ECP 2023 Abstracts

S118 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 Methods: We reviewed the digitalized preparations of 39 cases diag- nosed in our centre between 2001 and 2023, as well as the medical history, and prepared a table with the histologic data and relevant char- acteristics. Stoken’s classification was used as a reference. Results: 39 cases reviewed, 23(59%) were boys and 16(41%) girls. The age range was between 18 weeks of gestation and 16 years, being more frequent in the first year of life. The review diagnoses were: CPAM 1: 6 cases (15.4%), CPAM 2 or bronchial atresia sequence 24 cases (61.6%), in which 4 cases (17.4%) the atresia was identified, CPAM 3: 1 cases (2.5%), CPAM not classifiable: 8 cases (20.5%). The following differential histopathological features were observed between type 1 and type 2. Groups of mucinous cells (p<0.005) CPAM1 5 cases (83.3%) and CPAM2 2 cases (8.3%). Signs of obstruction (p<0.001) CPAM1: 1 case(16.7%) and CPAM2: 16 cases (67%). Presence of lymphoid com- ponent (p<0.001) CPAM1: 2 cases (5%), CPAM2: 18 cases (46%). Conclusion: The historical classification of CPAM is confusing and poorly replicable. In our series, We conclude that groups of mucinous cell are important for CPAM 1 and signs of obstruction and lymphoid component for CPAM 2 or bronchial atresia sequence. In foetal lesions the classification is very limited by the maturational stage of the lung. The other histological parameters such as epithelial lining, size of the cyst or wall, presence of smooth muscle in our series were not statisti- cally significant (p>0.05). PS-19-005 Placental pathological assessment in a SARS-CoV2 maternity ward of the Romanian National Institute for Mother and Child Health T.G. Jaswal*, T. Georgescu, A. Ro ș ulescu, A. Georgescu, A. Cernat- Stefan, R. Pletosu, M. Sajin *Department of Pathology, University Emergency Hospital Bucharest, Romania Background & objectives: Since the coronavirus disease outbreak, there was increased interest in the spectrum of inflammatory-hypoxic- thrombotic abnormalities during pregnancy. In this study, our objective was to investigate the placental signs of foetal (FVM) and maternal vascular malperfusion (MVM) contribution to foetal development. Methods: We analysed 39 placentas delivered between 2020 and 2022 by pregnant women confirmed with SARS-CoV2 infection using RT- PCR. We applied the Amsterdam Placental Workshop Group Consen- sus recommendations and categorized the histopathological findings into three major groups: MVM, FVM and inflammatory lesions. Sta- tistical analysis was performed using SPSS. T test and Chi-square test were used to compare study and control groups. Results: All placentas were from third trimester live births, except for one intrauterine foetal demise in the second trimester. Statistically significant differences were observed among MVM findings of SARS- CoV2 placentas and controls: decidual arteriopathy (p=0.016), perivil- lous fibrin deposition (p=0.033), Tenney-Parker-Change (p=0.008). Among FVM signs there was a higher frequency of avascular villi (AV) (p=0.001), foetal-circulation thrombi (p=0.003), subchorionic vascu- lar ectasia (p=0.001), delayed villous maturation (DVM) (p=0.036). Deciduitis was observed in 40% cases (p=0.021) and villous oedema in 52.5% (p=0.004). We found that in newborns of SARS-CoV-2-positive mothers, the Apgar score was lower in the presence of AV (p=0.044) and the weight was lower in the presence of DVM (p = 0.039). Conclusion: Our study revealed that there is an increased prevalence of both maternal and foetal vascular malperfusion as well as inflammatory lesions among the placentas from women infected with SARS-CoV2, compared to the control group. There may be a cascade of pathological anomalies starting with the hypercoagulable state of the SARS-CoV2 positive mothers following hypoxic changes and ending with injury of the placenta. Future research should assess the correlations between these histopathological findings and the impact on pregnancy outcome. PS-19-006 Placental pathology and clinicopathologic correlation in kidney transplant patients: tertiary centre experience H.S. Toru*, B. Altunay, D.M. Chiorean, G. Bulbul, C.Y. Sanhal, I. Mendilcioglu *Akdeniz University, Turkey Background & objectives: There is a limited number of studies in the literature on whether there is a difference in the histopathological examination of placental findings in pregnancies of kidney transplant patients compared to the average population. Methods: We aim to contribute to the literature by comparing the placen- tal pathology with control groups. Retrospectively, pathology archive was reviewed, and 16 kidney transplant patients’ placenta were included in the study. We selected 32 cases in term placenta control group and 32 cases in control group at the same gestational age in kidney transplant group. Results: Among 80 cases, 36.3% of mothers had a clinical disease. Mean age was 29.81 (std: ± 3.33) kidney transplant group, 29.97 (std ± 8.46) same gestational age control group, 29.88 (std: ± 6.20) term con- trol group. Placental pseudocysts were significantly higher in the kidney transplant group than in both control groups (p<0.01). Chorionic pseu- docysts were seen higher in kidney transplant group than control groups, but the difference was insignificant (p=0.140). The difference between groups in amniotic fluid infection sequence was insignificant (p=0.268). IUGR were similar in kidney transplant group and same gestational age group; both were significantly higher than the term group (p=0.001). Conclusion: Pregnancy complications in kidney transplant patients are higher than in the general population. For this reason, patients with kid- ney transplantation should be followed carefully, and a multidisciplinary approach should be applied with nephrologists or organ transplant physi- cians, midwives, and obstetricians. In addition, placenta gives important data related to pregnancy process, maternal and foetal progress. In conclusion, if placental data are widely evaluated and meta-analyses are made, follow-up and treatment protocols specific to kidney trans- plant pregnancies can be improved and developed. PS-20 | Poster Session Pulmonary Pathology PS-20-001 Correlation between morphology and next generation sequencing in multiple lung adenocarcinomas, our experience in 24 patients I. Amat Villegas*, D. Guerrero-Setas, A. Panizo Santos, T. Labiano Miravalles, C. Cerezo Aguirre, M.R. Mercado Gutierrez, V. Zelaya Huerta *Spain Background & objectives: The distinction between intrapulmonary metastases, synchronous primary tumours and metachronous multi- ple lung adenocarcinomas are often challenging. Main basis for this purpose are the histological features of the different nodules but next generation sequencing (NGS) is becoming a useful tool too. Methods: We retrospectively analysed a series of 24 patients with two or more lung adenocarcinomas, synchronous or metachronous. Two pathologists with special interest in thoracic pathology reviewed the histological slides and Focus NGS was performed on all of them. A staging was proposed for each form of evaluation and the correlation between both was studied. Results: A total of 54 lung adenocarcinomas from 24 patients have been evaluated by reviewing histological slides of resected specimens and a suggested staging for 21 patients was done. Seventeen tumours were synchronous and nine metachronous, three patients had more than two nodules. Concordance between molecular results in different tumour nodules of a patient was found consistent with tumour metas- tases. Correlation between morphological and molecular staging was found in 19 cases.