FISH, HES/Leukemia, 4q12 Rearrangement, TC

Test Code

12646

CPT Codes
88271, 88275<br>Restricted Client Code - Tech Only

Preferred Specimen

3 mL bone marrow or 5 mL whole blood collected in sodium heparin (green-top) tube

Minimum Volume

1 mL bone marrow • 3 mL whole blood

Other Acceptable Specimens

Bone marrow or whole blood collected in: sodium heparin (royal blue-top) tube, or sodium heparin lead-free (tan-top) tube • 5 x5mm fresh tumor tissue collected in transport medium • Formalin-fixed paraffin-embedded tissue block

Instructions

Clinical history/reason for referral is required with test order. Prior therapy and transplant history should be provided with test order.

Bone marrow: 1-3 mL in transport medium (preferred) or sodium heparin tube.
3-5 mL whole blood in sodium heparin tubes. Green, dark/ royal blue or tan top tubes are acceptable containers for this test.
Formalin-fixed, paraffin-embedded block and fresh tumor tissue samples are also acceptable.

Specimen viability decreases during transit. Send specimen to testing lab for viability determination. Do not freeze. Do not reject.

Transport Temperature

Room temperature

Specimen Stability

See Instructions

Methodology
Fluorescence in situ Hybridization

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Daily; Report available: 5 days

Clinical Significance

100-200 interphase nuclei are examined microscopically for the rearrangements of 4q12.

FIP1L1-PDGFRa fusion (rearrangement of 4q12; interstitial deletion of CHIC2 region) is observed in diverse eosinophilia-associated hematologic disorders. The cases with FIP1L1-PDGFRa fusion show an excellent response to the tyrosine kinase inhibitor imatinib mesylate (Metzgeroth et al., 2007).

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.