Test Directory

IRF4, 6p25

The updated (2016) revision of the World Health Organization (WHO) classification of tumors of lymphoid neoplasms considers the large B-cell lymphoma with interferon regulatory factor 4 or multiple myeloma oncogene-1 (IRF4) rearrangement as a new provisional entity. Chromosomal translocations involving the IRF4 gene and the immunoglobulin heavy chain (IGH), immunoglobulin lambda locus (IGL) and immunoglobulin kappa locus (IGK) result in dysregulation of IRF4 expression. Other translocation partners may occur. Since t(6;14)(p25;q32) is cytogenetically cryptic, FISH is a valuable tool in detecting this recurrent aberration. IG/IRF4 positive lymphomas normally lack t(14;18), which is observed in about 85% of adult patients with follicular lymphoma and are commonly associated with young age and a good course. IRF4 rearrangements have also been identified in peripheral T-cell lymphomas (PTCL). PTCL are defined as a diverse group of aggressive lymphomas of mature-stage T-cells accounting for about 10% of non-Hodgkin lymphomas. Recent data suggests that IRF4 translocations detected by FISH have a predictive value for primary cutaneous CD30(+) anaplastic large cell lymphoma.

Specimen Types: Leukemic Blood or Bone Marrow

Preferred Collection Container: Green Top (Sodium Heparin)

Alternate Collection Container: Lavendar Top (EDTA)

Desired Specimen Volume: 3 - 5 mL

Minimum Acceptable Volume: 1 mL

• Lithium heparin is not acceptable.
• Specimens must be collected in a sterile collection container.

Each specimen must be accompanied by a requisition form, script, electronic order or physician note. Each order must indicate the reason for testing (diagnosis).

• Transport to the laboratory at room temperature.
• Store specimen as whole blood, in original tube, at room temperature and deliver to lab within 24 hours.
• If specimen cannot be delivered within 24 hours, store in refrigerator. Do not freeze specimen.
• Specimens collected on the weekends must be refrigerated upon arrival at HNL Lab Medicine.

• Specimen frozen
• Specimen arriving without any form of patient identification (unlabeled)
• Specimen with attached needles
• Specimen arriving with broken or leaking collection tube
• Unfixed specimen treated with fixative

In a normal cell, the expected signal pattern is two fusion signals. In an abnormal cell containing a rearrangement, the expected signal pattern is one red signal, one green signal, and one fusion signal.

• FISH IRF4 Breakapart, Heme
• IRF4 BA
• IRF4
• Interferon Regulatory Factor 4
• Multiple Myeloma Oncogene-1