Ordering Recommendations

Indications for testing include:
  1. Identification of clonal T cell populations suggestive of T cell malignancies
  2. Monitoring and evaluation of disease recurrence

A completed test request form must be included with the specimen. Ensure that the following information is included on the test request form:
  • Clinical Indication
  • ICD-10 Diagnosis Code
  • If Surgical Pathology needs to perform lymphoma protocol, this must be notated on the requisition

Performed

Monday - Friday

Methodology

Polymerase Chain Reaction / Fragment Analysis

Reported

Routine: 7 days

Synonyms

  • T Cell Receptor Gamma Gene Rearrangement
  • T-Cell Receptor Gamma Gene Rearrangement
  • T Cell Receptor Gene Rearrangement
  • T-Cell Receptor Gene Rearrangement
  • T-Cell Gene Rearrangement
  • T Cell Gene Rearrangement
  • TCR Gamma Gene Rearrangements
  • TCRG Gene
  • T Cell Clonality
  • T Cell Lymphoma
  • Lymphoproliferative Disorders
  • Clinical Genomics

Performing Lab

Surgical Pathology: Specimen Preparation and Storage of FFPE ONLY
Clinical Genomics: Testing Laboratory

Turnaround Time

After specimen receipt in the Clinical Genomics Lab, results are generally available within 7 days.

Add-on Eligibility

Yes
  • Add-on orders for bone marrow specimens must be requested within 5 days of collection due to specimen stability.

*If DNA has been extracted previously for other Clinical Genomics tests, this is stored for 6 weeks and may qualify for add-on

Specimen Type

  1. Bone Marrow
  2. Tumor Tissue

Specimen Preparation

Tissue Specimens
  1. Formalin Fix the specimen by submerging the Tissue in 10% Neutral Buffered Formalin
  2. Send the Formalin-Fixed Tissue to the Surgical Pathology Lab
  3. The Surgical Pathology Lab will paraffin-embed the tissue and prepare a Tissue Block
  4. The Tissue block will be sent to the Clinical Genomics Laboratory for testing

Specimen Volume

Bone Marrow:
  • Adult: 3 mL (Minimum: 1 mL)
  • Pediatric: 1 mL (Minimum: 1 mL)

Tumor Tissue:
  • Fresh Tissue Size: 1 cm3 (Minimum: 0.5 cm3)
    • Specimen must contain a region with at least 20% tumor
  • Fixative Volume: 15 times the volume of the tissue

*This refers to specimen volume at collection prior to any processing

Collection Container

Bone Marrow:
*Bone marrow specimens can be sent directly to the Clinical Genomics Laboratory
 
3.0 mL EDTA Whole Blood Tube (Lavender Top Vacutainer)

Tumor Tissue:
*Tissue specimens need to be sent to Surgical Pathology after collection so that the specimen can be processed prior to transport to the Clinical Genomics Laboratory. Do NOT send directly to Clinical Genomics.
 
  1. Formalin Container
  • EXCEPT for cases of suspected lymphoma
 
OR
 
  1. Non-Sterile Liquid-Proof Container
  • Medium to large specimens for routine processing that do not fit in prefilled formalin containers can be can be sent in specimen containers without formalin
  • Surgical Pathology staff will add formalin when the specimen is recieved in the lab

Unacceptable Conditions

  1. Severely clotted or grossly hemolyzed specimens
  2. The provider will be contacted regarding receipt of non-validated specimen types
  3. Specimens that have been improperly collected, stored, or transported
  • Specimens collected in preservatives other than EDTA
    • ACD tubes are also accepted, but EDTA is preferred
  • Serum or plasma
  • Tissue specimens that have been preserved in fixatives other than formalin
  • Tissue specimens that have been preserved in heavy metal fixatives (B-4 or B-5)
  • Tissue sections submitted on slides
  • Specimens that have been frozen
  • Commingled specimens
  1. Specimens with insufficient volume for testing
  2. Unlabeled or mislabeled specimens

Storage/Transport Temperature

*Tissue specimens should be collected and transported to the Surgical Pathology Lab for FFPE Tissue Block preparation
 
