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Test Code 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

Method Name

Fluorescence In Situ Hybridization (FISH)

Reporting Name

Adult ALL (T-cell), 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

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.

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

88271x20, 88275x10, 88291x1-FISH Probe, Analysis, Interpretation; 10 probe sets

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

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.