPO-Porto, Portugal Background & objectives: Trans-arterial chemoembolization (TACE) and selective internal radiation therapy (SIRT) are novel therapies for unresectable liver masses, including colorectal liver metastasis (LM). We aim to review possible complications of these therapies and provide a visual comparison of different types of beads. Methods: We present three cases of metastatic colorectal cancer (mCCR) with LM. Patient 1 underwent TACE with irinotecan; he died within 48 hours and an autopsy was performed. Patient 2 underwent TACE with PVA; he was submitted to hemicolec- tomy and metastasectomy. Patient 3 underwent SIRT with Yttrium-90 (Y-90); she later devel- oped sudden epigastric pain and performed upper endoscopy with biopsies. Results: Cause of death for patient 1 was determined as necrotizing acute pancreatitis (NAP) of embolic cause due to regurgitation of iri- notecan beads. A 4cm hepatic nodule was identified and the pancreas exhibited haemorrhagic necrosis. On histology, there were numerous intravascular reddish inframillimetric microspheres occluding vessels on multiple organs. Patient 2 presented with no complications associated with treatment. A yellow-ish intravascular material was observed throughout the liver specimen, corresponding, on histology, to a basophilic material com- patible with PVA. Patient 3 presented with treatment-associated gastritis, and histo- pathologic examination revealed unspecific ischemic and regenerative