Transport Instructions
Collection Location Specimen Type Transport Temperature Timeframe
ED/
Inpatient		 Bone Marrow Room Temperature Specimen must be received by the Clinical Genomics Lab within 24 hours of collection
Refrigerated (Ice Packs) Specimen must be received by the Clinical Genomics Lab within 5 days of collection
Fresh Specimen Room Temperature Specimen must be received by the Surgical Pathology Lab within 1 hour of collection
Refrigerated (Ice Packs) Specimen must be received by the Surgical Pathology Lab within 24 hours of collection
Formalin Fixed Specimen Room Temperature Specimen must be received by the Surgical Pathology Lab within 24 hours of collection
Laboratory/
Outpatient/
Off-Site 		 Bone Marrow Room Temperature Specimen must be received by the Clinical Genomics Lab within 24 hours of collection
Refrigerated (Ice Packs) Specimen must be received by the Clinical Genomics Lab within 5 days of collection
Fresh Specimen Room Temperature Specimen must be received by the Surgical Pathology Lab within 1 hour of collection
Refrigerated (Ice Packs) Specimen must be received by the Surgical Pathology Lab within 24 hours of collection
Formalin Fixed Specimen Room Temperature Specimen must be received by the Surgical Pathology Lab within 24 hours of collection

Storage:
  • Bone Marrow: Refrigerated
  • Fixed Specimens: Room Temperature
  • Fresh Specimens: Refrigerated

Stability (from collection to initiation)

Stability:

Bone Marrow:
  • Room Temperature: 24 hours
  • Refrigerated: 5 days
  • Frozen: Unacceptable

Tumor Tissue:
Formalin-Fixed Specimens
  • Room Temperature: 1 week
  • Refrigerated: Not recommended
  • Frozen: Unacceptable
Sterile Container
  • Room Temperature: 3 hours
  • Refrigerated: 24 hours
  • Frozen: Unacceptable
FFPE Tissue Block
  • Room Temperature: Indefinitely
  • Refrigerated: Indefinitely
  • Frozen: Unacceptable

Extracted DNA:
  • Room Temperature: Unacceptable
  • Refrigerated: Unacceptable
  • Frozen: Indefinitely

Laboratory Storage:
  • Bone Marrow: Refrigerated
  • Tumor Tissue:
    • All tissue specimens are stored at the Surgical Pathology Lab
      • Fixed Specimens: Room Temperature
      • Fresh Specimens: Refrigerated
      • FFPE Tissue Blocks: Room Temperature
  • Extracted DNA: Frozen

Laboratory Retention: 
  • Bone Marrow: 1 month
  • FFPE Tissue Blocks: Returned to Surgical Pathology Lab after testing is completed
  • Extracted DNA: 6 weeks

Collection Instructions

Collection Instructions:

Bone Marrow
  1. Follow the correct order of draw when collecting with additional orders and tube types:
     

Tumor Tissue

Routine Small and Medium Sized Specimens
  1. Collect Tissue specimen and place into a Sterile Container with enough 10% formalin to cover the tissue by at least 2 - 3 inches.
  • Specimens must contain a region with at least 20% tumor
  • Breast Specimens: Immerse in fixative within 1 hour of biopsy or resection procedure for optimum tissue processing. Document the time that the tissue was placed into formalin.
  • Suspicion of Lymphoma: Send FRESH. Do NOT place specimen into formalin.
*Must state that lymphoma protocol is needed on requisition
 
  1. Specimens should be delivered to the Surgical Pathology Lab as soon as possible.  If delivery of a resection specimen to the Surgical Pathology department is delayed (e.g. specimens from remote sites), the tumor should be bisected prior to immersion in fixative.
  • It is important that the surgeon ensure that the identity of the resection margins is retained in the bisected specimen
  • Alternatively, the margins may be separately submitted
  1. Ensure that the cap is tightly secured on the Collection Container
  2. The time of removal of the tissue and the time of immersion of the tissue in fixative should be recorded and submitted to the laboratory

Routine Large Sized Specimens
  1. Collect tissue specimen and place in large leak-proof container
  2. Bring specimen to the Surgical Pathology laboratory immediately, or refrigerate

Specimen Container Labeling Instructions:

Bone Marrow
  1. When labeling collection tubes, leave a small window visible for the lab to assess the fill volume and sample integrity
  2. Ensure that the barcode is in the correct orientation.
 
