Translocations involving DUSP22-IRF4 or TP63 have a high specificity for cutaneous anaplastic large cell lymphoma. This FISH test identifies rearrangements involving these loci.
IRF4-DUSP22 rearrangements are identified in up to 30% of ALK negative anaplastic large cell lymphomas. TP63 rearrangements are identified in up to 8% of ALK negative anaplastic large cell lymphomas.
Presence of the IRF4-DUSP22 rearrangement is a positive prognostic sign, and a TP63 rearrangement is a negative prognostic sign.
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 rearrangements involving IRF4-DUSP22 and TP63. 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 5-10 mL blood in lithium heparin; 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 5 business days from receipt of specimen.
If more information is required, the requesting clinician can call our laboratory on (07) 3377 8573.
An MBS rebate is available if criteria are met (item number 73368).