A B-cell lymphoma may exhibit multiple gene rearrangements involving the genes MYC and BCL2 or MYC and BCL6 (double hit), or MYC and BCL2 and BCL6 (triple hit). These rearrangements have prognostic implications.
Double and triple hit lymphomas have a poor prognosis.
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 detect gene fusions/rearrangements involving the MYC, BCL2 and BCL6 genes. If performed on FFPE tissue, some cells in the section may be sliced by the process, and only contain some of the 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.
0.5 mL bone marrow in transport media or 10 mL blood in lithium heparin if clinically appropriate; 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 with H&E and leave slides 2-14 unstained.
Up to 4 weeks.
If more information is required, the requesting clinician can call our laboratory on (07) 3377 8573.
An MBS rebate is available for DLBCL or high-grade B-cell lymphoma, if criteria are met (item number 73364).