  1. Specimen should be transported directly to the Clinical Genomics Laboratory

Tumor Tissue
  1. Specimen Containers submitted to Surgical Pathology must be labeled with the following patient information:
  • First and Last Name
  • Date of Birth
  • Medical Record Number
  • CSN Number
  • Name of Specimen Site/Source
*If more than one site is sampled, a separate collection container must be submitted for each site
 
  1. Check all labeling of containers prior to leaving the collection site
 
  1. Place the following in a biohazard bag for transport to the Surgical Pathology Lab:
*If more than one site is sampled, all specimen material collected must be packaged and separated according to specimen site
 
  • Specimen Containers
  • Specimen Requisitions

Processing Instructions:

Tumor Tissue
  1. Formalin Fix fresh tissues in 10% Neutral Buffered Formalin
  2. Paraffin-embed the fixed tissue and prepare FFPE Tissue Block
  • Specimens must contain a region with at least 20% tumor
 
  1. Protect specimen from excessive heat and transport one of the following to the Clinical Genomics Laboratory for testing:
  • Tissue Block
    • Tissue block will be returned to the Surgical Pathology Lab after testing
  • Two to four 10 micron sections
    • Do not submit tissue sections on slides
  1. Include the Surgical Pathology report with the specimen

Reference Interval

Not Detected: Negative for clonal rearrangement of the T cell receptor gamma gene

Interpretive Data

Rearrangement of the T cell receptor gamma chain (TCRG) gene occurs during ontogeny in T lymphocytes. The structure of these rearranged genes can be examined as a means of detecting a clonal population of T cells, such as is present in lymphoma and other T cell malignancies. A polymerase chain reaction (PCR) assay, in which primers are designed to produce small amplicons from the junction points of the rearranged TCRG gene segments, can be used for this purpose.  When every cell in a population has rearranged their TCRG genes differently, the PCR assay will produce a large number of products, each with a slightly different size, indicating a polyclonal population.  If a large number of cells harbor the same rearrangement of TCRG gene segments, the PCR product produced from these cells will be in much greater concentration than those produced from a polyclonal cell population, thus resulting in a "predominant" PCR amplicon size.  This is taken as evidence of a monoclonal population. 

Methodology: Polymerase chain reaction and capillary gel electrophoresis

Limitations: Positive results are highly suggestive of malignancy; however, a positive result should not be used as the sole criterion for diagnosis. Both positive and negative results should be interpreted in the context of all clinical and laboratory findings. Up to 20% of T cell neoplasms can yield a false-negative result in this assay. Thus, a negative result with this assay cannot be used to exclude a T cell neoplasm.

This test was developed and its performance characteristics determined by the UC San Diego Health System Clinical Genomics Laboratory. It has not been cleared or approved by the US Food and Drug Administration. FDA clearance or approval is not required for clinical use. The result of this test should be interpreted using all relevant clinical data and should not be used alone for clinical diagnosis or patient management decisions.
Ordering

Ordering Recommendations

Indications for testing include:
  1. Identification of clonal T cell populations suggestive of T cell malignancies
  2. Monitoring and evaluation of disease recurrence

A completed test request form must be included with the specimen. Ensure that the following information is included on the test request form:
  • Clinical Indication
  • ICD-10 Diagnosis Code
  • If Surgical Pathology needs to perform lymphoma protocol, this must be notated on the requisition

Performed

Monday - Friday

Methodology

Polymerase Chain Reaction / Fragment Analysis

Reported

Routine: 7 days

Synonyms

  • T Cell Receptor Gamma Gene Rearrangement
  • T-Cell Receptor Gamma Gene Rearrangement
  • T Cell Receptor Gene Rearrangement
  • T-Cell Receptor Gene Rearrangement
  • T-Cell Gene Rearrangement
  • T Cell Gene Rearrangement
  • TCR Gamma Gene Rearrangements
  • TCRG Gene
  • T Cell Clonality
  • T Cell Lymphoma
  • Lymphoproliferative Disorders
  • Clinical Genomics

Performing Lab

Surgical Pathology: Specimen Preparation and Storage of FFPE ONLY
Clinical Genomics: Testing Laboratory

Turnaround Time

After specimen receipt in the Clinical Genomics Lab, results are generally available within 7 days.

Add-on Eligibility

Yes
  • Add-on orders for bone marrow specimens must be requested within 5 days of collection due to specimen stability.

*If DNA has been extracted previously for other Clinical Genomics tests, this is stored for 6 weeks and may qualify for add-on
Collection

Specimen Type

  1. Bone Marrow
  2. Tumor Tissue

Specimen Preparation

Tissue Specimens
  1. Formalin Fix the specimen by submerging the Tissue in 10% Neutral Buffered Formalin
  2. Send the Formalin-Fixed Tissue to the Surgical Pathology Lab
  3. The Surgical Pathology Lab will paraffin-embed the tissue and prepare a Tissue Block
  4. The Tissue block will be sent to the Clinical Genomics Laboratory for testing

Specimen Volume

Bone Marrow:
  • Adult: 3 mL (Minimum: 1 mL)
  • Pediatric: 1 mL (Minimum: 1 mL)

Tumor Tissue:
  • Fresh Tissue Size: 1 cm3 (Minimum: 0.5 cm3)
    • Specimen must contain a region with at least 20% tumor
  • Fixative Volume: 15 times the volume of the tissue

*This refers to specimen volume at collection prior to any processing

Collection Container

Bone Marrow:
*Bone marrow specimens can be sent directly to the Clinical Genomics Laboratory
 
3.0 mL EDTA Whole Blood Tube (Lavender Top Vacutainer)

Tumor Tissue:
*Tissue specimens need to be sent to Surgical Pathology after collection so that the specimen can be processed prior to transport to the Clinical Genomics Laboratory. Do NOT send directly to Clinical Genomics.
 
