Ordering Guidance

This test is only performed on specimens from patients with T-cell acute lymphoblastic leukemia (T-ALL) who are 30 years or younger.

This test is intended for instances when the entire T-ALL fluorescence in situ hybridization (FISH) panel is needed for a pediatric 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) is 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 older than 31 years of age or older, this test will be canceled and automatically reordered by the laboratory as TALAF/ T-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), FISH, Adult, 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 BALPF / B-Cell Acute Lymphoblastic Leukemia/Lymphoma (ALL), Pediatric, FISH, Varies testing is ordered concurrently with this test, the laboratory may cancel TALPF 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 TALPF, the same reflex testing will be performed in the TALMF. This cancellation is necessary to avoid duplicate testing. Probes for CDKN2A/D9Z1, ABL1/BCR, break-apart MLL, TP53/D17Z1 will still be performed as part of the pediatric B-ALL FISH panel.

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 leukemia/lymphoma (T-LBL), order TLBLF / T-Cell 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 FISH 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.