In non-follicular lymphoproliferative disorders, IGH/BCL2-fusion is not restricted to chronic lymphocytic leukaemia.
The translocation t(14;18) and its t(2;18) and t(18,22) variants, which involve the BCL2 genetic hallmark for follicular lymphoma (FL), have been reported in several cases of chronic B-cell lymphoproliferative disease (CLPD) and frequently in chronic lymphocytic leukaemia (CLL). We describe here the clinical, morphological, immunological, cytogenetic and molecular findings from 37 cases of t(14;18)-positive CLPD, identified from our series of non-FL B-cell neoplasms (n=993) that were routinely analysed in peripheral blood by conventional cytogenetics analyses. The FL diagnosis was excluded by morphology and immunology (the samples were CD10 negative in all cases). The BCL2 translocations were observed in 22 CLL cases, including 7 monoclonal B-cell lymphocytosis (MBL) cases re-classified according to the new International Workshop on CLL criteria, six small lymphocytic lymphoma (SLL) cases, 1 splenic marginal zone lymphoma (SMZL) case and eight cases of unclassifiable CLPD with overlapping CLL/MZL features. In the CLL cases, the IGH/BCL2 fusion was remarkably associated with trisomy 12 (13/22) and mutated IGHV status (20/21) and did not affect the outcome. Moreover, most of these CLLs harboured a low mutation load of BCL6 gene and unmutated FAS (CD95) loci, which points to a post-germinal-centre cellular origin.
Service d'Hématologie Biologique, UMR5239 Pathologies des cellules lymphoïdes, Université Claude Bernard, Lyon, France.
Lucile
L
Baseggio
Marie-Odile
MO
Geay
Sophie
S
Gazzo
Françoise
F
Berger
Alexandra
A
Traverse-Glehen
Martine
M
Ffrench
Sandrine
S
Hayette
Evelyne
E
Callet-Bauchu
Aurélie
A
Verney
Dominique
D
Morel
Laurent
L
Jallades
Jean-Pierre
JP
Magaud
Gilles
G
Salles
Pascale
P
Felman
D002881:Chromosomes, Human, Pair 12 / Q000235:genetics; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics; D019254:Genes, bcl-2 / Q000235:genetics*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D016130:Immunophenotyping; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000473:pathology / Q000628:therapy; D008218:Lymphocytosis / Q000235:genetics / Q000473:pathology / Q000628:therapy; D008232:Lymphoproliferative Disorders / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D050596:Oncogene Fusion; D014178:Translocation, Genetic; D016896:Treatment Outcome; D014314:Trisomy
D007143:Immunoglobulin Heavy Chains