Test 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.
-If this test is ordered on a patient 30 years of age 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 cancellation 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.
If limited T-cell ALL FISH probes are preferred, order TALMF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), Specified FISH, Varies.
At follow-up, conventional cytogenetic studies (CHRBM / Chromosome Analysis, Hematologic Disorders, Bone Marrow) and targeted T-ALL FISH probes can be evaluated based on the abnormalities identified in the diagnostic study. Order TALMF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), Specified FISH, Varies and request specific probes or abnormalities.
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-cell lymphoblastic lymphoma, 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
A reason for testing and 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; however, appropriate testing and interpretation may be compromised or delayed. If not provided, an appropriate indication for testing may be entered by Mayo Clinic Laboratories.
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: 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.
Forms
If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.
Secondary ID
609557Useful For
Detecting a neoplastic clone associated with the common chromosome abnormalities and classic rearrangements observed in adult patients with T-cell acute lymphoblastic leukemia (T-ALL)
An adjunct to conventional chromosome studies in patients with T-ALL
Evaluating specimens in which standard cytogenetic analysis is unsuccessful
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
TALAB | Probe, Each Additional (TALAF) | No, (Bill Only) | No |
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.
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 following FISH probes:
9p24.1 rearrangement, JAK2 break-apart
t(9;22) or ABL1 amplification, ABL1/BCR
11q23 rearrangement, MLL (KMT2A) break-apart
1p33 rearrangement, TAL1/STIL
t(5;14), TLX3/BCL11B fusion
7q34 rearrangement, TRB break-apart
14q11.2 rearrangement, TRAD break-apart
t(10;11), MLLT10/PICALM fusion
9q34 rearrangement, ABL1 break-apart
5q32 rearrangement, PDGFRB break-apart
When an MLL (KMT2A) rearrangement is identified, reflex testing will be performed to identify the translocation partner. Probes include identification of:
t(4;11)(q21;q23) AFF1/MLL
t(6;11)(q27;q23) MLLT4(AFDN)/MLL
t(9;11)(p22;q23) MLLT3/MLL
t(10;11)(p12;q23) MLLT10/MLL
t(11;19)(q23;p13.1) MLL/ELL
t(11;19)(q23;p13.3) MLL/MLLT1
When a TRAD rearrangement is identified, reflex testing will be performed to identify the translocation partner. Probes include identification of t(10;14)(q24;q11.2) TLX1/TRAD or t(11;14)(p13;q11.2) LMO2/TRAD.
When a TRB rearrangement is identified, reflex testing will be performed to identify the translocation partner. Probes include identification of t(7;10)(q34;q24) TRB/TLX1 or t(7;11)(q34;p13) TRB/LMO2.
For more information see Acute Leukemias of Ambiguous Lineage Testing Algorithm.
Special Instructions
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
Adult ALL (T-cell), FISHSpecimen Type
VariesSpecimen Minimum Volume
Blood: 2 mL
Bone Marrow: 1 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Varies | Ambient (preferred) | |
Refrigerated |
Clinical Information
T-cell acute lymphoblastic leukemia (T-ALL) accounts for approximately 25% of cases of adult lymphoblastic leukemia. Specific genetic abnormalities are identified in most cases of T-ALL, although many of the classic abnormalities are "cryptic" by conventional chromosome studies and must be identified by fluorescence in situ hybridization (FISH) studies. Each of the genetic subgroups is important to detect and can be critical prognostic markers.
A combination of cytogenetic and FISH testing is currently recommended in all pediatric and adult patients to characterize the T-ALL clone for the prognostic genetic subgroups. 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.
Cautions
This test is not approved by the US Food and Drug Administration, and it is best used as an adjunct to clinical and pathologic information.
Fluorescence in situ hybridization (FISH) is not a substitute for conventional chromosome studies because the latter detects chromosome abnormalities associated with other hematological disorders that would go undetected by this FISH panel test.
Bone marrow is the preferred specimen type for this 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).
Day(s) Performed
Monday through Friday
Report Available
7 to 10 daysPerforming Laboratory

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
88271x20, 88275x10, 88291x1-FISH Probe, Analysis, Interpretation; 10 probe sets
88271x2, 88275x1-FISH Probe, Analysis; each additional probe set (if appropriate)