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Test Code TALMF T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), Specified FISH, Varies


Ordering Guidance


This test is intended for instances when limited T-cell acute lymphoblastic leukemia (ALL) fluorescence in situ hybridization (FISH) probes are needed. The FISH probes to be analyzed must be specified on the ordering request. If specific probes are not included with this test request, testing will be delayed and may be canceled and automatically reordered by the laboratory as TALAF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), FISH, Adult, Varies or TALPF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), FISH, Pediatric, Varies depending on the age of the patient.

 

If a complete T-cell ALL FISH panel is preferred for an adult patient who is 31 years or older, order TALAF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), FISH, Adult, Varies.

 

If a complete T-cell ALL FISH panel is preferred for a pediatric patient who is 30 years or younger, order TALPF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), FISH, Pediatric, Varies.

 

If this test is ordered and the laboratory is informed that the patient is on a Children's Oncology Group (COG) protocol, this test will be canceled and automatically reordered by the laboratory as COGTF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), Children's Oncology Group Enrollment Testing, FISH, Varies.

 

If the patient clinically relapses, a conventional chromosome study is useful to identify cytogenetic changes in the neoplastic clone or the possible emergence of a new therapy-related myeloid clone.

 

For patients with T-cell lymphoma, order TLPDF / T-Cell Lymphoma, Diagnostic FISH, Varies.

 

For testing paraffin-embedded tissue samples from patients with T-lymphoblastic leukemia/lymphoma (T-LBL), order TLBLF / T-Cell Lymphoblastic Leukemia/Lymphoma, FISH, Tissue. If a paraffin-embedded tissue sample is submitted for this test, this test will be canceled and TLBLF will be added and performed as the appropriate test.



Additional Testing Requirements


At diagnosis, conventional cytogenetic studies (CHRBM / Chromosome Analysis, Hematologic Disorders, Bone Marrow) and a complete TALAF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), FISH, Adult, Varies or TALPF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), FISH, Pediatric, Varies should be performed, depending on patient's age. If there is limited specimen available, only fluorescence in situ hybridization testing will be performed.



Shipping Instructions


Advise Express Mail or equivalent if not on courier service.



Necessary Information


1. A list of probes requested for analysis is required. Probes available for this test are listed in the Testing Algorithm section.

2. A reason for testing must be provided. If this information is not provided, an appropriate indication for testing may be entered by Mayo Clinic Laboratories.

3. A flow cytometry and/or a bone marrow pathology report should be submitted with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.



Specimen Required


Submit only 1 of the following specimens:

 

Preferred:

Specimen Type: Bone marrow

Container/Tube:

Preferred: Yellow top (ACD)

Acceptable: Green top (heparin) or lavender top (EDTA)

Specimen Volume: 2 to 3 mL

Collection Instructions:

1. It is preferable to send the first aspirate from the bone marrow collection.

2. Invert several times to mix bone marrow.

3. Send bone marrow specimen in original tube. Do not aliquot.

 

Acceptable:

Specimen Type: Whole blood

Container/Tube:

Preferred: Yellow top (ACD)

Acceptable: Green top (heparin) or lavender top (EDTA)

Specimen Volume: 6 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send whole blood specimen in original tube. Do not aliquot.


Useful For

Detecting recurrent common chromosome abnormalities associated with T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) using client-specified probes

 

An adjunct to conventional chromosome studies in patients with T-ALL

 

Evaluating specimens in which standard cytogenetic studies are unsuccessful

 

Identifying and tracking known chromosome abnormalities in patients with T-ALL and monitoring response to therapy

Testing Algorithm

This test includes a charge for the probe application, analysis, and professional interpretation of results for one probe set (2 individual fluorescence in situ hybridization [FISH] probes). Additional charges will be incurred for all reflex or additional probe sets performed. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cells are available for analysis, no analysis charges will be incurred.

 

If targeted FISH testing is desired, or if the patient has a known abnormality, specify the abnormality and request the accompanying FISH probe, as indicated below.

