ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 with uncomplicated diverticulosis and 4 (27.0%) had no diverticula of the colon (comparison group). The area of fibrosis in muscu- lar layer of colon progressively enhanced from comparison group to complicated diverticulosis group. In cases with complicated colonic diverticulosis fibrosis of the muscular membrane was 106.5 times more prominent (21.3%) and in cases with uncomplicated diverticulosis - 39 times more extensive (7.8%), both compared with comparison group (0.2%). Conclusion: The present study demonstrates that the area of fibro- sis of the muscular membrane is significantly more extensive in patients with complicated colonic diverticulosis (106.5 times) and in patients with uncomplicated course of diverticulosis (39 times) compares with the comparison group. Our results indicate that the presence of fibrosis in the muscular membrane of the colon should be considered as a predictor of the development of diverticulosis, and its severity being a predisposing factor for complicated course of the disease. E-PS-06-017 An unusual histopathological morphology of collagenous gastritis Z.J.O. Lee*, J. Lum *Department of Pathology, National University Hospital, Singapore Background & objectives: Collagenous gastritis is an extremely rare and poorly understood disease defined by subepithelial collagen deposi- tion and inflammatory infiltrate in the lamina propria. Methods: We present the case of a 27-year-old women with dyspepsia for 2 to 3 years with no other red flag symptoms and distinctive findings in her physical examination. Extensive blood workup including autoimmune disease screening panel, computed tomography and upper endoscopy were performed. Results: The blood workup revealed features of iron deficiency anaemia. Computed tomography scan demonstrated stomach antral wall thickening with no other significant findings within the rest of the intestinal tract. An upper endoscopy showed diffuse nodular thickening in stomach antrum and corpus with severe atrophy. His- topathological examination of the stomach biopsy specimen showed atrophic gastritis with extensive collagen deposition within the sub- epithelial region and extending throughout the lamina propria into the submucosa, confirmed by masson-trichrome stain. No amyloid deposition or features of IGG4 related disease demonstrated. A diagnosis of collagenous gastritis was made after excluding dif- ferential diagnoses such as systemic sclerosis and IgG4-related disease. Conclusion: We present an unusual case of collagenous gastritis with diffuse collagen deposition within the full thickness of the mucosa. Although such extensive collagen deposition secondary to autoimmune and IgG4-related conditions must be considered, our case has shown that collagenous gastritis cannot be excluded. We hope it’s unusual finding will benefit other diagnosing clinicians having similar problems. E-PS-06-018 Prognostic significance of cyclin D1 over-expression in colo- rectal cancer A. Dhaoui*, D. Aloui, M. Safer, S. Ben Rejeb, M. Aloui, R. Bahl- oul, T. Jomni *Forces de securité interieure, Tunisia Background & objectives: CyclinD1 is a key regulatory protein and is over-expressed in many cancers.The main aim of the study is to examine the expression pattern of cyclin D1 and its correlation with the different clinicopathological features in colorectal cancer (CRC). Methods: The archival tumour blocks were analysed using immunohistochemistry for CyclinD1 over-expression in 32 CRC patients diagnosed from 2013 to 2019 at the Pathology Department Interior security hospital,Tunisia.The nuclear staining of cyclin D1 was reported in score to define Low and High score.Fisher’s exact tests was performed to extract the significant level of association between cyclinD1 over-expression and the clinicopathological parameters. Results: Mean age of patients was 64,5 with a sex ratio of 2,2. The commonest histological type was adenocarcinoma, seen in 30 cases (94%), and the majority of the tumours were moderately differentiated. Approximately 62.5% of cases had positive lymph node. Distant metastases were seen in 46% of cases.Cyclin D1 over-expression was absent in normal mucosa. In CRC, Cyclin D1 was expressed at high levels in 46% of case. No significant correlation was observed between Cyclin D1 over-expression and age, gender, tumour size, location, type, tumour differentiation, lymph node involvement and lymphovascular invasion. However, Cyclin D1 over-expression exhibited a significant correlation with, distant metastasis (p=0.034) and AJCC staging (p=0.034). Conclusion: The role of cyclin D1 over-expression in CRC is somewhat controversial.While some reports have observed a significant association between its expression and poor survival outcomes, others have reported it as a marker of a good prognosis. In our study, Cyclin D1 over-expression increases during normal-adenoma-carcinoma sequence. The significant association observed between Cyclin D1 over-expression, distant metastasis and advanced tumour stage clearly suggest the role of Cyclin D1 in the carcinogenesis and progression of CRC. E-PS-06-019 Mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) of the Vater Ampulla in a Portuguese patient: a case report C. Courelas*, R. Oliveira, J. Gama, J. Madeira, A. Alves, M.A. Cipriano *Centro Hospitalar e Universitário, Portugal Background & objectives: Mixed neuroendocrine-non- neuroendocrine neoplasms (MiNENs) are defined by WHO as mixed neoplasms with neuroendocrine and non-neuroendocrine components. Described in various organs, these neoplasms are commonly found in the Pancreas and Gastrointestinal tract, being rare in the Vater ampulla. Methods: We describe a case of a 74-year-old woman, referred to our hospital’s oncologic reference centre for hepatobiliary and pancreatic cancer. Patient initially presented with new-onset Diabetes and was diagnosed with a tumour of the Ampulla, without radiological evidence of metastatic disease. Cytology examination from fine needle aspiration suggested carcinoma. Results: A pancreatoduodenectomy was performed. On gross examination there was a lesion confined to the Ampulla with 2.4 cm, composed of a white and friable tissue. Histopathologic exami- nation revealed an ampullary mixed neoplasm with a large cell neuroendocrine carcinoma and a non-neuroendocrine component: moderately differentiated adenocarcinoma, with pancreatobiliary phenotype without microsatellite instability. Tumour was limited to Ampulla and lymph nodes were free from metastatic disease – pTMN: T1a N0. Conclusion: MiNENs of the Ampulla of Vater are described only in scarce case reports. MiNEN are highly aggressive and with high S221