Test Directory

MALT1, 18q21.31-q21.32

Translocation (11;18)(q21;q21) has been associated with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). Translocation (11;18) leads to the fusion of the apoptosis inhibitor-2 (API2) gene and the MALT lymphoma-associated translocation (MALT1) gene. However, it has been found that 18% of MALT lymphomas have t(14;18)(q32;q21) or a translocation involving the immunoglobulin heavy chain (IGH) and MALT1 gene. MALT lymphomas with t(11;18)(q21;q21) usually do not have additional genetic aberrations, which is in contrast to t(14;18)(q32;q21) cases. Aneuploidy is most often seen in the majority of t(14;18)(q32;q21) MALT lymphomas. FISH can detect this rearrangement in either interphase or metaphase cells.

Specimen: Formalin-Fixed Paraffin Embedded (FFPE) Tissue Block or 2 slides from FFPET block, cut at 4 micron thickness and mounted on charged lysine slides with accompanying H&E slide indicating the region(s) of interest (ROI), if the entire specimen is not tumor.

Specimens should have an ischemia time of < 1 hour and a formalin fixation time between 6 - 72 hours.

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.

• Specimen arriving without any form of patient identification (unlabeled)
• FFPET sections that are not properly attached to the slide
• FFPET sections with excessive cracks, splits or deterioration that would inhibit analysis
• Broken FFPET slides

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 MALT1 Breakapart, Tissue
• MALT1 BA
• MALT1
• Mucosa-Associated Lymphoid Tissue Lymphoma Translocation Protein 1