 

When specified, any of the following probes will be performed:

1p33 rearrangement or STIL deletion, request probe TAL1/STIL

t(5;14)(q35;q32) or TLX3::BCL11B fusion, request probe TLX3/BCL11B

t(5q32;var) or 5q32 rearrangement, request probe PDGFRB break-apart

t(7q34;var) or 7q34 rearrangement, request probe TRB break-apart

t(6;7)(q23;q34) or MYB::TRB fusion, request probe MYB/TRB

t(7;10)(q34;q24) or TRB::TLX1 fusion, request probe TRB/TLX1

t(7;11)(q34;p15) or TRB::LMO1 fusion, request probe TRB/LMO1

t(7;11)(q34;p13) or TRB::LMO2 fusion, request probe TRB/LMO2

+9/9p-, request probe CDKN2A/D9Z1

t(9p24.1;var) or 9p24.1 rearrangement, request probe JAK2 break-apart

ABL1 amplification or t(9;22)(q34;q11.2), request probe ABL1/BCR

t(9q34;var) or 9q34 rearrangement, request probe ABL1 break-apart

t(10;11)(p12;q14) or MLLT10::PICALM fusion, request probe MLLT10/PICALM

t(11q23;var) or 11q23 rearrangement, request probe MLL (KMT2A) break-apart

t(4;11)(q21;q23) or AFF1::MLL(KMT2A) fusion, request probe AFF1/MLL

t(6;11)(q27;q23) or MLLT4(AFDN)::MLL(KMT2A) fusion, request probe MLLT4(AFDN)/MLL

t(9;11)(p22;q23) or MLLT3::MLL(KMT2A) fusion, request probe MLLT3/MLL

t(10;11)(p12;q23) or MLLT10::MLL(KMT2A) fusion, request probe MLLT10/MLL

t(11;19)(q23;p13.1) or MLL(KMT2A)::ELL fusion, request probe MLL/ELL

t(11;19)(q23;p13.3) or MLL(KMT2A)::MLLT1 fusion, request probe MLL/MLLT1

t(14q11.2;var) or 14q11.2 rearrangement, request probe TRAD break-apart

t(8;14)(q24.1;q11.2) or MYC::TRAD fusion, request probe MYC/TRAD

t(10;14)(q24;q11.2) or TLX1::TRAD fusion, request probe TLX1/TRAD

t(11;14)(p15;q11.2) or LMO1::TRAD fusion, request probe LMO1/TRAD

t(11;14)(p13;q11.2) or LMO2::TRAD fusion, request probe LMO2/TRAD

-17/17p-, request probe TP53/D17Z1

 

Appropriate ancillary probes may be performed at consultant discretion to render comprehensive assessment. Any additional probes will have the results included within the final report and will be performed at an additional charge.

Method Name

Fluorescence In Situ Hybridization (FISH)

Reporting Name

ALL (T-cell), Specified FISH

Specimen Type

Varies

Specimen Minimum Volume

Bone marrow: 1 mL; Whole blood: 2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Ambient (preferred)
  Refrigerated 

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

Acute lymphoblastic leukemia (ALL) accounts for approximately 70% of all childhood leukemia cases (ages 0 to 19 years), making it the most common childhood cancer.

 

Approximately 85% of pediatric cases of ALL are of B-cell lineage (B-ALL) and 15% are of T-cell lineage (T-ALL). T-ALL is more common in adolescents than younger children and accounts for 25% of adult ALL. When occurring as a primary lymphoblastic lymphoma (LBL), approximately 90% are T-cell lineage versus only 10% B-cell lineage. T-LBL often present as a mediastinal mass in younger patients, with or without concurrent bone marrow involvement.

 

An abnormal karyotype is found in 50% to 70% of T-ALL cases, although many of the classic abnormalities are "cryptic" by conventional chromosome studies and must be identified by fluorescence in situ hybridization (FISH) studies and are associated with various prognoses. One predictive marker, amplification of the ABL1 gene region, has been identified in 5% of T-ALL, and these patients may be responsive to targeted tyrosine kinase inhibitors.

 

A summary of the characteristic chromosome abnormalities identified in T-ALL is listed in the following table.

