Objectives  To explore the cytogenetic characteristics of diffuse large B cell lymphoma(DLBCL) with bone marrow involvement(BMI).

  Methods  The caryotype of 55 DLBCL patients with BMI were analysed using conventional cytogenetic(CC), and the gene of IgH.Rb1, D13S25, P53, ATM, Bcl-2 / IgH, Bcl-6 and c-MYC of 18 patients were detected by fluorescence in situ hybridization (FISH).The prognostic value of cytogenetic and clinical characteristics were analysed.

  Results  Chromosome aberrations(CA) were detected in 34 of 55 petionts(61.8%) by CC, including complex aberrations in 21 cases and highly complex aberrations in 15 cases.Eighteen cases were detected with FISH and 8 cases were positive for the Bcl-2 amplication by FISH.2 cases for the t(14:18) aberration, 7 cases for IgH, 5 for Bcl-6 amplication.5 for P53 deletion, 3 for D13S25 deletion.2 for Rb-1 deletion and 4 cases for c-MYC amplication.Three cases with normal caryotypes by CC had abnormal cytogenetics by FISH.The statistical analysis showed that the sensibility and specificity of FISH is obviously superior to CC(P = 0.023).The clinical characteristics of age < 60, serum albuminal < 35 g/L, more than two extranodal site involvement, moderate and severe BMl, hepotomegaly and / or splenomegaly were more prevalent in patients with abnormal cytogenetics than in those with normal ones.Univariate analysis showed that hepotomegaly, splenomegaly, serum albuminal < 35 g/L, more than two extranodal site involvement, moderate and severe BMI, abnormal cytogenetics and CA of chromosomes 1.2, 3, 6, 13, 17 and 18 were associated with shorter OS.Multiple analysis showed that splenomegaly, moderate and severe BMI and CA of chromosome 17 were independent prognostic factors of DLBCL with BMI.

  Conclusion  The detection rate of DLBL with BMI was high and every chromosome can be involved.The sensibility and specificity of FISH is obviously superior to CC.Splenomegaly, moderate and severe BMl and CA of chromosome 17 were independent prognostic factors of DLBCL with BMI.