ECP 2023 Abstracts

S33 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 OFP-08-011 SARS-CoV-2-related mortality – an autopsy study C. Schwab*, U. Merle, P. Schirmacher, T. Longerich *University of Heidelberg, Institute of Pathology, Germany Background & objectives: For the management of the COVID-19 pandemic it is important to discriminate who died due to COVID-19 or due to another disease while being infected. We addressed this ques- tion and compared COVID-19-related lung damage during the course of the pandemic. Methods: From March 2020 to December 2023 a total of 117 autop- sies were performed according to a standardized protocol on decedents with proven SARS-CoV-2 infection. COVID-19-related lung damage was semiquantitatively assessed for the exudative, proliferating and fibrosing component, respectively. The cause of death was assessed in synopsis of all autopsy findings and clinicopathological data. Results: The characteristic sequence of COVID-19-related lung injury was preserved during the pandemic, but there were differences between the individual waves of infection related to the evolution of various virus variants. In decedents infected by an Omicron variant the lung damage was less severe and significantly less often the cause of death compared to precedent variants (p<0.05). COVID-19-related death was not recorded in patients being re-infected or having received a booster vaccination. Conclusion: Autopsy is a valuable tool for evaluating the outcome of a SARS-CoV-2 infection. According to our findings infections with an omicron variant is rarely causative of death, which is highly relevant for the management of the COVID-19 pandemic. The study was funded by the Ministry of Science, Research and Art of Baden-Württemberg (Baden-Württemberg Corona Autopsy Biobank and Registry). OFP-08-012 Sudden death due to hydatid disease: a histopathological analysis E. Gun*, M.C. Yazici, B. Gun, T. Das, I. Coban *Basildon University Hospital, Mid and South Essex NHS Foundation Trust, Basildon, Essex, United Kingdom Background & objectives: Caused by the parasite Echinococcus granulo- sus, hydatid disease (HD) is an important public health problem in endemic regions. Rarely, cysts may rupture, leading to anaphylactic shock and sud- den death. We aimed to identify cases of sudden death caused by HDs. Methods: Cases that underwent autopsy between January 2010 and July 2022 and were diagnosed with HD based on histopathological examination were retrospectively examined along with their histopatho- logical findings. The demographics, the localization and characteristics of the cysts, and the causes of death were reviewed. Cases that resulted in sudden death due to HD were identified. Results: Of the 91 cases identified with HD, 64 were males and 27 were females, with a mean age of 42.1 years (8-89). The majority of the cysts were located only in the liver (n=67), and cysts were found in multiple organs in 12 cases, including the lungs, heart, kidney, bladder, pancreas, spleen, and gallbladder. Fifteen cases (16.4%) were attributed to HD and its complica- tions as the cause of death. Anaphylactic reaction caused sudden death in nine cases, and histopathological examination revealed scolices in the pul- monary vessels in eight of these cases. Five sudden death cases had a cyst in the heart, and two had scolex emboli in the cerebral vessels. Conclusion: Even though HD most commonly affects the liver and lungs, it can affect many other organs. In conclusion, the present study suggests that HD can lead to serious complications including sudden death, particularly when the scolices enter the circulation causing anaphylactic shock. Histopathological examination of autopsy cases is important in determining the cause of death in HD. The findings of this study may contribute to raising awareness of the risks associated with HD and its potential complications, especially in endemic regions. OFP-09 | Oral Free Paper Session Breast Pathology OFP-09-001 Breast-conserving surgery in invasive lobular carcinoma of the breast after neoadjuvant chemotherapy J. Azevedo*, M. Alzamora, A. Coutada, A. Lapa, L. Gonçalves, N. Coimbra, C. Leal *Pathology Department, IPO-Porto, Portugal Background & objectives: The surgical management of invasive lobu- lar carcinoma (ILC) after neoadjuvant chemotherapy (NAC) is contro- versial due to its distinctive characteristics, which may lead to preop- erative underestimation of disease extent. We evaluated frequency of breast-conserving surgery (BCS) and need of surgical re-intervention. Methods: Cases diagnosed with ILC who underwent surgery follow- ing NAC between 2011 and 2021 were identified through a review of internal records. Data recorded included patient age, radiological findings (pre- and post-chemotherapy) and type of surgery. The need for re-excision lumpectomy (with margin status) or complementary mastectomy was recorded. Results: In total, 115 cases were included with 29 (25.2%) undergo- ing BCS and 86 (74.8%) mastectomy. In the cases of BCS, 11 (37.9%) showed radiological complete response and 8 (27.6%) marked reduc- tion in size. Eleven cases (37.9%) performed margin widening intraop- eratively. In the final pathology report, 2 cases (6.9%) had pathological complete response. Regarding margin status, 14 (48.3%) were positive and 9 (31.0%) were close (<1mm). Subsequently, 7 (24.1%) patients were submitted to re-excision lumpectomy and 10 (34.5%) to mastec- tomy. Of these 17 patients, 11 presented residual invasive carcinoma (RIC). One patient required a third surgery, modified radical mastec- tomy, still showing RIC. Conclusion: NAC is a well-established treatment option in breast can- cer in order to obtain tumour downsizing, allowing BCS, and achieve tumour downsizing/pathological complete response, however its role in ILC is controversial. Additionally, accurate preoperative staging and monitoring NAC response in ILC remains challenging. More than half of the patients require a second surgery either re-excision lumpectomy or complementary mastectomy, to achieve tumour-free margins. Also, intraoperative margin widening during BCS does not reduce the need for further surgeries in patients with RIC. OFP-09-002 Analysis of discordant cases between tumour grade and risk cat- egorisation using EndoPredict® in breast cancer V. Macarrón Aguilera*, A. Peláez-García, J.I. Sánchez-Méndez, L. Yébenes, A. Berjón, D. Hardisson *La Paz University Hospital, Spain Background & objectives: EndoPredict® is a genetic test that predicts relapse risk in ER+/HER2- breast cancer by combining genetic and clinicopathological data (EpClin). We aim to assess cases where there is a discrepancy between tumour grade and genomic risk classification (EPClin high/low-risk). Methods: EndoPredict® has been utilized in our centre on 323 patients since 2015. We reviewed the EP (genomic index), EPClin (EP com- bined with tumour size and lymph node status, pN), and tumour grade to identify discordant cases. Furthermore, we examined the prolifera- tion index (Ki67) and genomic profile (proliferation genes of EP index). Results: In total, we identified 20 cases with low tumour grade and high-risk EPClin (G1 HR) and 15 cases with high tumour grade and low-risk EPClin (G3 LR). In G1 HR, the genomic profile was high-risk in 19 cases (95%). 45% of these tumours were >20 mm, and 70% were pN+. However, Ki67 index was ≥20% in only 9 cases (45%). On the other hand, in G3 LR, 87% of tumours had a high-risk genomic profile. In these cases, the clinicopathological features of the tumours shifted