Novel genomic imbalances in B-cell splenic marginal zone lymphomas revealed by comparative genomic hybridization and cytogenetics

Splenic marginal zone lymphoma (SMZL) has recently been recognized in the W orld Health Organization classification of hematological diseases as distin ct type of non-Hodgkin's lymphoma. In contrast to the well-established chro mosomal changes associated with Other B-cell non-Hodgkin's lymphoma, few ge netic alterations have been found associated with SMZL, The aim of our stud y was to analyze by comparative genomic hybridization (CGH) the chromosomal imbalances in 29 patients with SMZL and to correlate these findings with c linical and biological characteristics and patient outcome. In 21 cases, cy togenetic studies were simultaneously performed. Most of the patients (83%) displayed genomic imbalances, A total of 111 DNA copy number changes were detected with a median of four abnormalities per case (range, 1 to 12). Gai ns (n = 92) were more frequent than losses (n = 16), while three high-level amplifications (3q26-q29, 5p11-p15, and 17q22-q25) were observed. The most frequent gains involved 3q (31%), 59 (28%), 12q and 20q (24% each), 9q (21 %), and 4q (17%). Losses were observed in 7q (14%) and 17p (10%). SMZL pati ents with genetic losses had a shorter survival than the remaining SMZL pat ients (P < 0.5). In summary, chromosomal imbalances in regions 3q, 4q, 5q, 7q, 9q, 12q, and 20q have been detected by CGH in SMZL. Patients with SMZL displaying genetic losses by CGH had a short survival.