A case of adult T-cell leukaemia/lymphoma characterized by multiplex-fluorescence in situ hybridization, comparative genomic hybridization, fluorescence in situ hybridization and cytogenetics

Adult T-cell leukaemia/lymphoma (ATLL) is a neoplasm of mature helper (CD4) T lymphocytes. Little is known, however, about the chromosome aberrations associated with the pathogenesis of this malignancy. Using molecular cytogenetic techniques we, therefore, investigated a 44-year-old man who had a 7-year history of ATLL with cutaneous involvement mimicking primary cutaneous T-cell lymphoma. Conventional cytogenetics revealed gross chromosomal changes with chromosome numbers ranging from 71 to 82. There were structural abnormalities of chromosomes 7 and 9, partial deletions of chromosomes 1, 3, 5 and 6, and loss of chromosomes 2, 4, 9, 11-14, 21 and 22. Multiplex-fluorescence in situ hybridization (M-FISH) identified two derivative chromosomes, der(6)t(6;7)(q16;q21) and der(7)t(6;7)(q16;q21)ins(6;12)(q2?;?), and a deletion of chromosome 1p. Conventional FISH confirmed the M-FISH findings. Comparative genomic hybridization of the blood revealed gains of DNA copy number at 1q12-25, 6p24-25, 9p23, 16p13-q13, 17q11-21, 19p13 and 20q13 and loss at 11p15 while lymph nodes showed gains at 3p22-24, 3q27-29, 7q36 and 15q26 and losses at 2p24-25, 2q37, 10p14-15, 11p15, 13q33-34 and 16p13.3. No DNA copy number changes were seen in a skin lesion. These results show the extent of genetic abnormalities within this malignancy.