Detection of t(14;18)(q32;q21) in B-cell chronic lymphocytic leukemia.
ABSTRACT Cytomorphologic testing and multiparameter flow cytometry are the mainstays in diagnosing B-cell chronic lymphocytic leukemia, whereas fluorescence in situ hybridization that targets the translocation t(14;18)(q32;q21) often is used to identify follicular lymphoma. Therapy is highly diverse between both diseases. We describe a case with cytomorphologically and immunologically proven B-cell chronic lymphocytic leukemia in which t(14;18)(q32;q21) was found.
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- "The t(14;18)(q32; q21), involving the immunoglobulin heavy chain (IGH@) locus and the B-cell CLL/lymphoma 2 (BCL2) gene, is characteristic of follicular lymphomas and is found in ~90% of cases . It is unusual in CLL and is found in, at most, 1% to 2% of cases        . The prognostic significance of t(14;18) in CLL is not clear. "
ABSTRACT: The t(14;18)(q32;q21) is a cytogenetic hallmark of follicular lymphoma and also occurs in approximately 20% of diffuse large B-cell lymphomas of follicle center cell origin. Relatively few cases of chronic lymphocytic leukemia/small lymphocytic lymphoma with t(14;18) have been reported previously. We report the clinicopathologic, cytogenetic, and molecular genetic features of 12 patients with chronic lymphocytic leukemia associated with t(14;18). There were 9 men and 3 women, with a median age of 51 years at diagnosis. To date, 11 patients have required chemotherapy, 6 before coming to our institution. At last follow-up, 5 patients have died of disease. Karyotypic analysis showed that 10 cases had t(14;18) in the stemline and 2 cases in the sideline; t(14;18) was the sole abnormality in the stemline in 2 cases. In 11 cases, other abnormalities were identified in the stemline or sidelines, most commonly trisomy 12 in 6 cases. Trisomy 12 was associated with atypical morphology and immunophenotype. Of 8 cases tested, 7 showed somatically mutated immunoglobulin heavy chain variable region genes. We conclude that the t(14;18) in chronic lymphocytic leukemia is associated with relatively young age at diagnosis, mutated immunoglobulin heavy chain variable region genes, and a clinical course that usually requires chemotherapy. The cytogenetic findings, in particular, t(14;18) in the stemline in 10 cases and as the sole karyotypic abnormality in 2 cases, suggest that t(14;18) is an early pathogenetic event in this small subset of chronic lymphocytic leukemia cases.Human pathology 10/2012; 44(4). DOI:10.1016/j.humpath.2012.07.005 · 2.81 Impact Factor
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ABSTRACT: In CLL data from chromosome banding analysis (CBA) have been scarce due to the low proliferative activity of CLL cells in vitro. We improved the cultivation technique using an immunostimulatory CpG-oligonucleotide DSP30 and IL-2. A total of 506 CLL samples were analysed with CBA and interphase FISH using probes for the detection of trisomy 12, IgH rearrangements and deletions of 6q21, 11q22.3 (ATM), 13q14 (D13S25 and D13S319) and 17p13 (TP53). A total of 500 of 506 (98.8%) cases were successfully stimulated for metaphase generation and are subject to this study. Aberrations were detected in 415 of 500 (83.0%) cases by CBA and in 392 of 500 (78.4%) cases by FISH. CBA detected 832 abnormalities and FISH only 502. Therefore, CBA offers important information in addition to FISH. (1) CLL is characterized mainly by genomic imbalances and reciprocal translocations are rare. (2) A subgroup with complex aberrant karyotype (16.4%) is identified which is associated with an unmutated IgV(H) status and CD38 expression (P=0.034 and 0.02, respectively). (3) Additional abnormalities are detectable providing new biological insights into different CLL subclasses revealing a much more heterogeneous pattern of cytogenetic abnormalities as assumed so far based on FISH data only. Therefore, prospective clinical trials should evaluate the prognostic impact of newly available CBA data.Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 01/2008; 21(12):2442-51. DOI:10.1038/sj.leu.2404935 · 9.38 Impact Factor
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ABSTRACT: A major conclusion drawn from the accumulated cytogenetic data on solid tumors and some hematologic malignancies is that tumors progress by the acquisition of chromosomal changes, as reflected by more aggressive tumors containing a larger number of chromosomal abnormalities. An additional observation is that some chromosomal changes appear early in the disease progression, and some others appear late. On the basis of this information, a model for karyotypic evolution in chronic lymphocytic leukemia (CLL) is presented. The Mitelman Database of Chromosomes in Cancer was searched, and 1749 abnormal karyotypes were assessed. The main clones were analyzed, and chromosomal gains and losses were used to design a model of genetic acquisition based on the calculation of a variable called time to occurrence (TO). Our comprehensive study of genetic abnormalities in a large number of CLL karyotypes revealed that most CLL has 2 chromosomal aberrations at diagnosis. Moreover, the temporal analysis suggests that trisomy 12 is an early event in the biological evolution of CLL. These results highlight the possibility of targeted therapies affecting the genes located on this chromosome (cyclin D, cyclin D2, cyclin-dependent kinase 2, and cyclin-dependent kinase 4).Clinical lymphoma, myeloma & leukemia 08/2013; 13(4):467-76. DOI:10.1016/j.clml.2013.05.003 · 2.02 Impact Factor