ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 findings support the hypothesis that GCT is associated with reac- tive changes of the neural/schwannian cells, rather than a true neo- plasm. This case documents a granulomatous appendicitis (which is a rare entity, <2% of appendectomies) and a GCT as a cause of appendicitis. E-PS-06-013 Clinicopathological and histomorphological association in K-ras mutated colorectal cancer D. Jasar*, V. Filipovski, K. Kubelka - Sabit *Department of Histopathology and Cytology, Clinical Hospital Acibadem/Sistina, Skopje, Faculty of Medical Sciences, University “Goce Delchev” – Shtip., North Macedonia Background & objectives: KRAS mutation is frequently identified in advanced colorectal carcinoma (CRC)and its prognostic significance with histological features have remained to be clarified. The aim of this study is to evaluate the clinicopathological and histomorphological characteristics in K-ras mutated patients with CRC. Methods: In this retrospective study, 420 CRC patients who under- went surgical treatment in our hospital (January 2018- December 20200 have been included. K-ras mutation testing was performed in 265 patients, detected by Cobas K-ras mutation kit to identify frequent mutations (codons 12,13,61). Clinicopathological and histomorphological data were compared with the K-ras status and correlations were evaluating using Pearson’s Chi-square test. Results: K-ras mutations were found in 148 patients (39,2%), fre- quently identified in older males, and in advanced stages of the dis- ease. There was association of the K-ras mutation with the degree of tumour differentiation (G3), tumour necrosis and inflammatory response of the tumour tissue (p<0.05). No association was found between the mutational status and the tumour extention, localiza- tion, lymphonodal status and tumour type. Conclusion: According to the certain limitations of this retro- spective study using a single detection kit that include common codon changes in K-ras gene it is obvious that further studies on the histological results and their prognostic value of rare KRAS codon variants are necessary. From the other perspective, the pre- sent study demonstrated a moderate association between KRAS- mutated CRCs and specific histology, and, to a certain degree, an association between histology and prognosis, according to KRAS mutation status. E-PS-06-014 The role of IL-23 positive cendritic cells in development of gas- tric cancer J. Ananiev*, K. Ivanova, M. Hadzhi, E. Aleksandrova, M. Galabova *Medical Faculty, Trakia University, Bulgaria Background & objectives: Many molecular and cellular factors play an important role for development of gastric cancer prognosis and pro- gression. The aim of our study was to investigate infiltration with IL-23 positive dendritic cells (DCs) and clinicomorphological parameters in the progression of GC. Methods: We investigated 40 patients, having GC immunohis- tochemically with antibodies against IL-23, CD83 and S100. The clinicopathological parameters and survival were analysed retrospectively. Results: The infiltration with IL-23+DCs in tumour stroma was 26.92+/-7.5 cells/mm2, and in tumour border - 59.3+/-11.8 cells/ mm2 (p=0.024, Wilcoxon Signed rank test). 87.1% of the patients with low infiltration were in T3 and T4 tumour stage vs. close to 50% from group of patients with high infiltration were in the same stage (р=0.003). In addition, 65% from low differentiated tumours were with low infiltration with DCs, vs. low infiltrated with DCs moderate and high differentiated tumours (р<0.001). Conclusion: Our results suggest that IL-23 positive dendritic cells play role in tumour progression and could be useful as a prognostic marker of in gastric cancer patients. Funding: This work financially supported by the National Sci- ence Fund, Bulgaria, Research grant number КП-06-Н23/2 from 17.12.2018 E-PS-06-015 A study of HLA-G expression profiling in colorectal cancer N. Boujelbene, I. Zemni, S. Dhouioui*, H. Ben Yahia, W. Babay, M. Ferjani, K. Mrad, H. Ouzari, I. Zidi *Laboratory Microorganismes and Active Biomolecules, Sciences Faculty of Tunis, Tunisia Background & objectives: Human leucocyte antigen(HLA)-G is a powerful molecule involved in immune tolerance. Previous studies have proposed HLA-G as a potentially good candidate for immune- checkpoint target immunotherapy. We aimed to assess the expression of HLA-G in colorectal cancer(CRC) according to clinicopathological characteristics. Methods: Immunohistochemical analysis was performed on a total of 22 patients with CRC and their adjacent normal tissues using the 4H84 anti-HLA-G monoclonal antibody. Staining intensity was assessed. Expression levels were classified semi-quantitatively based on immunoreactive cells percentage. Clinico-pathological characteristics were recorded. Results: Patients age range was of 31 to 93 years (mean = 63 years). HLA-G was significantly expressed in all CRC tissues (100%) and under-represented in normal tissues (10%) (Mann Whitney U test: p< 0.0001). The scores of expression of HLA-G in tumour tissues were highly intensive compared to normal tissues (p<0.0001). Interestingly, high HLA-G expression was reported in early stages (I+II) compared to advanced stages (IV+V) without significance (p=0.635). Conclusion: Altogether, our results showed that HLA-G could be proposed as a candidate biomarker that can be useful for the evaluation of patients’ prognosis and a potential target for CRC therapy. E-PS-06-016 Fibrosis of the muscular layer of the colon as a predictor of the complicated course of diverticulosis L. Mikhaleva*, A. Konyukova, N. Gutyirchik *A.P. Avtsyn Research Institute of Human Morphology, Russia Background & objectives: Colonic diverticulosis is an actual prob- lem of modern healthcare with complicated diverticulosis being a life threatening condition. The aim of our study is to determine the mor- phological predictors of the complicated diverticulosis. Methods: We analysed 79 consecutive cases of left-sided hemi- colectomy, 15 cases were studied comprehensively. Surgical speci- mens were fixed in 10% neutral buffered formaline and stained with haematoxylin and eosin and Mallory. Morphometric evaluation was performed in order to assess the area of fibrosis in the muscular layer of the colon outside the diverticula in 20 fields of view at x200 magnification. Results: Among 15 extensively studied cases 6 patients (40.0%) had complicated diverticulosis of the colon, 5 (33.0%) presented S220