ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 N. Zhelezniakova, V. Gargin*, T. Bocharova, T. Pasiieshvili, L. Pasiyeshvili, V. Sakal *Kharkiv National Medical University, Ukraine Background & objectives: Gastroesophageal reflux disease (GERD) takes one of the leading positions in internal organs` pathology with comorbidity. Objective of our work was evaluation of morphometric parameters of the esophageal mucous membrane in young people with GERD and autoimmune thyroiditis (AIT). Methods: Patients with GERD and AIT (main group) and 45 peo- ple with isolated GERD (comparison group) matched for age, gen- der, and social status were examined. The mean age in the groups was 21.9 ± 2.7 and 21.2 ± 2.4 years. Morphometric parameters were obtained (total thickness of the epithelium, basal layer thick- ness, the height of connective tissue papillae, and intercellular space). Results: The histological study showed that in patients with GERD and AIT all the morphometric parameters studied had a signifi- cantly more severe course and exceeded similar indicators of the group with isolated GERD: epithelium total thickness 319.3±9.1 μm against 286.1±8.2 μm (p<0.01), epithelium basal layer thick- ness 79.6±3.2 μm versus 49.7±2.1 μm (p<0.01), connective tis- sue papillae height 224.8±7.3 μm against 172.7±4.6 μm (p<0.01), intercellular space 1.55±0.11 μm versus 1.12±0.09 μm (p<0.01). Considerable aggravation of the deviations in patients with AIT may reflect the involvement of an additional autoimmune inflam- matory component in the pathological process. Conclusion: GERD and euthyroid AIT comorbidity in the stu- dent population is accompanied by statistically more pronounced disorganization of esophageal mucosal epithelium compared with isolated GERD. The obtained data allow us to consider concomi- tant AIT as an unfavorable prognostic factor in the progression of GERD in the student population. E-PS-06-054 Did the COVID-19 pandemic impact the presentation and man- agement of colorectal cancer in a Tunisian population? G. Sahraoui*, N. Kouki, K. Tlili, R. Doghri, L. Charfi, I. Ben Safta, K. Mrad *Pathology Department, Salah Azaiez Institute, Research Labora- tory LR21SP01, Tunis, Tunisia Background & objectives: The implemented measures during the COVID-19 pandemic disrupted health care access, especially in low income countries. We aimed to determine the impact of the COVID-19 pandemic on management and presentation of colorectal cancer (CRC) in a Tunisian population. Methods: We selected two groups of patients with newly diag- nosed and treated CRC in Salah Azaiez institute, in the pandemic era (1 March 2020-1 December 2021) and in a corresponding time interval of the prepandemic era (1 March 2020-1 May 2018). Clinicopathological data were retrieved from pathologi- cal reports and compared between the two groups. Results: The number of newly diagnosed CRCs was lower in the pandemic era (49 cases versus 82 cases). These patients presented at a significantly (p<0.01) younger age andwith a greater tumour size (median age of 58 versus 62 and tumour size of 40 mm versus 30 mm). Among patients prescribed neoadjuvant treatment, 78% accessed it in the pandemic interval versus 70% in the second group. Lymph node involvement was significantly higher in patients of the prepandemic interval (51% versus 30%, p=0.02). There was no difference in T stage presentation (p=0.2), lymphovascular invasion rates (p=0.3) and tumour regression rates (p=0.1) between the two cohortes. Conclusion: Although the demographic characteristics of patients with CRC diagnosed in the pandemic era were worse, there was no difference in histopronostic factors and health care access. With limited resources, tunisian health care system seemed to resist COVID-19’s pandemic impacts. E-PS-06-055 Tumour budding: a strong and reproductible prognostic marker in stage II colorectal carcinoma A. Baccouche*, N. Abdessayed, W. Majdoub, T. Zahmoul, H. Hamchi, O. Belkacem, M. Mokni, S. Hmissa *Pathology Department, Sahloul University Hospital of Sousse, Tunisia Background & objectives: StageII colorectal carcinoma is a heterogene- ous group with a 5-year survival ranging from 32,3% to 66,5%. Recently, tumour budding (TB) has been recognized as a strong prognostic factor to select a subset of patients who may benefit from adjuvant therapy Methods: 172 stage II colorectal carcinoma (CRC) patients with known outcome have been identified between 2007 and 2014. TB was defined as single tumour cells or clusters of <5 cells at the invasive tumour front. It was assessed by two different patholo- gists using the hot spot method. A score using a 3-tier system and a grade were finally attributed. Results: 47 (27,4%) carcinomas had high and 125 (72,6%) had low budding scores. High grade budding was associated with an infiltrative growth pattern (p<0,001), lymphovascular invasion (p=0,011), neural invasion (0,002) and intratumoural lymphocyte infiltrate (p=0,003). Five-year cancer-specific survival was significantly poorer in high com- pared with low budding groups: 68% versus 80% (P=0.023). Multi- variate analysis demonstrated tumour budding to be an independent prognostic factor (hazard ratio=2,33, P=0.012). Interobserver agree- ment was moderate for both score and grade: 74,4% agreement (k=0.4) versus 66,9% agreement (k=0.23), respectively. Conclusion: In view of these findings, the use of TB as a repro- ductible and independent prognostic marker, easily assessed on hematoxylin and eosin slides, to identify a subset stage II CRC patients at high risk of recurrence and who may benefit from adju- vant therapy, had been advocated. E-PS-06-056 A retrospective study investigating how common serrated adenocarcinomas are and whether it is possible to identify from morphology and immunohistochemistry A. Arnaout*, A. Andrade *St Georges Hospital London, United Kingdom Background & objectives: Sessile serrated adenocarcinoma is a chal- lenging subtype that is rarely used in pathology reports. In previous studies the CK7+/CK20+ pattern of expression is displayed in ser- rated adenocarcinomas. In this project we tested such an expression retrospectively. Methods: Haematoxylin and eosin (H&E) analysis on 100 cases of primary CRC samples identified serrated morphology on 37% of cases. Immunohistochemistry (IHC) staining using CK7 (clone: SP52; pre-diluted; ROCHE Diagnostics, Switzerland) and CK20 (clone: SP33; pre-diluted; ROCHE Diagnostics, Switzerland) antibodies was carried out via Ventana automatic Immunostainer (BenchMark Ultra IHC/ ISH System). Results: CK7+/CK20+ pattern of expression was present in 21% of cases. 11% of CRC cases studied displayed general CK7+/ CK20+ expression, as well as that same pattern in both serra- tion and tumour components specifically. This evidence supports Hirano, et al., 2019 findings in which it is considered that the S231