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BCL2 (14,18) by Fluorescence in situ Hybridization

F BCL2

Test Synonym:

Follicular lymphoma, chronic lymphocytic leukemias

CPT Code:

88367-2H x2 – Morphometric analysis

Turnaround Time:

3 days

Methodology:

Fluorescence in situ hybridization (FISH)

Specimen Requirements:

  • 5.0mL (min. 3.0 mL) peripheral blood in sodium heparin preferred, EDTA accepted
  • 3.0mL (min 1.0mL) bone marrow in sodium heparin preferred, EDTA accepted
  • 5mm3 fresh tissue in MPLN RPMI media
  • 3.0mL (min 2.0mL) FNA in MPLN RPMI  media

    • Causes for Rejection:

    Clotted specimen; specimen exposed to extreme temperature; anticoagulant toxic to cells; insufficient number of cells

    Specimen Stability:

  • Peripheral blood and bone marrow - 72 hours at 18-25°C
  • Fresh tissue or FNA - 72 hoursat 2°-8°C

    • Storage and Handling:

  • Whole blood and bone marrow ship ambient
  • Fresh tissue or FNA ship in a styrofoam container with an ice pack (do not allow ice pack to directly contact sample)

    • Reference Range:

    BCL-2 translocation not detected

    Indication:

    The t(14;18)(q32;q21) leads to the juxtaposition of the immunoglobulin heavy chain (IGH) locus and the B-cell lymphoma/leukemia (BCL2) locus.  Translocation of the IGH transcription enhancer next to the BCL2 gene results in increased transcription of the BCL2 oncogene.  The enhanced expression of BCL2 interferes with the normal apoptosis of B-lymphocytes.  Up to 90% of follicular lymphomas show the t(14;18) as the primary cytogenetic abnormality.  Up to 40% of chronic lymphocytic leukemias (CLL) also carry this translocation.  In general, B-cell neoplasms that are positive for the BCL2 translocation are associated with a poor prognosis.  FISH can detect this rearrangement in either interphase or metaphase cells.

    References:

    1. Crisan et al. (1996). BCL-2 gene rearrangements in lymphoid malignancies. Clin Lab Med 16(1):23
    2. Aster (2002). Detection of BCL2 rearrangements in follicular lymphoma. Am J Pathol 160(3):759
    3. Montoto et al. (2003). Incidence and clinical significance of bcl-2/IgH rearrangements in follicular lymphoma. Leuk Lymphoma 44(1)