Detection of BCL-2 gene rearrangement in follicular lymphoma by polymerase chain reaction and chemiluminescence technique.

The incidence of follicular lymphoma in Saudi Arabia is very low compared to that in Western countries. We analyzed 22 diagnosed cases, based on conventional morphology examination and immunohistochemistry, to detect the Bcl-2 gene rearrangement by polymerase chain reaction (PCR). The DNA was extracted from formalin-fixed paraffin-embedded lymph node tissues by the standard xylene treatment and proteinase K digestion method. Rearrangement of the major breakpoint region was evident in 8 of the 22 cases (36%), determined by visualization of a discrete band hybridized with a chemiluminescence-labeled specific probe. Although the number of cases is small, we believe it denotes a normal detection rate for PCR analysis, using DNA isolated from fixed tissue. With the exception of follicular lymphoma, non-Hodgkin's lymphoma (NHL) analyzed included diffuse large cell lymphoma, lymphoblastic lymphoma, chronic lymphocytic leukemia, mucosa-associated lymphoid tissue and mantle zone lymphomas. No Bcl-2 gene rearrangement was detected in any of these cases. No evidence of Bcl-2 minor cluster sequence gene rearrangement was detected in any of the 38 NHL cases analyzed.