ECP 2023 Abstracts

S217 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 of oncological resection, residual disease and LNM were recorded, and corresponding risk factors evaluated. Results: We identified 30 screening and 25 non-screening T1 CRCs in polypectomy specimens with a mean age of 65.6±2.7 years and 70.1±10.7 respectively. At least one high-risk feature was present in 80% of cases, including high tumour grade (16.4%), tumour budding (36.4%), incomplete resection (49%), lymphatic (47.3%) and venous invasion (25.4%). Twenty-six patients (47%) underwent oncological resection with screening cases more likely to be referred (53%vs40%). Residual disease was less common in screening cases (10% vs 24%), while LNM were more common (6.7% vs 0%). Tumour deposits (TDs) rates in fat were similar (6.7%vs8%). Recurrence rates were 3.6% (all were non-screening cases) with a median follow-up of 35 months (range 2-116). Conclusion: We report low rates of LNM (3.6%), residual (16.4%) and recurrent (3.6%) disease following oncological resection in T1 CRCs. Little data is available regarding TDs, an under-recognised poor prognostic factor which we identified in an appreciable number of cases (7.3%). Screening cases were more likely to undergo surgery, possibly due to younger age as high-risk feature rates were similar. Differences in patterns of residual disease and LNM were identified in screening cases. E-PS-06-094 Metastatic melanoma to the gallbladder- a case report L. Williams*, A. Arnaout *St George’s Hospital, London, United Kingdom Background & objectives: Melanoma metastasises most frequently to the skin, lung and liver, and literature reports that <5% metastasise to the gastrointestinal tract. When this occurs, the most common sites are the small bowel, colon and stomach. The gallbladder is an uncom- mon site. Methods: A 75 year old lady with a 2 year history of sinonasal mel- anoma presented to our teaching hospital with a gallbladder lesion. Cholecystectomy was performed, revealing a 35x18x15mm lesion at the fundus and a separate 17x15x3mm lesion just proximal to the first. Both had a brown/grey cut surface and fleshy appearance. Results: Histology revealed a malignant melanoma, characterised by sheets of atypical cells with moderate nuclear pleomorphism, promi- nent nucleoli and frequent mitoses. The tumour displayed areas of infarction, necrosis, and cells showed strong nuclear expression of SOX-10, with cytoplasmic Melan-A and HMB45. S100 was focal. Cystic duct node was negative for metastasis. Conclusion: Here we report a case of sinonasal melanoma with an unu- sual location for metastasis. In this instance, two adjacent lesions were present. Metastatic melanoma to the gallbladder is an unusual event with poor prognosis, and controversy remains over optimal treatment. Given that these lesions are often found incidentally with few symp- toms, detection is often late, and treatment of gallbladder metastasis remains a clinical difficulty. E-PS-06-095 Enterogenous cyst causing intussusception in an adult- a case report L. Williams*, A. Arnaout *St George’s Hospital, London, United Kingdom Background & objectives: A 43 year old female presented to our university hospital with intussusception at the ileo-caecal valve. Emer- gency surgery revealed small bowel containing a cystic lesion, which was excised and sent for histology. Methods: A 40x40x35mm small bowel specimen was received, and opening revealed a unilocular structure, comprising flattened cyst wall within the small bowel lumen. The mucosa appeared focally haem- orrhagic and congested and the lesion was photographed clinically. Histology revealed a cystic structure lined by cuboidal and columnar epithelium, with smooth muscle fibres within the walls. No atypia or malignancy was present. Results: Intussusception in an adult accounts for around 1% of bowel obstructions, with enterogenous cysts being an unusual cause for this. Most enterogenous cysts remain asymptomatic until secondary events, such as obstruction, bleeding or perforation occur. They remain an important cause to consider in such situations. The origin of these cysts remains controversial, with the most accepted explanation being that of duplication of the gut occurring due to ’pinching off of a diverticulum’ during embryological development. Once detected on imaging, resec- tion of the cyst may be indicated, however radiological surveillance may also be considered in some instances. Conclusion: Enterogenous cysts are a rare congenital entity, which, when found in the small bowel, often involve the ileum. Most often seen in children, there are very few case reports of this presentation in adults. E-PS-06-096 Granulomatous gastritis in a patient with sarcoidosis B. Yeni Erdem*, G. Kat Anıl *Kartal City Hospital, Department of Pathology, Turkey Background & objectives: Granulomatous gastritis is a specific pat- tern of gastritis, characterized by the presence of granulomas in gastric mucosa. In most cases, the cause cannot be determined without clinical information. Infections, inflammatory diseases such as sarcoidosis and Crohn’s disease should be investigated. Methods: We present a 74-year-old female patient who presented with complaints of chronic dyspepsia. Upon examination, she was found to be anaemic. Upper endoscopy revealed that the gastric fundus and corpus mucous membranes were pale, while the antrum was hyperae- mic and oedematous. Multiple biopsies were taken with a preliminary diagnosis of atrophic gastritis. Results: Biopsies from the antrum revealed chronic active gastritis. Biopsies from the corpus also revealed chronic active gastritis with well-formed, non-necrotizing granulomas. Granulomas had histiocytic giant cells in the centre and no caseification. Helicobacter pylori were present on the surface. No other microorganisms were identified on histochemical stains. We signed out the case as granulomatous gastritis. Subsequently, it was discovered that the patient was diagnosed with sarcoidosis, but she was unwilling to get a treatment and she refused to be followed up. She had been suffering from a chronic cough for an extended period. Conclusion: It is controversial if Helicobacter Pylori can cause granuloma. They are thought to be coincidental and its presence in granulomatous gastritis is not uncommon. It is therefore crucial to investigate other potential causes of gastric granulomas as they may be a significant indicator of underlying primary diseases that are yet to be detected. E-PS-07 | E-Posters Digestive Diseases Pathology - Liver/Pancreas E-PS-07-002 The decreasing expression of albumin mRNA in cholangiocarcino- mas along the biliary tree: implications for differential diagnosis in liver lesions E. Albertini*, S. Chillotti, D. Malvi, M. Deserti, A. Degiovanni, A. Palloni, S. Tavolari, G. Brandi, A. D’Errico, F. Vasuri