RESUMO
<p><b>OBJECTIVE</b>To evaluate the role of cytogenetic study and interphase FISH analysis in differential diagnosis of patients with clinical and/or cytological diagnosis as lymphoma or "suspicious for lymphoma".</p><p><b>METHODS</b>Routine histology, immunohistochemistry, cytogenetics and interphase FISH studies were used to assess 223 cases with superficial lymph nodes of not less than 1. 5 cm in diameter. The probe used in the interphase FISH assays is the Vysis' LSI IGH Dual Color, Break Apart Rearrangement Probe.</p><p><b>RESULTS</b>Based on these studies, forty-four patients were diagnosed as Hodgkin's lymphomas ( HL) , 162 as Non-Hodgkin's lymphomas ( NHL) , 11 with benign diseases and 4 as other malignancies, while the remaining 2 cases were discarded due to tissue necrosis. Using interphase FISH, abnormalities of immunoglobulin heavy chain gene (IGH) were detected in 6/44 (13.6%) and 83/162 (51.2%) in the HIL and NHL cases, respectively, while none was observed in 11 cases with a benign disease (P <0. 001). Combining cytogenetics and FISH studies, the detection rates for HL and NHL cases then increased to 15.9% and 77. 8%, respectively, otherwise, 3 of whom could not have made definite diagnosis.</p><p><b>CONCLUSION</b>Interphase FISH assay is a rapid and sensitive tool for detecting IGH abnormalities. Both cytogenetics and interphase FISH analyses may play a significant role in diagnosis of lymphomas.</p>