ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 immunofluorescence showing a significant increase of tryptase- and chymase positive cells in COVID-19 as well. Furthermore, AGER (receptor for advanced glycation end-products) and PPBP (pro-platelet basic protein) were upregulated in COVID-19 com- pared to influenza. IFIH1, IFI44L, IFIT1, and RSAD2, genes related to type I interferon signalling, showed a significant cor- relation to detected SARS-CoV2 pathway-related genes. A com- parison of groups based presence of histomorphological features indicative of ARDS did not show upregulation of any specific gene or pathways. Conclusion: Through two separate ways of measurement, we show an increase of mast cells in lungs affected by severe COVID-19 compared to influenza. Additionally, several genes involved in fibrosis and thrombosis, among which are AGER and PPBP, are upregulated in COVID-19. Future studies should focus on detecting these markers in bronchoalveolar lavage fluid to predict the severity and course of the disease. PS-23 | Poster Session Neuropathology PS-23-001 Expression of LAMP2A, LC3B, and HSP70 autophagy bio- markers in different brain structures during aging A. Magnaeva*, T. Baranich, A. Gofman, D. Voronkov, V. Sukhorukov *National Medical Research Center for Obstetrics, Gynaecology and Perinatology named after Academician V.I.Kulakov, Russia Background & objectives: Macroautophagy and chaperon-mediated autophagy play a pivotal role in misfolded proteins removal in neurons, whilst their impairment contributes to aging and age-related diseases. We aimed to evaluate biomarkers of abovementioned processes in neu- rons localized in different brain zones during aging. Methods: Heat shock protein 70, LAMP2A, and LC3B immuno- histochemical staining was performed for FFPE samples of human prefrontal cortex (pyramidal layer), hippocampus, and basal ganglia. Two age groups were studied: young (n=5) and elderly (n=10),whose causes of death were not associated with neuro- logical diseases. The optical density was measured in neuronal perikaryon. Statistical significance was analysed using Kruskal Wallis test. Results: From the obtained data, it is apparent that in studied groups there was significant difference between macroautophagy (LC3B), chaperon-mediated autophagy (HSP70), as well as lysosome receptor (LAMP2A) biomarkers expression in neuronal perikaryon of large neurons (p<0.05). Statistical test revealed increased levels of these autophagy-lysosome pathway proteins in elderly studied groups than in young one. Interestingly, the level of HSP70 in elderly samples was 2-fold higher in comparison with samples obtained from young group. The rates for LC3B and LAMP2A for elderly group were approximately 1.25 times higher than young group, but optical density in each brain zones were not found to differ. Conclusion: Our demonstration that Heat shock protein 70 expres- sion was significantly increased in elderly samples could indicates its potential role in adaptive mechanisms occurring in aging neu- rons during chronic oxidative stress and inflammation. Exacerbated levels of all autophagy biomarkers in elderly samples as to young one points out that autophagy seems to support proteostasis in neu- rons during physiological aging. These findings, while preliminary, suggest that both autophagy-lysosome pathways could contribute to neuronal maintenance during aging. PS-23-002 Prognosis and outcome of patients with haemangioblastoma based on histopathological features: experience of a tertiary centre F. Leiva-Cepas, J. Osuna Soto*, M.J. Gálvez Medina, I. Sánchez Ramírez, R. Ortega Salas *Reina Sofía University Hospital in Córdoba, Spain Background & objectives: Haemangioblastoma is a highly vascular tumour of the central nervous system with clear neoplastic stromal cells, classified as WHO Grade I. The aim of the present study is to investigate the clinical manifestations, histopathological features and prognosis of this entity. Methods: The characteristics of 25 patients diagnosed of haeman- gioblastoma were analysed, and a retrospective review of heman- gioblastoma of the central nervous system reported in the literature was performed. Results: 12 patients were female and 13 were men, aged from 9 to 77 years (55 years on average). All cases were wild-type sporadic, except for one associated to Von Hippel Lindau Syndrome. 15 cases were located on cerebellum, 9 on the brain and one on spinal cord. Microscopically, the morphology and immunophenotype of tumoral cells were not different from those mentioned in the literature. 3 patients died during the follow-up period and 4 patients suffered a recurrence of the disease. Conclusion: Overall prognosis was relatively good, so the presence of tumoral recurrence or malignant transformation was unusual. The most common presentation is a sporadic tumour located on cerebellum. From an histological point of view, only the presence of atypical mitoses correlated with progression of the disease. Cerebral haemangioblastoma often simulates the imaging characteristics of meningioma or gli- oma. Enough attention should be paid to differential diagnosis before the operation, and exact diagnosis relies on the patho- logical examination. PS-23-003 Retrospective multicentric study of patients with histopatho- logical rhabdoid meningioma features A. Pasco Peña*, M.V. Zelaya, M.C. Caballero, M. Gonzalez-Tablas, A. Otero, J. Ortiz, M.D. Ludeña, M.D. Tabernero *Hospital Universitario de Navarra, Spain Background & objectives: Rhabdoid meningiomas (RM) are WHO grade 3 brain tumours, with high rates of local recurrence and heterogeneous mortality. Our aim is to analyse the clinical and pathological characteristics and to establish a possible correlation with the aggressive clinical course. Methods: We have reviewed the histological, clinical and progno- sis characteristics of patients with MR from 17 Pathology Depart- ments and 4 biobanks of Spain. We also review the mitotic index, immunohistochemistry and diagnosis. In cases with aggressive behaviour or successive relapse, we consider to combine a genetic profile through high-density arrays looking for specific genetic abnormalities (loss and gain of chromosomal regions). Results: From 24 patients only 17 met histological criteria for MR. The age range was 34 to 83 years(10 men, 7 women). In the follow up, we observed 5 RMs with aggressive behav- iour, multiple episodes of recurrences and death of the patients (5/17, 3 deceased without recurrences). The sequential analysis of the evolution and genetic changes included tumours at diag- nosis and relapse samples. In 2/5 tumours, the genetic pattern at relapse remains identical to that at diagnosis and in the other S161