Fluorescence In Situ Hybridization – CLL 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

Chronic lymphocytic leukemia (CLL) is leukemia of small mature B-cells and mostly affect adults age 65 and above.  CLL is the most common lymphoid malignancy accounting for about 11% of all hematological malignancies and 25% of all leukemias.  Up to 50% of patients with CLL may have clonal cytogenetic abnormalities identified on routine chromosome analysis.  However, CLL clones (lymphocytes) do not divide in culture and are resistant to mitogens, thus making routine cytogenetic analysis more difficult.  FISH on the other hand is highly sensitive in detecting the genomic changes that have significant prognostic implications in CLL.


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 CLL panel includes the following probes.

6q deletionD6Z1 / MYBCytocell (cat # LPH016)
trisomy 12D12Z1Cytocell (cat # LPE012R)
11q deletionD11Z1 / ATMCytocell (cat # LPH011)
t(14;18)IGH / BCL2Cytocell (cat # LPH018)
14q rearrangementIGHCytocell (cat # LPH014)
17p deletionp53Cytocell (cat # LPH017)
t(11;14)CCND1 / IGHCytocell (cat # LPH021)
13q deletionRB1 / CTB-163C9Cytocell (cat # LPS011)

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.