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

Test Code

TCELL GAMMA

Quest Code

90509

Alias/See Also

90509

CPT Codes
81342, 84999 (HCPCS; G0452 ZB0UW)

Includes

Pathologist Interpretation

Preferred Specimen

5 mL whole blood collected in an EDTA (lavender-top) tube or
3 mL bone marrow aspirate in an EDTA (lavender-top) tube

Minimum Volume

3 mL whole blood • 1 mL bone marrow aspirate • 4 unstained charged (+) slides

Other Acceptable Specimens

Formalin fixed paraffin embedded tissue • Fresh tissue in a sterile transport tube • Whole blood or bone marrow collected in a sodium heparin (green-top) tube

Instructions

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 (e.g. CytoLyt®) are acceptable.

Do not reject specimens, send to laboratory for screening.

Transport Temperature

All other specimens: Room temperature
Fresh Tissue: Frozen

Specimen Stability

Whole blood and bone marrow aspirate
Room temperature: 7 days
Refrigerated: 7 days
Frozen: Unacceptable

FFPE tissue/slides
Room temperature: 5 years
Refrigerated: 5 years
Frozen: Unacceptable

Fresh tissue
Room temperature: See Collection Instructions
Refrigerated: See Collection Instructions
Frozen -20° C: See Collection Instructions
Frozen -70° C: 1 year

Methodology
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

Report Available

Maximum Laboratory Turn Around Time 8 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
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042

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.