Recent genetic and molecular studies have shown that a subset of IMT is characterized by the expression of altered anaplastic lymphoma kinase (ALK) protein mostly resulting from rearrangements of the ALK gene such as TPM3-ALK, TPM4-ALK and CLTC-ALK fusion genes.
As 2;17 translocation resulting in the fusion of clathrin heavy chain (CLTC) gene with ALK was previously reported in inflammatory myofibroblastic tumor, we performed reverse transcriptase-polymerase chain reaction and demonstrated that the lymphoma cells contained CLTC-ALK fusion transcript.
Although a similar CLTC-ALK aberration was previously identified in ALK-positive T-/null cell ALCL and inflammatory myofibroblastic tumor, its association with ALK-positive LBCL seems to be specific and intriguing.