ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Results: 9 cases were evaluable. They were 3male and 6 female patients, ages ranging from 5 to 75 years with an average of 29,5 years. Among these cases, 2 involved the brainstem and 7 involved the parietal lobe. All of patients had a rural origin and contact with dogs. The clinical presentation was dominated by intracra- nial pressure syndrome with focal neurologic deficit. The radio- logic findings range from purely cystic lesions to a completely solid appearance. All of the patients underwent surgical treatment. The histological examination had adjusted the diagnosis showing hydatid membranes with an eosinophilic laminated appearance, containing daughter cysts filled with gel-like fluid and a pericyst on the periphery. Conclusion: While the liver is usually the most frequently involved organ in hydatid disease, the nervous central system (NCS) is still a rare location leading to several complications in case of late diag- nosis. The main diagnostic tool remains always the histopathologic examination PS-24 | Poster Session Other Topics PS-24-001 Group work in the annotation of virtual pathological slides D. Jovanovic* *Trinity Medical Sciences University, USA Background & objectives: One of the important goal of modern medi- cal education is to create a learning environment for interactive dis- cussion and collaboration. The objective of our study was to compare the results of individual and team annotation of digitized pathological slides. Methods: Based on students’ academic performance, gender and ethnicity, heterogeneous teams were created randomly. Students first annotated virtual slides individually and then in a group. Dif- ferences in individual and group scores were tested using paired samples T-test. Probability level of p < 0.05 was considered sig- nificant. Normality of distribution of students’ answers was tested using the Kolmogorov-Smirnov test. Results: General pathology students scored significantly higher (p<0.001) in group (Average group score 25.0, SD 2.4) as opposed to individual readings (Average individual score 3.6, SD 1.6). In T4 group studying systemic pathology and working in a group scored significantly higher (Average group score 60.8, SD 6.0, p<0.00) compared with individual annotations (Average group score 26.5, SD 11.0). A similar finding was observed when the scores were stratified according to students groups, all groups in Term 3 and in Term 4 achievement was significantly higher (p<0.003) in group compared with individual reading. Both the students with lower and with higher academic achievement significantly (p<0.03 and p<0.05, respectively) improves the results. Conclusion: Group work in the annotation of pathological slides has learning potential and facilitate interaction between students. This way of analysing pathological slides significantly improves the results of students with lower as well as of students with higher academic achievement. Team work is a part of active learning and is the most important task of modern and high-quality healthcare education. This is supporting students to become reflective and competent physicians. PS-24-002 Level of IgG to glu-plasminogen in blood plasma as marker of breast cancer P. Vishnyakova*, E. Goufman, N. Tikhonova, A. Alexankin, M. Boltovskaya, N. Nizyaeva, L. Mikhaleva *National Medical Research Center for Obstetrics, Gynaecology and Perinatology named after Academician V.I. Kulakov, Russia Background & objectives: Plasminogen plays an active role in tumour metastasis as a proteolytic enzyme. The study aimed to analysed poten- tial diagnostic power of circulating IgG to Plasminogen in blood of mice with and without breast cancer Methods: Plasma samples were obtained from Balb/c mice with (n = 25) and without (n = 20) breast cancer. The level of IgG binding plasminogen was analysed by ELISA on 96-well plates with immo- bilized glu-plasminogen. The comparisons of mean OD between cohorts were performed by the Mann–Whitney U-test. Potential diagnostic power of IgG was investigated by ROC curve analysis Results: Breast cancer in mice was confirmed using physical exami- nation and biopsies. Plasma samples from breast cancer and healthy mice were incubated in 96-well plates coated with glu-plasminogen and IgG binding was measured by HRP-conjugated anti-mouse IgG Abs. We observed significantly higher circulating levels of IgG to plasminogen in a group of mice with breast cancer compared to a group of healthy mice (p<0.05). In ROC curve analysis the sensitiv- ity of the classification of breast cancer from healthy controls was 72%, the specificity was 95% and the area under the curve was 0.93 Conclusion: Our results require further confirmation in women with breast cancer and investigation of the mechanism of IgG bind- ing to glu-plasminogen in blood. The potential diagnostic power of circulating IgG to glu-plasminogen in blood of patients with breast cancer and healthy woman could be a promising candidate biomarker for the early diagnosis of breast cancer. Funding: The study was carried out within the framework of state assignment to A.P. Avtsyn Research Institute of Human Morphol- ogy (No. 122030200534-4) PS-24-003 Formalin-fixed, paraffin-embedded (FFPE) block stability using PD-L1 IHC 22C3 pharmDx C. Roach* *Agilent Technologies, USA Background & objectives: PD-L1 IHC 22C3 pharmDx is a qualita- tive immunohistochemical (IHC) assay for PD-L1 expression in FFPE specimens routinely processed for diagnostic evaluation. A stability study was performed to assess the effects of PD-L1 expression in aged FFPE blocks stored over time. Methods: Human placenta tissue was used as a model since syncy- tiotrophoblastic cells have features similar to malignant cells. Fresh tissue was procured and prepared as FFPE blocks to control pre- analytical variables such as processing, ischemic time, and fixation time. Fifteen placenta blocks from 5 cases were stained by IHC at intervals from 0-60 months (5 years) using PD-L1 IHC 22C3. Results: PD-L1 expression was evaluated and assessed for any changes in overall staining intensity over time compared to the initial Time 0 staining. Our results showed no significant change in PD-L1 expression in sections from aged FFPE placenta tissue blocks stored in the dark with ambient conditions over time for up to 5 years. Similar sensitivity to titrations was observed between placenta and NSCLC. Conclusion: FFPE tissue blocks stored in the dark at ambient tem- perature for up to 5 years demonstrated similar PD-L1 expression compared to non-aged blocks and thus, demonstrate stability over time. Funding: Merck & Co., Inc S164