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HelpTest ID: TALAF T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), FISH, Adult, Varies
Ordering Guidance
This test is only performed on specimens from patients with T-cell acute lymphoblastic leukemia (T-ALL) who are 31 years and older.
This test is intended for instances when the entire T-ALL fluorescence in situ hybridization (FISH) panel is needed for an adult patient.
This test should NOT be used to screen for residual T-cell acute lymphoblastic leukemia (T-ALL). At follow-up, or if the patient clinically relapses, conventional cytogenetic studies (CHRBM / Chromosome Analysis, Hematologic Disorders, Bone Marrow) are useful to identify cytogenetic changes in the neoplastic clone or the possible emergence of a new therapy-related myeloid clone. Additionally, targeted T-ALL FISH probes can be evaluated based on the abnormalities identified in the diagnostic study.
If targeted T-cell ALL FISH probes are preferred, order TALMF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), Specified FISH, Varies.
If this test is ordered on a patient 30 years or younger, this test will be canceled and automatically reordered by the laboratory as 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 BALAF / B-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), Adult, FISH, Varies is ordered concurrently with this test, the laboratory may cancel TALAF and automatically reorder as TALMF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), Specified FISH, Varies with the following FISH probes: TLX3/BCL11B, break-apart TRB, break-apart TRAD, MLLT10/PICALM, TAL1/STIL. If an abnormality is identified that would result in reflex testing in TALAF, the same reflex testing will be performed in the TALMF. This cancelation is necessary to avoid duplicate testing. Probes for break-apart PDGFRB, break-apart JAK2, CDKN2A/D9Z1, ABL1/BCR, break-apart ABL1, break-apart MLL, TP53/D17Z1 will still be performed as part of the adult B-ALL FISH panel.
For patients with T-cell lymphoma, order TLPDF / T-Cell Lymphoma, Diagnostic FISH, Varies.
For testing paraffin-embedded tissue samples from patients with T-cell lymphoblastic leukemia/lymphoma (T-LBL), order TLBLF / T-Lymphoblastic Leukemia/Lymphoma, FISH, Tissue. If a paraffin-embedded tissue sample is submitted for this test, testing 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 this fluorescence in situ hybridization (FISH) panel should be performed. If there is limited specimen available, only this test will be performed.
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
1. 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.
2. 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, at diagnosis, recurrent common chromosome abnormalities associated with T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) in adult patients
As an adjunct to conventional chromosome studies in patients with T-ALL
Evaluating specimens in which chromosome studies are unsuccessful
This test should not be used to screen for residual T-ALL
Testing Algorithm
This test includes a charge for the probe application, analysis, and professional interpretation of results for 10 probe sets (20 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.
This test is performed as panel testing only using the following analysis algorithm.
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.
The diagnostic adult T-cell acute lymphoblastic leukemia (T-ALL) FISH panel includes testing for the following abnormalities using the FISH probes listed:
t(9p24.1;var) or 9p24.1 rearrangement, JAK2 break-apart
ABL1 amplification or t(9;22)(q34;q11.2), ABL1/BCR
t(11q23;var) or 11q23 rearrangement, MLL(KMT2A) break-apart
1p33 rearrangement or STIL deletion, TAL1/STIL
t(5;14)(q35;q32) or TLX3::BCL11B fusion, TLX3/BCL11B
t(7q34;var) or 7q34 rearrangement, TRB break-apart
t(14q11.2;var) or 14q11.2 rearrangement, TRAD break-apart
t(10;11)(p12;q14) or MLLT10::PICALM fusion, MLLT10/PICALM fusion
t(9q34;var) or 9q34 rearrangement, ABL1 break-apart
t(5q32;var) or 5q32 rearrangement, PDGFRB break-apart
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.
When an MLL(KMT2A) rearrangement is identified, appropriate reflex testing will be performed in an attempt to identify the translocation partner. Probes include identification of t(4;11)(q21;q23) AFF1::MLL(KMT2A) fusion, t(6;11)(q27;q23) MLLT4(AFDN)::MLL(KMT2A) fusion, t(9;11)(p22;q23) MLLT3::MLL(KMT2A) fusion, t(10;11)(p12;q23) MLLT10::MLL(KMT2A) fusion, t(11;19)(q23;p13.1) MLL(KMT2A)::ELL fusion or t(11;19)(q23;p13.3) MLL(KMT2A)::MLLT1 fusion. In the event an 11q23 translocation is identified by chromosome analysis, only the targeted MLL reflex probe will be performed if applicable.
