Application of interphase fluorescence in situ hybridization in the diagnosis of lymphoma

Abstract

To investigate the feasibility of interphase FISH in the routine clinicopathological practice and its values in the differential diagnosis of lymphomas. A total of 74 fresh tissue samples clinically suspicious of lymphoma were investigated by FISH using three probes including IgH/bcl-2, IgH/CCND1 and API2/MALT1, corresponding the translocation t(14;18), t(11;14) and t(11;18) respectively. The results of FISH were analyzed and compared with the histopathologic diagnosis. Histological evaluation eventually confirmed that there were 62 cases of lymphoma and 12 cases of reactive lymphoid processes. The translocations were detected in 7 cases in 62 cases of lymphoma: 3 demonstrated t(14;18) including 2 cases of follicular lymphomas and 1 nodular sclerosing Hodgkin lymphoma. Four cases had t(11;14) including mantle cell lymphoma (2 cases), follicular lymphoma (1 case) and small cell lymphoma (1 case). A lymphoid hyperplasia case showed detectable t(14;18). All 25 cases of DLBCL showed no evidence of t(14;18). Amplification or loss of regional genes was seen more often in malignant than in the benign cases. Interphase FISH offers useful ancillary technology that plays an important role in differential diagnosis and classification of lymphoma.