ECP 2023 Abstracts

S346 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 Pulmonary carcinosarcoma is a biphasic tumour with an unfavourable prognosis. The differential diagnosis includes pulmonary blastoma and is often challenging. Methods: We here describe a case of blastomatoid pulmonary carci- nosarcoma in a 68-year-old patient, who underwent surgical lobectomy of left upper lobe. The tumour size was 60x58x40mm. Histopathologi- cal examination revealed immature glandular epithelium resembling high-grade foetal adenocarcinoma expressing epithelial markers and membranous beta-catenin, and blastomatoid spindle cells with rhab- domyosarcoma differentiation. Results: The tumour was composed of areas of glandular differentia- tion and immature spindle cell areas with a sharp border between both. The tumour exhibited an extensive necrosis (about 70% of tumour). The epithelial component, accounting for 75% of the viable tumour, showed a branching immature gland composed of columnar cells with palisading elliptic nuclei with subnuclear vacuoles. The epithelial cells have a focal an immunoreactivity for glypican-3 and SALL4, but, not in CK7 and TTF-1. Staining for beta-catenin demonstrated a membranous expression. The spindle cells expressed desmin and myogenin indicat- ing rhabdomyosarcoma-like differentiation. A STX-SS18 fusion pro- tein was not detected. Next generation sequencing showed no EGER, KRAS, ALK, ROS1, and CTNBB1 mutation. Conclusion: The diagnosis of the blastomatoid variant of pulmonary carcinosarcoma was established and the tumour was finally staged at pT3, pN0 (0/15), pMX. Currently the patient is doing well and there is no evidence of tumour relapse 30 months after the resection. The presence of high-grade foetal adenocarcinoma without TTF-1 expres- sion and absent nuclear expression of beta-catenin in a biphasic lung tumour in adult patient favour the diagnosis of blastomatoid pulmonary carcinosarcoma. E-PS-21-033 Pulmonary histoplasmosis mimicking metastatic lung cancer: a case report D. Nunes Oliveira*, P. Vianna Caldas Ribeiro, R. Vilar Lima, H. Neves Feitosa Filho, D. Vianna dos Santos, J. Carneiro Melo, F. Rocha Fer- nades Távora, I. Santos Costa *University of Fortaleza, Brazil Background & objectives: Infection with the thermal dimorphic fun- gus Histoplasma capsulatum (Hc), when found in the form of pulmo- nary nodules, can become indistinguishable from malignant disease on imaging examinations. Here we report a case of Hc with initial presentation of multiple pulmonary nodules. Methods: Report a case of a 53-year-old man living whose diagnosis of histoplasmosis was delayed since the findings had been initially misinterpreted as pulmonary malignancy. Results: Male patient, 53 years old, presented with high fever, sporadic dry cough, weight loss of approximately 6 kg in 15 days. Initial results, including serologies and histopathological study of a lung biopsy guided by computed tomography, which found mul- tiple pulmonary nodules associated with hilar lymph node enlarge- ment, were inconclusive and negative. Although there was clinical improvement, the tomographic changes persisted. This led to a sec- ond biopsy by thoracotomy, which confirmed the diagnosis of fungal infection by Histoplasma capsulatum together with the positivity of new serologies. Conclusion: This case highlights the need to consider Histoplasma capsulatum, a fungus, as a potential cause of pulmonary nodules since its imaging appearance can mimic that of malignant disease. A 53-year- old male patient presented with symptoms and conflicting initial test results, but a thoracotomy biopsy confirmed the diagnosis of Histo- plasma capsulatum infection. The case underscores the importance of a comprehensive evaluation and a high degree of suspicion when trying to differentiate between infectious diseases and cancer in patients with pulmonary nodules. E-PS-21-034 Analysis of asbestos body count in the lungs of female patients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy K. Okabe*, H. Kinoshita, N. Furukawa, H. Komatsu *Bell Land General Hospital, Japan Background & objectives: Malignant pleural mesothelioma (MPM) is well known as very poor prognosis and related to asbestos inha- lation. This study analysed the asbestos body count in the lungs of female patients with MPM who underwent extrapleural pneumonec- tomy (EPP). Methods: Among 60 consecutive EPP cases for MPM from 2006 to 2019, eleven patients of female MPM were reviewed. Asbestos body quantification involved the digestion of 1-4 grams of lung tissue in bleach employing a modified Smith and Naylor method (Am J Clin Pathol 1972; 58:250-254). In addition, age, MPM type, affected side, cause of asbestos exposure, and prognosis were investigated. Results: The median age at EPP was 60 (46 - 68) years old. The epi- thelioid type was 9, and the biphasic type was 2. Right side was 7, and left side was 4. Four patients had occupational asbestos exposure in asbestos factory, casting factory, and architect office. Four patients were judged as environmental asbestos exposure. However, asbestos exposure was unknown in three patients. The prognosis was greatly improved, and 5-year survival rate and median survival time of nine female patients with epithelioid MPM were 67% and 70 months, respectively. The median asbestos body count in one gram of dried lung was 4027 (range: lower than the detection limit - 443571). Conclusion: Relationship between asbestos and female MPM was re- confirmed. The median asbestos body count in one gram of dried lung of female MPM was 4027. The asbestos body counts of occupational exposure were 443571, 51073, 7169, and lower than the detection limit. The asbestos body counts of environmental exposure were 5911, 4027, 2340, and 265. Although the dried lung of MPM were investigated, the asbestos body counts of 36% were less than 1,000/g, and those of 45% were more than 5,000/g. E-PS-21-035 Ambivalent aspects of TNF-α in relation with proinflammatory cytokines in patients with COPD D. Pasarica*, F. Toparceanu, M. Gheorghiu, L. Ichim, M. Serban *“Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania Background & objectives: Cytokines are important in responses to COPD. We investigated the dynamics of cytokines IL-8, IL-6 and TNF-α in the serum of patients with COPD to understand the behav- iour of TNF-α in relation to the stages of the disease. Methods: 20 patients (4 women and 16 men) with COPD (mean age 61.0±14.19 years), smokers for more than 20 years were recruited for our study. 10 patients were classified as having GOLD stage II, 10 patients as having GOLD stage III. Serum sample was evaluated by ELISA kit. Pearson correlation coefficient (r) was calculated. Results: The percentage of circulating neutrophils was 64±5,19% in GOLD II(FEV174-55%) and 73±1.69% in GOLD III(FEV154-35%). IL-8 correlated positively with TNF-α (r=0.539 p=0.05) and IL-6 (r=0.554 p=0.02) in patients with GOLD II. On the contrary IL-8 correlated positively with IL-6 (r=0.777 p=0.05) but not with TNF-α in patients with GOLD III.These suggest that IL-8 and IL-6 can modulate the action of TNF-α towards apoptosis through the TNFRI receptor involving JNK on neutrophils infiltrating in GOLD II. In COLD III the lack of correlation between IL-8 and TNF-α but the presence of a positive correlation between IL-8 and IL-6 suggests that apoptosis by TNF-α is reduced explaining the neutrophilia in GOLD III.