OVERVIEW
Large B-cell lymphoma (LBCL) with IRF4 rearrangement is a rare subtype that accounts for 0.05% of diffuse LBCLs. The patient age range at presentation is 4-79 years, but occurrence is significantly more frequent in children and young adults with a median age at presentation of 12 years. It is characterized by strong expression of IRF4/MUM1 resulting from a rearrangement of the IRF4 gene with an IG locus. The main sites of involvement include the head and neck, Waldeyer ring, and the gastrointestinal tract. Prognosis for LBCL with IRF4 rearrangement is generally good with patients showing a favourable response to treatment.
TEST REQUIREMENTS
- Completed CGL Lymphoid Testing requisition form
- FFPE Tumour specimen (see Specimen Guidelines, Cytogenetics FISH FFPE test type)
- An H&E stained slide with the tumour region circled, and the estimated % tumour content written in the Tumour Content field of the requisition. NOTE: A minimum of 10% tumour and at least 200 nuclei is required.
- Specimen block and/or at least one unstained slide for each probe requested.
- See our FFPE Guidelines for additional details.
RESULTS REPORTING
Specimens are reported as Positive for a rearrangement, Negative for a rearrangement.
TURN-AROUND TIME
Results are reported within fourteen days from receipt of specimen and completed requisition form.
METHOD
FISH analysis is performed on the provided specimen using the tri-colour, break-apart probe (Cytocell) for IRF4/DUSP22 (6p25.3) and centromere 6.