  1. Formalin Container
  • EXCEPT for cases of suspected lymphoma
 
OR
 
  1. Non-Sterile Liquid-Proof Container
  • Medium to large specimens for routine processing that do not fit in prefilled formalin containers can be can be sent in specimen containers without formalin
  • Surgical Pathology staff will add formalin when the specimen is recieved in the lab

Unacceptable Conditions

  1. Severely clotted or grossly hemolyzed specimens
  2. The provider will be contacted regarding receipt of non-validated specimen types
  3. Specimens that have been improperly collected, stored, or transported
  • Specimens collected in preservatives other than EDTA
    • ACD tubes are also accepted, but EDTA is preferred
  • Serum or plasma
  • Tissue specimens that have been preserved in fixatives other than formalin
  • Tissue specimens that have been preserved in heavy metal fixatives (B-4 or B-5)
  • Tissue sections submitted on slides
  • Specimens that have been frozen
  • Commingled specimens
  1. Specimens with insufficient volume for testing
  2. Unlabeled or mislabeled specimens

Storage/Transport Temperature

*Tissue specimens should be collected and transported to the Surgical Pathology Lab for FFPE Tissue Block preparation
 
Transport Instructions
Collection Location Specimen Type Transport Temperature Timeframe
ED/
Inpatient		 Bone Marrow Room Temperature Specimen must be received by the Clinical Genomics Lab within 24 hours of collection
Refrigerated (Ice Packs) Specimen must be received by the Clinical Genomics Lab within 5 days of collection
Fresh Specimen Room Temperature Specimen must be received by the Surgical Pathology Lab within 1 hour of collection
Refrigerated (Ice Packs) Specimen must be received by the Surgical Pathology Lab within 24 hours of collection
Formalin Fixed Specimen Room Temperature Specimen must be received by the Surgical Pathology Lab within 24 hours of collection
Laboratory/
Outpatient/
Off-Site 		 Bone Marrow Room Temperature Specimen must be received by the Clinical Genomics Lab within 24 hours of collection
Refrigerated (Ice Packs) Specimen must be received by the Clinical Genomics Lab within 5 days of collection
Fresh Specimen Room Temperature Specimen must be received by the Surgical Pathology Lab within 1 hour of collection
Refrigerated (Ice Packs) Specimen must be received by the Surgical Pathology Lab within 24 hours of collection
Formalin Fixed Specimen Room Temperature Specimen must be received by the Surgical Pathology Lab within 24 hours of collection

Storage:
  • Bone Marrow: Refrigerated
  • Fixed Specimens: Room Temperature
  • Fresh Specimens: Refrigerated

Stability (from collection to initiation)

Stability:

Bone Marrow:
  • Room Temperature: 24 hours
  • Refrigerated: 5 days
  • Frozen: Unacceptable

Tumor Tissue:
Formalin-Fixed Specimens
  • Room Temperature: 1 week
  • Refrigerated: Not recommended
  • Frozen: Unacceptable
Sterile Container
  • Room Temperature: 3 hours
  • Refrigerated: 24 hours
  • Frozen: Unacceptable
FFPE Tissue Block
  • Room Temperature: Indefinitely
  • Refrigerated: Indefinitely
  • Frozen: Unacceptable

Extracted DNA:
  • Room Temperature: Unacceptable
  • Refrigerated: Unacceptable
  • Frozen: Indefinitely

Laboratory Storage:
  • Bone Marrow: Refrigerated
  • Tumor Tissue:
    • All tissue specimens are stored at the Surgical Pathology Lab
      • Fixed Specimens: Room Temperature
      • Fresh Specimens: Refrigerated
      • FFPE Tissue Blocks: Room Temperature
  • Extracted DNA: Frozen

Laboratory Retention: 
  • Bone Marrow: 1 month
  • FFPE Tissue Blocks: Returned to Surgical Pathology Lab after testing is completed
  • Extracted DNA: 6 weeks

Collection Instructions

Collection Instructions:

