Use of test
Gene fusions involving the BCL6 gene at 3q27 can occur in B-cell non-Hodgkin lymphomas (B-NHL), particularly diffuse large B-cell lymphoma (DLBCL). BCL6 gene fusions are also seen in patients with follicular lymphoma or marginal zone lymphoma. These gene fusions have diagnostic and prognostic implications.
Presence of a BCL6 gene fusion can be useful in diagnosing and sub-classifying B-NHL. It can also indicate prognosis in B-cell lymphoma with features intermediate between DLBCL and Burkitt lymphoma, in association with BCL2 and MYC gene fusions (see Multiple hit lymphoma FISH).
This is an assay for non-heritable mutations. It does not raise issues of ethics or consent that are different from most other investigations ordered in the routine care of a patient.
Fluorescent in situ hybridisation (FISH) analysis, using probes to identify fusion of BCL6 with a partner gene. The breakpoints involved in these fusions can be variable, and in some cases certain variants will not be detected by the probe. If performed on FFPE tissue, some cells in the section may be sliced by the process, and only contain some regions of interest. Sections may contain bony, fatty or necrotic material, which may interfere with processing and/or analysis. Dense tissue also makes identification of individual cells difficult. The accuracy of the results is dependent on the correct identification of tumour on the sections provided, and the assumption that positive results will be identified by a large proportion of cells within the tumour having a rearrangement.
Requesting the test
This test is usually requested by a haematologist or oncologist. This test is often requested as part of the Multiple hit lymphoma FISH panel.
0.5 mL bone marrow in transport media, or formalin-fixed, paraffin embedded tissue (FFPE).
To help ensure the quality of the test, a genetic test should be done with a dedicated sample whenever possible i.e. a sample collected specifically for that test rather than a sample that is used for multiple tests.
We recommend that the patient or another adult check the labelling of request forms and sample tubes.
If requesting on FFPE, please label each slide with patient and block identifiers plus number them sequentially 1-15. Stain slides 1 and 15 with H&E and leave slides 2-14 unstained.
Up to 4 weeks.
This test has a Medicare rebate which, subject to the requirements of the Medicare descriptor being met, may cover all or part of the cost. If the patient is not eligible for rebated testing, please contact your local Sonic pathology practice for pricing.
The Medicare details, including descriptor and schedule fee, are listed under MBS item 73364.