T-Cell Receptor (TCR) Gamma Gene Rearrangement, PCR

Test Code

CPT Codes
81342, 84999

Pathologist Interpretation

Preferred Specimen
5 mL whole blood or 3 mL bone marrow aspirate collected in an EDTA (lavender-top) tube • 8 unstained positively charged slides

Minimum Volume
3 mL whole blood • 1 mL bone marrow aspirate • 4 slides • 1 block

Other Acceptable Specimens
Whole blood or bone marrow aspirate collected in a sodium heparin (green-top) tube • Formalin-fixed, paraffin-embedded tissue • Fresh tissue

Do not reject specimens, send to laboratory for screening.

8 unstained sections on glass slides labeled with surgical case number (pathology report required, indicate if fixative is not formalin) Please include pathology report for frozen tissue and FFPE cases (partial/preliminary reports acceptable).

Needle washings (acceptable): in alcohol based fixative (eg. CytoLyt) are acceptable.

Transport Temperature
Fresh tissue: Frozen
All other specimens: Room temperature

Specimen Stability
Whole blood/Bone marrow aspirate
Room temperature: 7 days
Refrigerated: 7 days
Frozen: Unacceptable

Room temperature: 5 years
Refrigerated: 5 years
Frozen: Unacceptable

Fresh, unfixed tissue (acceptable)
Room temperature: See instructions
Refrigerated: See instructions
Frozen -70°C: 1 year

Polymerase Chain Reaction (PCR) • Fragment Analysis

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 FDA. 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

Reference Range
See Laboratory Report

Clinical Significance
This assay which interrogates the T-cell receptor gamma locus (TCRG) by a PCR method based on the BIOMED-2 consensus, is used for establishing clonality of T-cell lymphoid neoplasms and identification of minimal residual disease or early recurrence in patients with a previous diagnosis of a T-cell neoplasm. It can be used in association with T-cell receptor beta (TCBR) PCR assay (Test code 91446 or TCRG/TCRB combo test code 91445), since false-negative results can occur in up to 5-10% of T-cell malignancies when testing TCRG PCR only.

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153

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.