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HelpTest Code CILPF Congenital Infantile Leukemia, FISH, Tissue
Ordering Guidance
This test is only performed on specimens from patients with acute leukemia who are 18 months of age or younger.
For testing bone marrow or blood specimens from patients with congenital infantile leukemia, order CILDF / Congenital Infantile Leukemia, Diagnostic FISH, Varies.
If this test is ordered on a patient older than 18 months of age and the reason for testing is B-cell or T-cell acute lymphocytic leukemia (B-ALL or T-ALL), this test will be canceled and automatically reordered by the laboratory as BLBLF / B-Cell Acute Lymphoblastic Leukemia/Lymphoma, FISH, Tissue or TLBLF / T-Cell Acute Lymphoblastic Leukemia/Lymphoma, FISH, Tissue.
If this test is ordered on a patient older than 18 months of age and the reason for testing is acute myeloid leukemia (AML), this test will be canceled and automatically reordered by the laboratory as MSTF / Myeloid Sarcoma, FISH, Tissue.
This test does not include a pathology consult. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered and the appropriate FISH test will be ordered and performed at an additional charge.
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
A reason for testing and pathology report are required for testing to be performed. Send information with specimen. Acceptable pathology reports include working drafts, preliminary pathology or surgical pathology reports. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed. If this information is not provided, an appropriate indication for testing may be entered by Mayo Clinic Laboratories.
Specimen Required
Submit only 1 of the following specimens:
Specimen Type: Tissue
Preferred: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded (FFPE) tumor tissue block. Blocks prepared with alternative fixation methods may be acceptable; provide fixation method used.
Additional Information:
1. The paraffin embedded specimen can be from any anatomic location (skin, soft tissue, lymph node, etc.).
2. Bone specimens that have been decalcified will be attempted for FISH, with a success rate of approximately 50%.
Acceptable: Slides
Collection Instructions: 20 Consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.
Useful For
Detecting a neoplastic clone associated with the common chromosome abnormalities and classic rearrangements seen in infant patients with leukemia using tissue specimens
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| _PADD | Probe, +1 | No, (Bill Only) | No |
| _PB02 | Probe, +2 | No, (Bill Only) | No |
| _PB03 | Probe, +3 | No, (Bill Only) | No |
| _PBCT | Probe, +2 | No, (Bill Only) | No |
| _IL25 | Interphases, <25 | No, (Bill Only) | No |
| _I099 | Interphases, 25-99 | No, (Bill Only) | No |
| _I300 | Interphases, >=100 | No, (Bill Only) | No |
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
Congenital Infantile Leuk, FISH, TsSpecimen Type
TissueSpecimen Minimum Volume
15 consecutive, unstained, 5-micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Tissue | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Clinical Information
While pediatric leukemia is the most common malignancy affecting children, acute leukemia occuring prior to the age of 18 months (infant leukemia) or occuring within the first 3 months of life (congenital leukemia) are relatively rare in occurrence. The incidence of congenital and infant acute leukemia cases (through 12 months of age) is estimated at only 30 to 40 cases/million/year, with the majority comprising infant cases. Nearly all cases of congenital and infant acute leukemia represent either acute myeloid leukemia (AML) or B-cell acute lymphocytic leukemia/lymphoblastic lymphoma (B-ALL/LBL) with only very rare cases of T-cell-ALL/LBL identified in this age group.
Characteristic genetic abnormalities have been identified in both the congenital acute leukemia and infant acute leukemia setting, each with uniquely associated clinical-pathologic correlations. Rare but important patients with KAT6A/CREBBP translocations and congenital acute leukemia have been described with spontaneously remitting AML despite the lack of therapeutic intervention. In addition, transient abnormal myelopoiesis associated with Down syndrome is another common manifestation encountered in the neonatal setting that can be associated with the development of frank acute leukemia. In contrast, nearly 80% of infant acute leukemia cases are associated with MLL(KMT2A) translocation events with varying percentages of translocation partners based on an AML versus B-ALL/LBL presentation.
Due to the underlying genetic heterogeneity associated with both congenital and infant leukemia and the important prognostic, diagnostic, and occasional therapeutic targets identified, appropriate genetic characterization of this uncommon acute leukemia presentation is critical. These thorough fluorescence in situ hybridization (FISH) panels have been developed by Mayo Clinic Laboratories to interrogate the more common AML and B-ALL abnormalities associated with both congenital and infant acute leukemias. These FISH probes have been validated both in bone marrow/blood CILDF / Congenital Infantile Leukemia, Diagnostic FISH, Varies and in paraffin CILPF / Congenital Infantile Leukemia, FISH, Tissuesince a significant minority of these patient’s present clinically with isolated extramedullary (tissue) manifestations (ie, myeloid sarcoma).
Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Friday
Report Available
7 to 10 daysPerforming 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
88271 x2, 88291-DNA probe, each (first probe set), interpretation and report
88271 x2-DNA probe, each; each additional probe set (if appropriate)
88271-DNA probe, each; coverage for sets containing 3 probes (if appropriate)
88271 x 2-DNA probe, each; coverage for sets containing 4 probes (if appropriate)
88271 x 3-DNA probe, each; coverage for sets containing 5 probes (if appropriate)
88274 w/modifier 52-Interphase in situ hybridization, <25 cells, each probe set (if appropriate)
88274-Interphase in situ hybridization, 25 to 99 cells, each probe set (if appropriate)
88275-Interphase in situ hybridization, 100 to 300 cells, each probe set (if appropriate)
Forms
If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.