ECP 2023 Abstracts

S224 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 Methods: We included all primary liver consult cases received in our Department between October 2016 and December 2022. Data on the sender (hepatologist/pathologist/patient) and the reason for consult were collected. Initial and consult reports were screened for adequacy of clinical/laboratory/imaging information received, stains performed, final diagnosis, disease grading/staging and comment on aetiology with suggestions to the clinician, where appropriate. Results: We retrieved 219 liver consults, 187(85.4%) submitted by hepatologists. For medical cases (n=147,67.1%), most common initial diagnoses were non-specific changes (n=37,25.2%), chronic hepati- tis (n=17,11.5%), nonalcoholic steatohepatitis-NASH (n=10,6.8%). Most common consult diagnoses were vascular disease (n=22,15%), primary biliary cholangitis-PBC (n=19,12.9%), NASH (n=13,8.8%), AIH (n=12,8.2%) (p<0.001). Major change in initial diagnosis was noted in 73(49.6%), minor changes in 37(25.2%) and no change in 23(15.6%). For tumours (n=72,32.9%), most common initial diagno- ses were hepatocellular carcinoma-HCC (n=23,31.9%), nonspecific (n=14,19.4%) or metastatic (n=6,8.3%). Most common consult diag- noses were HCC (n=36,5%), cholangiocarcinoma-CCC (n=5,6.9%) or non-tumour parenchyma (n=4,5.6%) (p=0.033). Major change in initial diagnosis was noted in 30(41.7%), minor changes in 24(33.3%) and no change in 15(20.8%). Conclusion: Study of liver consult patterns provides useful informa- tion on areas of hepatopathology posing diagnostic difficulty. The majority of consult cases in our centre are submitted by hepatologists. The most common diagnostic challenges in medical cases are vascular liver disease, interpretation of hepatitic pattern of injury, and recogni- tion of primary cholangiopathy, while in tumour cases these include classification and subtyping of hepatocellular tumours. These areas can be the subject for future continuing medical educational activities in hepatopathology. E-PS-07-022 Reflux-associated cholecystopathy with pancreaticobiliary maljunction: a case report G. Güngör Sahin*, M. Buyuk, N. Berker, B. Acunas, M. Gulluoglu *Istanbul University, Istanbul School of Medicine, Department of Pathology, Turkey Background & objectives: Pancreaticobiliary maljunction (PBM) is defined as congenital fusion of common bile duct and pancreatic duct outside the wall of duodenum and it leads to reflux-associated chol- ecystopathy. It occurs more often in Asian populations and may cause carcinomas of pancreaticobiliary system. Methods: A 57 year-old woman presented with right upper quadrant abdominal pain. After clinical and radiologic examinations, she under- went cholecystectomy for gallbladder polyps. Results: The cholecystectomy material was measured 8,5x4,7x0,4 cm. The mucosa was 0,3 cm thick and yellow coloured. No localised polypoid lesion or stone were observed. Microscopically; diffuse mucosal hyper- plasia with villoglandular appearance and amyloid-like substance accu- mulation at the tips of papillae were detected. Intestinal metaplasia was focally observed and no inflammation was detected. These findings were consistent with reflux-associated mucosal damage resulting from PBM. Magnetic resonance cholangiopancreatography scan showed that the junc- tion between common bile and pancreatic ducts was located 1 cm proximal to the sphincter of Oddi outside the duodenal wall, and the main hepatic and common bile ducts were dilated (12 mm and 8 mm, respectively). Conclusion: Understanding the histopathologic characteristics of reflux-associated cholecystopathy is important as it is associated with PBM which increases the risk of neoplastic development in pancreati- cobiliary tract. It is recommended to identify patients with this anomaly for prophylactic cholecystectomy and radiologic follow-up for any neo- plastic development. E-PS-07-023 A case report: concomitant lymphoplasmacytic sclerosing pancrea- titis and lymphoplasmacytic sclerosing cholangitis I. Guzelis*, A. Akder Sari, O. Gunes *Izmir Katip Celebi University, Ataturk Training and Research Hospi- tal, Department of Pathology, Turkey Background & objectives: IgG4-related sclerosing diseases can affect any organ and clinically can mimic malignant tumours. In the pan- creas, it is variously termed lymphoplasmacytic sclerosing pancreatitis (LPSP) or autoimmune pancreatitis. LPSP usually responds to corti- costeroids, making it important to differentiate from pancreatic ductal adenocarcinoma. Methods: A 53-year-old woman presented with jaundice. Biochemical analysis revealed elevated AST, ALT, ALP, GGT, and bilirubinemia. On abdominal ultrasound, intrahepatic bile ducts were diffusely dilated, and a pancreatic head mass was detected. PET CT and MRCP disclosed two malignant suspicious masses which were located in the pancreatic head and main bile duct bifurcation. Results: The patient underwent a Whipple procedure with the excision of extrahepatic bile ducts. The gross examination showed a 3 cm ill-defined mass in the pancreatic head and thickened segments of extrahepatic bile ducts. Microscopically, both lesions revealed dense lymphoplasmacytic inflammation particularly centred around neurons and ducts. Oblitera- tive phlebitis along with periarteritis and periartheriolitis were observed. Acinar atrophy and prominent storiform-type fibrosis were present. IgG- positive plasma cells were higher than 50/HPF and IgG4/IgG percent- age was 60% (>40%). The case was diagnosed as lymphoplasmacytic sclerosing pancreatitis (autoimmune pancreatitis type 1, IgG4-related pancreatitis) and lymphoplasmacytic sclerosing cholangitis. Conclusion: Lymphoplasmacytic sclerosing pancreatitis or cholangitis might mimic carcinomas both clinically and radiologically. If untreated this disease can lead to pancreatic insufficiency, fibrosis, and other complications. Given that there is a dramatic response to corticosteroid treatment, it is important to beware of this entity. E-PS-07-024 Immunohistochemistry in adenocarcinoma liver metastasis M. Heritier*, T. Fenouil *Hospices Civils de Lyon, France Background & objectives: Adenocarcinoma liver metastasis (ALM) origin is essentially diagnosed with the expression of immunomark- ers. However, we mostly know the expression pattern of these markers in primitive tumour rather than ALM. Hence, we aim to describe the expression of those in ALM. Methods: A retrospective cohort of 231 ALM patients split into 7 origin groups were included in this study. Two pathologists, blind- folded with the origin site, went throught a semi-quantitative analysis of 18 immunomarkers (including several keratines, and “tissu-specific” markers) on each case. A preliminary statistical analysis was made, which will further be completed by clustering analysis, k-means, and combinatorial analysis. Results: Keratines were globally well expressed in ALM from every origins, excepted for CK20, which was restrained to specific origin groups. As for tissu-specific markers, unexpected but significant expressions were found: there was a low frequency of GATA3 expres- sion in every studied origin group, and chromogranine A in almost every group. TTF1 was expressed in some colorectal tumours (4/49). p40 was observed in certain groups (extrahepatic cholangiocarcinoma, pancreas, lung, breast and oesophago-gastric) without any previous description of it. PDX1 was weakly expressed in every group except from breast. There was a weak expression of PAX8 in some breast metastasis.