Background: C-MYC, BCL2 and BCL6 genes are the most commonly involved oncogenes detected in B-non-Hodgkin's lymphomas (B-NHLs). Histopathology is the best method used to diagnose B-NHLs. However, the cytological analysis of bone marrow smears and imprints could provide a chance for a precise diagnosis of these disorders. Objective: This study aimed to evaluate bone marrow findings as an integral part of the staging workup in B-NHLs and to study possible relationship to C-MYC, BCL-2, and BCL-6 gene abnormalities. Patients and methods: This study was conducted as a cross-sectional study that included 51 adult B-NHL patients. Each patient underwent careful history assessment, clinical examination, laboratory tests (e.g. complete blood count, BM smears, BM biopsy, lymph node biopsy, immunophenotyping on bone marrow aspirates by flowcytometry and interphase FISH dual color break-apart probes of C-MYC, BCL2 and BCL6 on bone marrow aspirates). Results: Results of lymph node biopsy histopathological examination revealed that, FL, DLBCL, and MCL were diagnosed in 43.1%, 39.2% and 17.6% of them respectively. Among 51 B-NHL cases, there were 35.29%, 31.37% and 23.53% positive cases for C-MYC, BCL2 and BCL6 respectively. Concurrent genetic aberrations showed double expression. of
C-MYC and BCL2 constituted 17.6% and triple expression of C-MYC, BCL2 and BCL6 that constituted 7.8% of the cases. However, the FISH positive cases were more frequent in MCL than FL and DLBCL. The BCL2 was more significantly associated with FL subtype and BCL6 with DLBCL subtype. Conclusion: C-MYC, BCL2 and BCL6 gene aberrations frequently occurred in B-NHLs and could be considered as independent prognostic factors that carry different impacts on BM marrow biopsy finding and BM infiltration which affect clinical outcome of patients.