OBJECTIVETo use array-based comparative genomic hybridization (aCGH) technology to study the molecular cytogenetic abnormalities of anaplastic large cell lymphoma (ALCL) at genome level.

METHODSALK protein expression and molecular genetic abnormalities were detected by immunohistochemistry and fluorescence in situ hybridization, respectively, in 25 cases of ALCL. Any chromosomal gains/losses were detected by aCGH and correlated with ALK status.

RESULTSaCGH showed that chromosomal alterations in all 25 ALCL cases, and the frequency of chromosomal gains was higher than that of the losses. Chromosomal gains at 5p13.2, 3q21.1, 2q21.3, 3p25.1, 14q32.33, and 17q21.2 regions were detected in more than 50% of the ALCL cases; gains at 4q27, 6p22.1, 20p11.21, 2q22.3, 4q35.1, 1p36.22, 8p23.1, 8p12, 11q14.1, 12q13.13, and 19p13.3 regions were detected in 30%-50% of the ALCL cases; chromosomal losses at 3q26.1 and 3q26.31 regions were detected in 36.0% (9/25) and 24.0% (6/25) of the ALCL cases, respectively. Chromosomal gains at 2q21.3, 6p22.1 and 3p25.1 regions showed significant differences between ALK (+) and ALK (-) ALCL groups (P < 0.05).

CONCLUSIONSaCGH demonstrates complex molecular genetic variations in all ALCL cases. Gains at 2q21.3, 6p22.1 and 3p25.1 regions are significantly different between ALK (+) and ALK (-) ALCL groups, suggesting that the pathogenesis of ALK (+) and ALK (-) ALCL may involve different signaling pathway.