FISH – AML/MDS Panel

Fluorescence In Situ Hybridization – AML/MDS Panel

Test Overview

CPT Code(s)

88237-52, 88271×3, 88275, 88291

Methodology

Culture/Hybridization/Microscopy/Interpretation

Specimen Requirements

Bone Marrow and/or Leukemia Blood

Container: Sodium Heparin (green top tube)

Optimal Quantity: 2-3 ml

Minimum Quantity: 1-2 ml

Storage: Room Temperature

Stability at Room Temperature: 8 hours, then refrigerate

Transportation: Avoid freezing or heating over 35oC

Turnaround Time

Final report in 5 days for 90% of cases

Test Details

Clinical Significance

Fluorescence in situ hybridization (FISH) is a sensitive method to detect smaller genomic changes associated with various hematological malignancies and solid tumors.  There are several advantages with FISH technology over routine chromosome analysis and such advantages include the ability of FISH technology to detect genomic abnormalities in non-viable and non-dividing tissues, rapid turnaround time, and increased resolution.  However, FISH technology is complementary to routine chromosome analysis and cannot substitute routine chromosome analysis for diagnosis of cancer.

Clinical Background

Acute Myelogenous Leukemia/Myelodysplastic syndrome is a group of heterogeneous hematologic conditions with characteristic chromosome abnormalities leading to specific gene rearrangements.  About half of the patients with AML/MDS may show chromosome abnormalities which can be classified as primary and secondary or treatment related abnormalities.  The chromosome abnormalities are known to correlate with prognosis and response to treatment.  Although majority of such abnormalities can be detected on routine chromosome analysis, interphase FISH analysis due to its high sensitivity can detect low-level clones thus identifying prognostically and therapeutically important genetic abnormalities.

Methods

The samples are usually cultured for 24-hours before hybridizing with the probes.  After hybridization and post-hybridization washes, the slides are analyzed under a fluorescence microscope equipped with epifluorescence and appropriate filter sets.  Analysis and scoring is carried out by two certified technologists in a blinded fashion.  Results are reviewed by both the laboratory manager and the director. The AML/MDS FISH panel includes the following probes.

5q deletion / monosomy 5TAS2R1 / EGR1Cytocell (cat # LPH024)
7q deletion / monosomy 7RELN / TESCytocell (cat # LPH025)
t(8;21)ETO / AML1 (RUNX1/RUNX1T1)Cytocell (cat # LPH026)
11q rearrangementMLLCytocell (cat # LPH013)
t(15;17)PML / RARACytocell (cat # LPH023)
inv(16)MYH11 / CBFBCytocell (cat # LPH022)
17p deletionp53Cytocell (cat # LPH017)
20q deletion / monosomy 20MYBL2 / PTPRTCytocell (cat # LPH020)

Interpretation of Results

The morphologic interpretation and correlation of results on all cases is performed by a board-certified doctoral level scientist (laboratory director). The final report has a narrative description of results.  If abnormalities are present, they are explained in a paragraph which helps to clarify and correlate chromosomal findings with phenotype. References are included in the report to help the referring physician with interpretation, which include books or journals that contain appropriate information. Recommendations are made as to any additional testing, if necessary.