 

Table. Common Chromosome Abnormalities in T-cell Acute Lymphoblastic Leukemia

Cytogenetic change

Genes involved

del(1p33)

TAL1/STIL

t(5;14)(q35;q32)

TLX3/BCL11B

t(5q32;var)

PDGFRB

t(10;11)(p13;q14)

MLLT10/PICALM

Episomal amplification

ABL1

del(9p)

CDKN2A(p16)

t(9p24.1;var)

JAK2

t(9q34;var)

ABL1

t(11q23;var)

MLL(KMT2A)

t(4;11)(q21;q23)

AFF1/MLL(KMT2A)

t(6;11)(q27;q23)

MLLT4(AFDN)/MLL(KMT2A)

t(9;11)(p22;q23)

MLLT3/MLL(KMT2A)

t(10;11)(p13;q23)

MLLT10/MLL(KMT2A)

t(11;19)(q23;p13.1)

MLL(KMT2A)/ELL

t(11;19)(q23;p13.3)

MLL(KMT2A)/MLLT1

t(7q34;var)

TRB

t(6;7)(q23;q34)

MYB/TRB

t(7;10)(q34;q24)

TRB/TLX1

t(7;11)(q34;p15)

TRB/LMO1

t(7;11)(q34;p13)

TRB/LMO2

t(14q11.2;var)

TRAD

t(8;14)(q24.1;q11.2)

MYC/TRAD

t(10;14)(q24;q11.2)

TLX1/TRAD

t(11;14)(p15;q11.2)

LMO1/TRAD

t(11;14)(p13;q11.2)

LMO2/TRAD

del(17p)

TP53

Complex karyotype (≥4 abnormalities)

 

Reference Values

An interpretive report will be provided.

Interpretation

A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal reference range for any given probe set.

 

The absence of an abnormal clone does not rule out the presence of a neoplastic disorder.

Cautions

This test is not approved by the US Food and Drug Administration, and it is best used as an adjunct to existing clinical and pathologic information.

 

Bone marrow is the preferred sample type for this fluorescence in situ hybridization (FISH) test. If bone marrow is not available, a blood specimen may be used if there are neoplastic cells in the blood specimen (as verified by a hematopathologist).

 

If no FISH signals are observed post-hybridization, the case will be released indicating a lack of FISH results.

Method Description

This test is performed using commercially available and laboratory-developed probes. Deletion of the CDKN2A locus on chromosome 9 and TP53 on chromosome 17 are detected using enumeration strategy probes. Rearrangements involving TAL1/STIL, PDGFRB, TRB, JAK2, ABL1, MLL(KMT2A), and TRAD are detected using dual-color break-apart (BAP) strategy probes. Dual-color, dual-fusion fluorescence in situ hybridization (D-FISH) strategy probe sets are used to detect t(5;14), t(9;22), t(10;11), and in reflex testing when rearrangements of MLL(KMT2A), TRB, or TRAD genes are detected. Amplification of the ABL1 gene region is detected using a D-FISH probe strategy. For enumeration and BAP strategy probe sets, 100 interphase nuclei are scored; 200 interphase nuclei are scored when D-FISH probes are used. All results are expressed as the percent abnormal nuclei.(Unpublished Mayo method)

Day(s) Performed

Monday through Friday

Report Available

7 to 10 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

88271x2, 88275x1, 88291x1-FISH Probe, Analysis, Interpretation; 1 probe set

88271x2, 88275x1 - FISH Probe, Analysis; each additional probe set (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TALMF ALL (T-cell), Specified FISH In Process

 

Result ID Test Result Name Result LOINC Value
614325 Result Summary 50397-9
614326 Interpretation 69965-2
614327 Result Table 93356-4
614328 Result 62356-1
GC134 Reason for Referral 42349-1
GC135 Probes Requested 78040-3
GC136 Specimen 31208-2
614329 Source 31208-2
614330 Method 85069-3
614331 Additional Information 48767-8
614332 Disclaimer 62364-5
614333 Released By 18771-6

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
TALMB Probe, Each Additional (TALMF) No, (Bill Only) No