ECP 2023 Abstracts

S172 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 Funding: Sichuan Science and Technology Program (No. 2022YFS0376). E-PS-03 | E-Posters Cardiovascular Pathology E-PS-03-001 Confusing myxofibrosarcoma of the left atrium, firstly diagnosed as myxoma on biopsy A. Bdioui*, D. Belltaifa, W. Majdoub, M. Krifa, N. Missaoui, S. Hmissa *Sahloul Hôpital of Sousse, Tunisia Background & objectives: Primary cardiac tumours are rare, with an incidence ranging from 0.3% to 0.7%. Despite their usually benign nature, a sound pathological interpretation is crucial to identify malig- nancy. The diagnosis may be challenging, particulary on small biopsy. Methods: The patient, a 32-year-old man, developed signs of dyspnea two months after COVID-19 infection. Computed tomography revealed a left atrial tumour, resection of the tumour was performed. In gross, the received specimen was cramped and of gelatinous texture. Microscopic examination showed abundant myxoid stroma with few non atypical cells, so the diagnosis of myxoma was performed. Results: Six months later, the patient developed left chest pain. Cardiac MRI confirmed tumour recurrence. Meticulous microscopic examination of pathology slides revealed hypercellular area with atypical spindle cells, showing moderate atypia with hyperchromasia and mitosis figure. the stroma was myxoid and abundant. On immunohistochemistry study, tumour cells were focally posi- tive with SMA and CD34, and were negative for myogenic markers, MUC4, PS100 and cytokeratin. Considering the malignancy signs and the immunohistochemistry profile, the diagnosis was rectified for myxofibrosarcoma. Conclusion: Myxoid tumour are diagnosis challenging lesion, an expanded sampling, a meticulous microscopic examination and an appropriate immunohistochemical study are crucial to avoid wrong diagnosis. E-PS-03-002 Fatal outcome of a unique case: primary cardiac angiosarcoma with lipoblastic differentiation discovered in a young athlete – case report A. Ciongariu*, A. Dumitru, D. Tapoi, A. Bejenariu, M. Sajin, V. Ionita, C. Badiu, M. Costache *Department of Pathology, University Emergency Hospital Bucharest, Romania Background & objectives: Cardiac angiosarcoma is an exceedingly rare high-grade malignancy with an aggressive clinical behaviour and rapid extension to the pericardium and mediastinum. Angiosarcomas can disclose significantly variable histomorphology, occasionally mim- icking divergent lesions with mesenchymal or epithelial differentiation. Methods: We report the case of a 21-year-old male basketball player who developed cardiac failure and was referred to the Cardiovascular Surgery Department. Further examinations identified a mediastinal tumour mass arising in the atria and infiltrating the ascending aorta and superior vena cava. Several samples from the tumour and the pericardial fluid were collected and submitted for histopathological examination. Results: The microscopic examination revealed a malignant mesenchy- mal proliferation consisting of round-oval, epithelioid and spindle cells with pleomorphic nuclei and mitotic figures. Poorly formed, irregular vascular spaces were noted within the tumour proliferation. Moreover, the microscopic examination showed atypical cells with lipoblastic differentiation, exhibiting intracytoplasmic vacuoles and hyperchro- matic nuclei. Upon immunohistochemical analysis, we identified strong ERG and CD31 expression within the tumour cells with endothelial phenotype, while the atypical lipoblasts showed intense S100 staining. Expression of CDK4, MDM2 and CD45 was absent in the malignant cells. Thus, the diagnosis of angiosarcoma was eventually established. The patient died a few days later due to severe complications of the condition. Conclusion: Mediastinal tumours in young patients can be a chal- lenging diagnosis, considering their rarity and variable morphology. The most common malignant tumours of this region are lymphomas, carcinomas and vascular lesions. Although an uncommon finding, lipo- sarcoma of the mediastinum can also be discovered in young patients and should be considered for differential diagnosis. Microscopic and immunohistochemical studies should be performed and thorough corre- lation with the clinical data is recommended. Awareness of this disease is crucial in preventing misdiagnosis and improper treatment. E-PS-03-003 Fatal case of giant cell myocarditis with near total myocardial fibrosis in a 40 year old woman H. Goebel*, T. Tsvetkov, C. Grathwohl, A. Deppe *Institute for Pathology, University Hospital Cologne, University of Cologne, Germany Background & objectives: Giant cell myocarditis is a rare disease with an incidence of 0.007% and 0.051%. Methods: We present a case of a previously healthy and sportive woman. After a bout with Covid19 the woman consulted a hospital with unclear unwellness. An highly reduced ejection fraction without sign of ischemic heart disease was found and she was admitted to the cardiothoracic centre of our hospital with suspicion of a myocarditis. Results: Her health deteriorated rapidly leading to an inital implanation of an impella device and a myocardial biopsy showed a giant cell myocar- ditis. The patients condition worsened leading to ECMO and finally to the implantation of a Berlin Heart device. A second biopsy seen at our depart- ment only showed a very expanded interstitial fibrosis and hypertrophic myocytes but no active lymphocytic or giant cell infiltration. Extensive bleeding within the bronchial tree led to further desoxygenation and finally demise of the patient. At autopsy an enlarged heart with hypertrophy, fresh haemorrhage up to the alveolar spaces and very extensive fibrosis of the myocardium without presence of giant cells or other inflammation was notable. Conclusion: An ongoing infection of Covid 19 within the lung could be excluded by pcr testing. We present a case of a giant cell myocarditis with a very short timespan leading to a subtotal fibrosed heart with fatal insufficiency. A Covid- 19-association could not be established. E-PS-03-004 Forensic anatomo-pathological death investigation of heart trans- planted victims R.H. Henriques De Gouveia*, C. Marques, J. Barata, F. Corte Real *Universidade da Madeira, Portugal Background & objectives: Heart Transplantation is the final ther- apy for end-stage heart failure (HF), leading to morbidity/life quality improvement and to mortality reduction of irreversible HF patients. Authors aim to present how forensic anatomo-pathological study con- tributes to death investigation of post-heart transplantation victims. Methods: A retrospective study of postmortem examinations per- formed at two branches of our National Medico-Legal Institute during a time span of 17 years, searching post-heart transplantation deaths, was done. Results: Three cases were found: 1 female (21 years-old), 2 males (55 years-old, each); deceased suddenly, out-of-hospital, due to acute