MYC gene rearrangements detected by interphase fluorescence in situ hybridization in diffuse large B-cell lymphomas.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma, including approximately 30-40% of all B-cell non-Hodgkin lymphomas (B-NHL). Chromosomal translocations are the hallmark of genetic aberrations in B-lymphoma and are often associated with a specific subtype of B-NHL. MYC gene dysregulation due to chromosomal translocations is characteristic for the most cases of Burkitt's lymphoma. Objective. The goal of this study was to improve the diagnostic accuracy of DLBCL. Identification of chromosome 8 and 14 abnormalities including the translocation of MYC gene t(8; 14)(q24; q32) in substrate cells of lymph nodes was applied using the method of tri-color interphase fluorescence in situ hybridization (I-FISH). Materials and methods. Lymph node biopsy specimens of 17 patients with diffuse large B-cell lymphoma and three patients with Burkitt's lymphoma (including one participant of liquidation of consequences of the catastrophe at the Chornobyl NPP) were studied. The age of patients ranged from 10 to 66 years old (41.3 ± 3.7 average). Biopsy specimens fixed in paraffin. I-FISH-analysis was performed using the commercial test Vysis IGH/MYC, CEP 8 tri-color, dual fusion translocation probe (Abbott Molecular, USA). Results and conclusions. MYC gene and immunoglobulin heavy chain (IGH) gene translocations were found in four out of twenty persons. Consequently the I-FISH method allows identification of of MYC and IGH gene rearrangements in tissue cells substrate of lymphoma fixed in paraffin. Using this method the molecular-cytogenetic abnormalities were found in eight of twenty patients with B-cell lymphoma providing verification of the lymphoma diagnosis, prediction of their clinical course and advance in management i.e increase the effectiveness of therapy, in refractory lymphoma cases among others.