ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 autopsies generally, among them 146 foetal. Based on autopsy findings, we identify the most common causes in perinatal death. Data were analysed using methods of descriptive statistics. Results: The clinical diagnoses were: anomalies 45, intrau- terine death 42, chromosomal aberrations 18, placental and umbilical lesions 10, spontaneous abortion 2, tumour 3 and multiple causes 26. Autopsy confirmed anomalies are the most frequent primary disease and cause of death (56%), where CNS anomalies were leading lesions (41%). Based on patohistology general asphyxia is the following cause of foe- tal death in 47%. Asphyxia was associated mostly with pla- cental lesions (37%) as a result of vascular placental changes, followed by inflammation in women older than 35 years. We found the highest association of chromosomal aberrations in the same mother’s ages. Foetal anomalies were mostly found in women younger than 25 years. Conclusion: Anomalies and asphyxia are the most frequent cause of foetal death between 26-35 gestation weeks. Foetal asphyxia as a result of placental ischemic lesions, umbilical cord pathology is mostly seen in mothers older than 35 years. In the same age group were mothers of foetuses with chromosomal aberrations. Foetal anomalies are mostly found in mothers younger than 25 years. PS-06-005 The association of mir-204 and mir-483 5p expression with clinicopathological features of Wilms tumour: could provide foresight? A. Orgen Calli, G. Issin, İ. Yılmaz, D. Ince, I. Guzelis*, E. Tural, R.E. Cecen, H.N. Olgun, D. Kabakci, E. Ozer *Izmir Katip Celebi University, Turkey Background & objectives: Wilms tumour(WT) is the most com- mon neoplasm of the kidneys in childhood. With the improvement of up-to-date treatment protocols, an increase in survival rates in WT was observed. However, metastases or local relapses are still observed in 15% of patients. Methods: The evaluation of genetic and epigenetic features such as miRNA analyses might allow us to comment on the behaviour of the tumour and the treatment response. For this purpose, expression levels of mir-204 and mir-483-5p were evaluated in tumoral and normal tissue by qRT-PCR. The relationship of miRNA expression levels with clinicopathological, histological features, and survival was also investigated. Results: This study recruited 24 WT cases who had paraffin blocks available for the study. Anaplasia (focal and diffuse) was identified in six patients(12%) based on the distribution of anaplastic changes. The result of the study indicated that the relative expression levels of mir-204 in WT tissues were significantly lower than that in adjacent normal tissues(mean value0.11). In contrast, tumour tissue had higher miR-483-5p expression than corresponding normal tissues. A statistically significant association between miR- 204 expression level with age and the presence of anaplasia was observed in this study. Significantly high levels of miR-483-5p expression were found in cases who underwent preoperative CT compared to those who did not receive CT. Conclusion: According to the literature data, decreased expression of miR-204 is associated with a poor prognosis. Our findings also suggest that poor prognostic data are accompanied by a downregu- lation of miR-204. In our study mir-483-5p expression level was found to be higher in patients who underwent preoperative CT compared to patients who did not receive CT. Of particular interest is the finding that the mir-483-5p can be a promising biomarker in the early detection of CT response in WT. PS-06-006 Histopathological assessment of placenta in maternal SARS- CoV-2 infection R.A. Balan*, I.D. Caruntu, I. Pavaleanu, T. Butureanu, M. Pavaleanu, D. Popovici, S.E. Giusca, L. Lozneanu, T.A. Balan, C. Amalinei *"Grigore T. Popa" University of Medicine and Pharmacy, Romania Background & objectives: The placenta represents an important witness of pregnancy and its related complications in SARS-CoV- 2-infected mothers. We aim to evaluate specific histopathological placental changes associated with maternal SARS-Cov-2 infection and their correlation with pregnancy dynamics. Methods: The study includes 36 pregnant women, with pregnancy age ranging from 11 to 42 weeks, admitted between September 2020 and February 2022 with positive nasopharyngeal RT-PCR for SARS-CoV-2. All placenta specimens were macroscopically and histologically examined, the slides being conventionally stained with Hematoxylin and Eosin and immunohistochemically stained for CD8, CD68, and CD20. Results: Of the 36 women, 34 (94.44%) had singleton pregnancies, one (2.77%) had twin pregnancy, and one (2.77%) had quadruplets. 28 (77.77%) pregnancies were term deliveries, with one (2.77%) placenta accreta and one (2.77%) marginal placenta praevia, two (5.55%) were miscarriages, and 4 (11.11%) were foetus exitus. The histopathological assessment revealed chorioamnionitis in 9 (25%) cases, foetal vascular malperfusion in 15 (41.66%) cases, villitis and chronic intervillositis in 8 (22.22%) and 4 (11.11%) cases, chronic deciduitis in 4 (11.11%) cases, hematomas in 7 (19.44%) cases, infarction in 11 (30.55%) cases. All placentas showed an association of these abnormalities, the local inflammatory response being underlined by positive immunoexpression of studied markers. Conclusion: SARS-CoV-2 infection in pregnant women is associated with an increased frequency of placental histopathological abnormalities, especially foetal vascular malperfusion, various inflammatory lesions, infarction, and hematomas. In complicated pregnancies of patients with SARS- CoV-2 infection, histopathological evaluation of the placenta, supported by a specific panel of antibodies, may help elucidate the pathological mechanisms that occur at the foetal-maternal interface associated with COVID-19 infection, providing additional data in the obstetrical management of this pathology. PS-07 | Poster Session Digestive Diseases Pathology - GI PS-07-001 Podoplanin expression in neoplastic cells and cancer-associated fibroblasts in colorectal cancer predicts unfavourable clinico- pathological features R. Souza da Silva*, E. Queiroga, C. Osório, K. Cunha, E. Dias *Universidade Federal da Paraíba, Brazil Background & objectives: The pattern of activity of the cellular elements that compose the tumour microenvironment influences tumour behaviour. To analyse the activity of cancer cells (CCs) and cancer-associated fibroblasts (CAFs) in colorectal cancer (CRC), based on the expression of podoplanin stratified by tumour-stroma ratio. Methods: We performed immunohistochemistry for podoplanin on tissue microarrays from 357 cases of colorectal adenocarcinoma (CRA). The tumour-stroma ratio (TSR) was evaluated: stromal per- centage ≤50%- stroma low; >50%-stroma-high. The expression of podoplanin was evaluated in different areas: TSR, most invasive, centre of tumour, tumour budding, and desmoplastic stroma. The S90