ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Background & objectives: Entire exome sequencing studies of DLBCL tissues have identified MYD88 and PIM-1 genes as involved in the development and signalling of this pathology. We aim to genotype profiles of MYD88 and PIM-1 genes and their implications on the prognosis. Methods: We have conducted a retrospective study that included 50 paraffin-embedded tissues of DLBCL diagnosed at the Pathol- ogy Department of the Emergency County Clinical Hospital, Con- stanta, Romania, and Sacele Municipal Hospital, Brasov, Romania, between 2012 and 2021. The genotyping was analysed by RT-PCR using TaqMan® genotyping master mix and readymade TaqMan® genotyping assays for MYD88 (p.L252P) and PIM1 (p.G28A, p.L184V, p.V197F) Results: Twenty-two patients were female and twenty-eight were male with ages ranging from 26 to 91 (mean:60,32 years).Twenty- four tumour samples were located in the lymph nodes and spleen, sixteen were located in the gastrointestinal tract (GI), four were located in the central nervous system and six tumours were located in the skin, testis, head and neck. Four cases (8%) were found to have mutation p.Leu252Pro in the MYD88 gene which occurs due to the transition of T>C at c.755 and only one case (2%) was found to have a mutation p.Gly28Asp in the PIM1 gene, as a transition of G>A at c.83. Conclusion: In conclusion, our preliminary data suggests that the oncogenic mutations of PIM1 and MYD88 in our diffuse large B-cell lymphoma (DLBCL) cohort may improve diagnosis and prognosis of the patients with this pathology. Funding: This study was funded by ”Grants competition in the bio-medical field 2021”, Contract no. 5/21.10.2021, registered at ”Ovidius” University of Constanta with no. 14453/21.10.2021. This research was performed in the Center for Research and Devel- opment of the Morphological and Genetic Studies of Malignant Pathology from ”Ovidius” University of Constanta. PS-09-006 T-cell lymphoma in bone marrow: morphologic and immu- nophenotypic study H. Douik*, K. Tlili, G. Sahraoui, L. Charfi, I. Abbes, N. Boujel- bene, B. Hedhli, I. Nasri, O. Chekir, K. Mrad, R. Doghri *Salah Azaiz Institute of Cancer, Tunisia Background & objectives: T-cell lymphomas (TCL) account for 10-15% of all lymphoproliferative disorders. Although commonly present, bone marrow involvement by TCL can be diagnostically chal- lenging. Our aim was to establish a diagnostic approach to reliably identify bone marrow infiltration of TCL. Methods: Retrospective study of 58 cases of bone marrow involve- ment by TCL collected in the pathology department over a period of 20 years (January 2001-December 2021). We analysed the mor- phological particularities of bone marrow infiltration by TCL. Results: Our series included 41 males and 17 females with a median age of 45 years. The major subtype was TCL NOS in 58% followed by the angioimmunoblastic TCL in 18%. The anaplastic, the hepatosplenic and the NK subtype were diagnosed in 8% of cases for each one. The infiltration pattern was interstitial in 72%, nodular in 15%, focal para trabecular in 10% and intrasinusoidal in 3% of cases highlighted with immunochemistry markers. The infiltration percentage was less than 20% of cell population in 10 cases and more than 50% in 15 cases. Conclusion: Bone marrow involvement in TCL is prognostically important for appropriate management. Morphology with immu- nochemistry can be reliably used to diagnose the bone marrow infiltration and to rule out the differential diagnosis. PS-09-007 Prevalence of Epstein Barr virus in de novo diffuse large B-cell lymphoma NOS in Algeria N. Moulai*, M. Guermi, R. Bennoui, W. Ouahioune *Department of pathology and Cancer Research Laboratory, Blida University Hospital, Saad Dahleb University, Algeria Background & objectives: The prevalence of EBV in DLBCL accounts for <5-15% of DLBCL among Asian and Latin American patients and <5% among western patients. Our aim was to define the prevalence and clinicopathological features of EBV (+) DLBCL in Algeria. Methods: A total of 162 cases of de novo DLBCL treated with R-CHOP were evaluated from January 2015 to August 2019. LMP1 and EBNA2 were performed for latency. The presence of EBV determined by EBER-ISH assay with 20% of cut-off. Clinical and pathological data were analysed. Results: Of these 162 cases with DLBCL,13 (8%) showed EBV positivity. The median age of EBV(+)-DLBCL patients was 59, range from 22-87. 77% EBV(+)-DLBCL present in the nodal site . The ABC phenotype was found in 100% of our cases. 53.8% showed type III EBV latency. Clinically, EBV(+)-DLBCL pre- sented an advanced clinical stage (84.6%), a high IPI (46.2%), and a low rate of response to treatment and survival (69.2%). Our results showed a significant difference between the two groups EBV(+)-DLBCL and EBV(-)-DLBCL on the response to R-CHOP treatment (p=0.01) and survival rate between the two groups. Log Rank (Mantel-Cox) p=0.0001 Conclusion: The prevalence of EBV in DLBCL is estimated at 8% in our series, joining the Asian series. This is still considerable compared to Western countries. Survival was significantly associ- ated with EBV in our study. PS-09-008 The molecular spectrum of anaplastic large cell lymphoma (ALCL) - the wide next-generation sequencing profiling A. Szumera-Ciećkiewicz*, A. Dansonka-Mieszkowska, J. Poleszczuk, O. Kuczkiewicz-Siemion, K. Kurek, E. Paszkiewicz- Kozik, M. Prochorec-Sobieszek, A. Tysarowski, J. Walewski, G. Rymkiewicz *Narodowy Instytut Onkologii im. M. Sklodowskiej-Curie, Poland Background & objectives: ALK-negative anaplastic large cell lym- phoma (ALCL) ) is a malignant CD30-positive T cell neoplasm and clinically/molecularly three different subgroups have been outlined: DUSP22 -rearranged, TP63 -rearranged, and triple-negative cases (lack- ing DUSP22,TP63,ALK ) with 5-year overall survival 90%, 17%, and 42%, respectively. Methods: We investigated 26 ALCL cases: 17 ALK-negative and 9 ALK-positive (as a control group). The histopathological confirmation of the diagnosis (morphology and immunoprofile) with a consecutive 125-gene panel assay dedicated to lymphomas was performed. Samples and genes were clustered according to the Kendall rank correlation coefficient calculated on the per- centage of reads value. Results: The subgrouping of ALCL revealed: no(0) DUSP22 -rear- ranged, three(3) TP63 -rearranged, and sixteen(16) triple-negative cases. The prevalence of genes fusions (PGF) in the ALCL ALK- positive and ALK-negative groups included CCND1 and CCND3 (100%); the most frequently presented gene isoforms (PGI) in these two ALCL groups were BATF3 (70%) and ETV6 (60%). The profile of PGI in ALK-positive and triple-negative cases differed in LMO2, MUM1/IRF , MUC1 and were respectively 15%, <1%, 57% vs. 44%, S118