When a TRAD(TCR alpha delta) rearrangement is identified, appropriate reflex testing will be performed in an attempt to identify the translocation partner. Probes include identification of t(10;14)(q24;q11.2) TLX1::TRAD fusion or t(11;14)(p13;q11.2) LMO2::TRAD fusion. In the event a 14q11.2 translocation is identified by chromosome analysis, only the targeted TRAD reflex probe will be performed if applicable.
When a TRB(TCR beta) rearrangement is identified, appropriate reflex testing will be performed in an attempt to identify the translocation partner. Probes include identification of t(7;10)(q34;q24) TRB::TLX1 fusion or t(7;11)(q34;p13) TRB::LMO2 fusion. In the event a 7q34 translocation is identified by chromosome analysis, only the targeted TRB reflex probe will be performed if applicable.
For more information see Acute Leukemias of Ambiguous Lineage Testing Algorithm.
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
Adult ALL (T-cell), FISHSpecimen Type
VariesSpecimen Minimum Volume
Bone marrow: 1 mL; Whole blood: 2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Ambient (preferred) | ||
| Refrigerated | |||
Clinical Information
T-cell acute lymphoblastic leukemia (T-ALL) accounts for approximately 25% of cases of adult lymphoblastic leukemia. 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 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)(p12;q14) |
MLLT10/PICALM |
|
Episomal amplification |
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)(p12;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(7;10)(q34;q24) |
TRB/TLX1 |
|
t(7;11)(q34;p13) |
TRB/LMO2 |
|
t(14q11.2;var) |
TRAD |
|
t(10;14)(q24;q11.2) |
TLX1/TRAD |
|
t(11;14)(p13;q11.2) |
LMO2/TRAD |
|
t(9p24.1;var) |
JAK2 |
|
t(9q34;var) |
ABL1 |
|
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.
Clinical Reference
1. WHO Classification of Tumours Editorial Board, eds. Haematolymphoid tumours. 5th ed. IARC Press; 2024. WHO Classification of Tumours, Volume 11
2. Gesk S, Martin-Subero JI, Harder L, et al. Molecular cytogenetic detection of chromosomal breakpoints in T-cell receptor gene loci. Leukemia. 2003;17(4):738-745
3. Chin M, Mugishima H, Takamura M, et al. Hemophagocytic syndrome and hepatosplenic (gamma)(delta) T-cell lymphoma with isochromosome 7q and 8 trisomy. J Pediatr Hematol Oncol. 2004;26(6):375-378
4. Graux C, Cools J, Michaux L, Vandenberghe, P, Hagemeijer A. Cytogenetics and molecular genetics of T-cell acute lymphoblastic leukemia: from thymocyte to lymphoblast. Leukemia. 2006;20:1496-1510
5. Cayuela JM, Madani A, Sanhes L, Stern MH, Sigaux F. Multiple tumor-suppressor gene 1 inactivation is the most frequent genetic alteration in T-cell acute lymphoblastic leukemia. Blood. 1996;87:2180-2186
6. Hayette S, Tigaud I, Maguer-Satta V, et al. Recurrent involvement of the MLL gene in adult T-lineage acute lymphoblastic leukemia. Blood. 2002;99:4647-4649
7. Graux C, Cools J, Melotte C, et al. Fusion of NUP214 to ABL1 on amplified episomes in T-cell acute lymphoblastic leukemia. Nat Genet. 2004;36:1084-1089
Day(s) Performed
Monday through Friday
Report Available
7 to 10 daysTest 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
88271x20, 88275x10, 88291x1-FISH Probe, Analysis, Interpretation; 10 probe sets
88271x2, 88275x1-FISH Probe, Analysis; each additional probe set (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TALAF | Adult ALL (T-cell), FISH | 101663-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 609558 | Result Summary | 50397-9 |
| 609559 | Interpretation | 69965-2 |
| 609560 | Result Table | 93356-4 |
| 609561 | Result | 62356-1 |
| GC071 | Reason for Referral | 42349-1 |
| GC072 | Specimen | 31208-2 |
| 609562 | Source | 31208-2 |
| 609563 | Method | 85069-3 |
| 609564 | Additional Information | 48767-8 |
| 609565 | Disclaimer | 62364-5 |
| 609566 | Released By | 18771-6 |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| TALAB | Probe, Each Additional (TALAF) | No, (Bill Only) | No |
Forms
If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.
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