ECP 2023 Abstracts

S136 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 Conversely, 1/24 SVs and 5/11 CNAs were missed by TSO. Average positive agreement for CNAs was 28.5%; average negative agreement was 98.0%. Tumour mutational burden (TMB) with TSO was significantly higher vs AVENIO (regression modelling, p<0.001); TSO called n=41/145 samples TMB-high, vs 31/145 samples for AVENIO. Recent guidance suggests TMB algorithms should account for germline and somatic driver mutations. Differences in bioinformatic approaches raise con- cerns about TMB overestimation by TSO. Conclusion: With advances in molecular guided therapy options, CGP solutions should robustly detect guideline-relevant alterations. Two commercially available CGP solutions with tertiary analysis software had differences in the detection of TMB and ESCAT bio- markers, including CNAs. These differences can be largely explained by differences in variant calling and filtering algorithms and are important considerations for any diagnostic CGP offering, raising concern of inaccurate results if not properly controlled. Funding: F. Hoffmann-La Roche Ltd/Roche Diagnostics International Ltd. PS-25 | Poster Session Pathology in Favour of Developing Countries PS-25-001 Evaluation of 70% isopropyl alcohol as a fixative medium in surgi- cal cooperation campaigns: a pilot study M. Bronte Anaut*, J. Arredondo Montero, E. Carracedo Vega, A. Moreno Ibérico, Y.P. Rodriguez Velandia, Y. Ruiz de Azua-Ciria, C. Bardají Pascual, R. Guarch Troyas *Hospital Universitario Araba, Spain Background & objectives: The lack of adequate resources in interna- tional cooperation limits the study of anatomopathological specimens. The literature on potential inexpensive and available fixation media is scarce. Methods: Lesions were prospectively collected during a surgical coop- eration campaign in 2022. Lesions were fixed in parallel in 5% formalin (FF) and 70% isopropyl alcohol (AF). H&E sections and immunohisto- chemistry (IHC) techniques were performed. Images were anonymized and assessed by 2 senior and 2 junior pathologists, evaluating the qual- ity of staining and diagnostic feasibility by means of an anonymized questionnaire. Results: Three surgical specimens were included: 1 lymph node (3 H&E, 4 HIC), 1 seborrheic keratosis (2 H&E, 5 HIC), 1 branchial remnant (2 H&E, 2 HIC). Fixation times were similar in all the specimens (10-13 days). All FF H&E were diagnostic. AF H&E was 100% diagnostic in 5/7 sections and 75% diagnostic in the two remaining sections. In most cases pathologists preferred FF. CK7 (x2), P40, EMA, CKAE1AE3 and TTF1 were 100% diagnostic in both groups. CD20, CD45 and EMA were 100% diagnostic (FF) and 75% diagnostic (AF). CD10 was 75% diagnostic (FF) and 25% diagnostic (AF). BCL6 was 75% diagnostic (FF) and 100% diagnostic (AF). IHC preferences were inconsistent. Conclusion: 70% Isopropyl alcohol has a worse fixation profile than 5% formalin but allows diagnosis in most cases. The immunoreactivity observed is variable depending on the tissue and the stain used. Based on these findings, it can be considered an inexpensive, readily avail- able and potential useful fixation medium for diagnosis in developing countries where surgical cooperation campaigns are developed. Future studies of larger sample size and characterizing other histologic sub- types are needed to confirm these findings. PS-25-002 Opting surgical pathology as a future specialty; student’s perspec- tive from Lahore, Pakistan F. Rehman*, F.N. Alam, M.U. Farooq, R. Saqib, S. Hameed, A. Hamid *Associate professor Pathology department, Ameerudin medical col- lege/postgraduate medical institute, Lahore, Pakistan Background & objectives: Choosing a medical specialty is crucial to a medical student’s long-term career goals. The aim of this study is to eval- uate inclination of medical students towards choosing surgical pathology as a future specialty and various factors that influence their choice. Methods: A descriptive cross-sectional study was conducted among a random sample of (209) medical students from (time slot) and com- prised of 1st year to final year MBBS students at various medical universities in Pakistan. A (web-based) self-administered structured questionnaire after validation from experts, was distributed among the students. The collected data was analysed using SPSS version 21. Results: Out of the 209 forms that were distributed, 202 students com- pleted the survey with a response rate of 96.65 %. Almost one third of the students were in third and 4th years of their medical education. The top choices opted by respondents were mainly medicine and surgery and allied specialties. Factors for not opting surgical pathology mainly includes lack of awareness of the importance and role of the specialty in deciding patient therapeutic management. Many of the students were of view that its a basic science specialty with less interaction with patients and physicians. In addition, structured curriculum of MBBS lacks rotation in different sections of pathology. Conclusion: The findings of this multi-institutional study will help us in better understanding the emerging trends among medical students regarding specialty choice. Lack of self-interest in pathology; in par- ticular surgical pathology due to false impression of the subject ’being very tedious with complex histology diagrams’. Interaction with surgi- cal pathology residents & consultants, better understanding of routine workflow by including pathology rotations in curriculum, participation in clinicopathological conferences and multidiscipliniary meetings will help in developing a positive perception in student’s mind. PS-25-003 Haematological indices as potential markers of renal involvement in systemic lupus erythematosus S. Sharma*, S. Farheen, R. Linghaiah, A. Aggarwal *Department of Pathology, SGPGIMS, India Background & objectives: Lupus nephritis develops in approximately 50% of the SLE patients. The study was aimed to evaluate haematologi- cal indices i.e., neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, mean platelet volume and red cell distribution width as potential markers of renal involvement in SLE patients. Methods: In this cross-sectional study of 110 SLE patients, 73 had biopsy proven lupus nephritis (LN). The LN patients were categorized into Class II (n=4), III (n=30), IV (n=16) and Class V (n=23). Uni- variate and multivariate analysis to predict the haematological indices influencing the renal involvement and ROC curve analysis to discrimi- nate patients with LN were performed. Results: The median values of NLR (3.26 vs 1.90), PLR 148.36 vs 104.85) and RDW (20.70 vs 14.20) were significantly high (p<0.05) in LN patients as compared to those without LN. Among haematologi- cal indices RDW showed a significant correlation with S. creatinine (r=0.290, p=0.013) and NLR with S. uric acid (p=0.259, p=0.027). On multivariable analysis, RDW (Adj. OR: 1.45; 95% CI: 1.219-1.716; p<0.001) and PLR (Adj. OR: 1.01; 95% CI: 1.001-1.017; p=0.011) were independent indicators of renal involvement. RDW was the best predictor of renal dysfunction (AUC: 0.811, Cut-off: 14.25%; sensitiv- ity: 91.70%; specificity: 47.40%) followed by MPV (AUC: 0.754), NLR (AUC: 0.719) and PLR (AUC: 0.686) on ROC curve analysis. Conclusion: In our study haematological indices (RDW, Platelet-to- Lymphocyte Ratio PLR, Neutrophil-to-Lymphocyte Ratio NLR and MPV) which are derived from complete blood counts were found to