Bone Marrow
  1. Follow the correct order of draw when collecting with additional orders and tube types:
     

Tumor Tissue

Routine Small and Medium Sized Specimens
  1. Collect Tissue specimen and place into a Sterile Container with enough 10% formalin to cover the tissue by at least 2 - 3 inches.
  • Specimens must contain a region with at least 20% tumor
  • Breast Specimens: Immerse in fixative within 1 hour of biopsy or resection procedure for optimum tissue processing. Document the time that the tissue was placed into formalin.
  • Suspicion of Lymphoma: Send FRESH. Do NOT place specimen into formalin.
*Must state that lymphoma protocol is needed on requisition
 
  1. Specimens should be delivered to the Surgical Pathology Lab as soon as possible.  If delivery of a resection specimen to the Surgical Pathology department is delayed (e.g. specimens from remote sites), the tumor should be bisected prior to immersion in fixative.
  • It is important that the surgeon ensure that the identity of the resection margins is retained in the bisected specimen
  • Alternatively, the margins may be separately submitted
  1. Ensure that the cap is tightly secured on the Collection Container
  2. The time of removal of the tissue and the time of immersion of the tissue in fixative should be recorded and submitted to the laboratory

Routine Large Sized Specimens
  1. Collect tissue specimen and place in large leak-proof container
  2. Bring specimen to the Surgical Pathology laboratory immediately, or refrigerate

Specimen Container Labeling Instructions:

Bone Marrow
  1. When labeling collection tubes, leave a small window visible for the lab to assess the fill volume and sample integrity
  2. Ensure that the barcode is in the correct orientation.
 
  1. Specimen should be transported directly to the Clinical Genomics Laboratory

Tumor Tissue
  1. Specimen Containers submitted to Surgical Pathology must be labeled with the following patient information:
  • First and Last Name
  • Date of Birth
  • Medical Record Number
  • CSN Number
  • Name of Specimen Site/Source
*If more than one site is sampled, a separate collection container must be submitted for each site
 
  1. Check all labeling of containers prior to leaving the collection site
 
  1. Place the following in a biohazard bag for transport to the Surgical Pathology Lab:
*If more than one site is sampled, all specimen material collected must be packaged and separated according to specimen site
 
  • Specimen Containers
  • Specimen Requisitions

Processing Instructions:

Tumor Tissue
  1. Formalin Fix fresh tissues in 10% Neutral Buffered Formalin
  2. Paraffin-embed the fixed tissue and prepare FFPE Tissue Block
  • Specimens must contain a region with at least 20% tumor
 
  1. Protect specimen from excessive heat and transport one of the following to the Clinical Genomics Laboratory for testing:
  • Tissue Block
    • Tissue block will be returned to the Surgical Pathology Lab after testing
  • Two to four 10 micron sections
    • Do not submit tissue sections on slides
  1. Include the Surgical Pathology report with the specimen
Result Interpretation

Reference Interval

Not Detected: Negative for clonal rearrangement of the T cell receptor gamma gene

Interpretive Data

Rearrangement of the T cell receptor gamma chain (TCRG) gene occurs during ontogeny in T lymphocytes. The structure of these rearranged genes can be examined as a means of detecting a clonal population of T cells, such as is present in lymphoma and other T cell malignancies. A polymerase chain reaction (PCR) assay, in which primers are designed to produce small amplicons from the junction points of the rearranged TCRG gene segments, can be used for this purpose.  When every cell in a population has rearranged their TCRG genes differently, the PCR assay will produce a large number of products, each with a slightly different size, indicating a polyclonal population.  If a large number of cells harbor the same rearrangement of TCRG gene segments, the PCR product produced from these cells will be in much greater concentration than those produced from a polyclonal cell population, thus resulting in a "predominant" PCR amplicon size.  This is taken as evidence of a monoclonal population. 

Methodology: Polymerase chain reaction and capillary gel electrophoresis

Limitations: Positive results are highly suggestive of malignancy; however, a positive result should not be used as the sole criterion for diagnosis. Both positive and negative results should be interpreted in the context of all clinical and laboratory findings. Up to 20% of T cell neoplasms can yield a false-negative result in this assay. Thus, a negative result with this assay cannot be used to exclude a T cell neoplasm.

This test was developed and its performance characteristics determined by the UC San Diego Health System Clinical Genomics Laboratory. It has not been cleared or approved by the US Food and Drug Administration. FDA clearance or approval is not required for clinical use. The result of this test should be interpreted using all relevant clinical data and should not be used alone for clinical diagnosis or patient management decisions.

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