FISH for MALT 1 (18q21)

Test Mnemonic


CPT Codes

  • 88377 - QTY (1)


  • FISH for assessment of Extranodal Marginal Zone B
  • Fluorescence In Situ Hybridization for MALT 1 (18q21)


  • LSI 18q21.3

Performing Laboratory

Cleveland Clinic Laboratories

Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
2 slidesSlide (s), unstainedClean container AmbientOne formalin-fixed, paraffin embedded block containing representative tissue OR unstained 4 μm tissue sections on electrostatically charged slides containing representative tumor. Tissue must be fixed in formalin NOT B5 or PREFER fixative


Environmental Condition Description
AmbientSample is formalin fixed and must not be fixed in Prefer or B5.

Days Performed

5 days per week

Turnaround Time

3 - 5 days


Name Description
Fluorescent In-Situ Hybridization (FISH) 

Clinical Info

Interphase FISH analysis utilizing a dual color, break-apart probes for the MALT1 gene at 18q21.3. Rearrangements of the MALT1 gene are observed in marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue. The translocation partner gene cannot be identified in this assay. If no cells are available for analysis, no analysis charges will be incurred.