Fluorescence In Situ Hybridization – ALL Panel

Test Overview

CPT Code(s)

88237-52, 88271×3, 88275, 88291



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

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 lymphoblastic/lymphocytic leukemia (ALL) is the most common hematological malignancy seen in children.  A large number of specific chromosome abnormalities and/or gene rearrangements are seen in patients with ALL with the incidence of such abnormalities ranging from 65-85% for adults and 60-70% for children.  Detection of these abnormalities are vital in stratification of patients into different treatment groups and it is now mandatory to carry out chromosome and FISH studies, especially in children, for enrollment into Children’s Oncology Group (COG) treatment protocols. 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.


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 ALL FISH panel includes the following probes.

8q rearrangementcMYCCytocell (cat # LPH010)
9p deletionp16 / D9Z3Cytocell (cat # LPH009)
hyperdiploidy – chr. 4FIP1L1 / CHIC2 / PDGFRACytocell (cat # LPH032)
hyperdiploidy – chrs. 10 & 17D10Z1 / D17Z1Cytocell (cat # LPE010G/LPE017R)
t(12;21)ETV6 / AML1Cytocell (cat # LPH012)
11q rearrangementMLLCytocell (cat # LPH013)
t(9;22)ABL1 / BCRCytocell (cat # LPH038)
14q rearrangementIGHCytocell (cat # LPH014)

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.