Test Id : TALMF

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.

This test is performed using client-specified FISH probes and is not intended as a panel test. Specific probes must be listed in the probe request field. Reflex probes can be performed when appropriate if specified in the order request field.

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 PDGFRB rearrangement, request probe PDGFRB break-apart

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

t(6;7)(q23;q34) or TRB:MYB 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

-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.

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

At diagnosis, conventional cytogenetic studies (CHRBM / Chromosome Analysis, Hematologic Disorders, Bone Marrow) and a complete T-ALL FISH panel (either TALAF or TALFP) should be performed.

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 TALFP / Pediatric T-Lymphoblastic Leukemia/Lymphoma panel, FISH, 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.

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 TALFP / Pediatric T-Lymphoblastic Leukemia/Lymphoma panel, FISH, Varies? should be performed, depending on patient's age. If there is limited specimen available, only fluorescence in situ hybridization testing will be performed.

Advise Express Mail or equivalent if not on courier service.

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.

Submit only 1 of the following specimens:

Preferred

Specimen Type: Bone marrow

Container/Tube:

Preferred: Yellow top (ACD)

Acceptable: Green top (sodium 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 (sodium 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.

If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.

Bone marrow: 1 mL; Whole blood: 2 mL

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

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

This test should not be used to screen for residual T-ALL

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.

This test is performed using client-specified FISH probes and is not intended as a panel test. Specific probes must be listed in the probe request field. Reflex probes can be performed when appropriate if specified in the order request field.

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 PDGFRB rearrangement, request probe PDGFRB break-apart

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

t(6;7)(q23;q34) or TRB:MYB 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

-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.

Acute lymphoblastic leukemia (ALL) accounts for approximately 70% of all childhood leukemia cases (aged 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

An interpretive report will be provided.

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.

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.

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 in a targeted T-cell acute lymphoblastic leukemia/lymphoma FISH test. 

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.

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;17:738-745

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

This test is performed using commercially available and laboratory-developed probes. Rearrangements involving TAL1/STIL, PDGFRB, TRB, JAK2, ABL1, KMT2A, and TRA 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 KMT2A, TRB, or TRA genes are detected. Amplification of the ABL1 gene region is detected using a D-FISH probe strategy to enumerate copies of the ABL1 probe. 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)

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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.

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

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