Fluorescent in situ hybridization studies in multiple myeloma.

Conventional cytogenetic analysis and fluorescence in situ hybridization (FISH) results of bone marrow samples of 36 multiple myeloma (MM) patients at the time of diagnosis have been evaluated. Three probes for chromosome 13q (RB1, D13S319, D13S25), one for 14q32 (IgH) and one for 17p13 (p53) have been used for hybridization with fixed cells. Twenty patients (55.5%) had normal karyotypes, whereas eight (22.2%) had numerical or structural chromosomal abnormalities. We did not find metaphases for chromosome analysis in eight (22.2%) patients. Fluorescence in situ hybridization analyses revealed at least one or more abnormal results in 25 (69.5%) cases, whereas 11(30.5%) cases had no abnormal findings. 14q32 rearrangement was the most common finding in FISH analyses and has been detected in 21 cases (58.3%). 13q deletion and 17p deletion have been detected in 11 (30.5%) and 5 (13.9%) cases, respectively. Fluorescence in situ hybridization studies including 14q32 and 17p13 chromosome regions may yield quite significant results during clinical follow-up of MM.