• Test Code:
    7450
  • Department:
    Cancer FISH
  • Test Synonyms:
    DLBCL FISHDLBL FISHB-Cell Lymphoma
  • CPT Code(s):
    88271x588275x588368x1 (FFPE)88369x4 (FFPE)
Background:

Diffuse Large B-Cell Lymphoma (DLBCL) is a lymphoid neoplasm, particularly involving large (microscopically) B cells.  This FISH panel is designed to detect the most common, and/or prognostically-significant abnormalities in DLBCL, and may aid in discrimination between DLBCL and other lymphomas (Swerdlow et al. 2008) as well as uncovering ‘double hit’ lymphomas (Aukema et al. 2011).  FISH studies are useful adjuncts to complete chromosome studies, particularly when following an abnormal clone, assessing relapse and progression, or when material is inadequate for chromosomal analysis.

The DLBCL FISH panel includes:

  1. IGH/BCL2 dual-fusion probe, to detect t(14;18) and disruption of BCL2 (18q21.33).
  2. MYC break-apart probe, to detect disruption of MYC (8q24).
  3. BCL6 break-apart probe, to detect disruption of BCL6 (3q27).
  4. IGH/MYC dual-fusion probe, to detect t(8;14).
  5. IRF4 break-apart probe, to detect disruption of IRF4 (6p25).

Note: Reflex testing may include IGH break-apart, IGK break-apart, and/or IGL break-apart when relevant.  Additional charges apply.

Note: Interphase FISH analysis is not intended to stand alone, but rather to provide supplemental information to routine cytogenetic studies.

Methodology:

Slides are prepared per standard protocols and 100-200 interphase cells are scored per probe.
*Please note: it is our laboratory policy to analyze at least one metaphase cell from every hybridization if possible, including both normal and abnormal cells if both exist.

Specimen Requirements:

The DLBCL FISH Panel can be performed on the following specimen types.  After collection, keep at room temperature until shipping.  Contact Client Services at (855) 535-1522 for shipping kits and instructions.

  • Bone Marrow:  Shortly before aspiration add 0.2 cc of Sodium Heparin (1,000 units/ml) to tube of transport medium (please contact lab to arrange for transport medium to be sent).  Add at least 1 cc of bone marrow aspirate to the tube and suspend well.  Allow no clots to form.
  • Peripheral blood: May be used if bone marrow is inaspirable and blasts (.5%) are present.  Send in Sodium Heparin tube.
  • Bone core biopsy: May also provide cells in cases where marrow is severely packed.  Send in transport medium with Sodium Heparin.
  • Lymph node or tumor: Tumor specimens of at least 0.5 cm3 (up to 3 inches in diameter) are immediately collected with sterile methods into closable containers with sterile transport medium.* Needle biopsies will be accepted, but are often difficult to grow.  Deliver the specimen in transport medium to the laboratory within a day, if possible, with decreased success rates as specimens are delayed in transit.  Protect sample from temperature extremes during shipping.
  •  

    *Sterile Ringer’s solution, either lactated or non-lactated and sterile isotonic saline are alternatives, if no complete RPMI is available.  Contact Client Services for more information on media requirements.
    It is preferable to collect the specimen before initiation of chemotherapy in the patient.  Tumor samples should be selected from viable areas, with as little normal or necrotic material as possible. 
    Fluid samples (e.g., ascitic or pleural fluid) do not require culture medium for collection, but should be collected and transported aseptically. 
    Unacceptable specimens are acellular, necrotic specimens, septic specimens, specimens in fixative or frozen, or specimens collected more than one week previously. 

  • Formalin-fixed paraffin-embedded tumor block or FFPE slides:  Store at room temperature. Preferred slice thickness is 5 micrometer on +charged slides.  Please submit 6-12 slides.  Contact Client Services for more information

A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES.  Please include detailed clinical information. 

Test Performed (Days):

Mon - Sat

Turn Around Time:

5 – 10 days Contact Lab at 855-KDL-1LAB (535-1522). Time varies depending on number of tests performed per specimen

Shipment Sensitivity Requirements:

  • Keep specimen at room temperature during transit. 
  • Do not use the cold pack provided in the KDL shipping kit. 
  • Ship the specimen overnight express, using the FedEx priority overnight label provided. 
  • The specimen must arrive at the lab no more than 24 hours after collection.

References:

  1. Swerdlow et al. (Eds.): WHO Classification of Tumors of Haematopoietic and Lymphoid Tissues. IARC: Lyon 2008.
  2. Aukema et al. 2011. Double-hit B-cell lymphomas.  Blood 117(8), 2319-2331.

Additional Info: