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Test Code MSTF Myeloid Sarcoma, FISH, Tissue

Useful For

Supporting the diagnosis of myeloid sarcoma when coordinated with a surgical pathology consultation

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
_I099 Interphases, 25-99 No, (Bill Only) No
_I300 Interphases, >=100 No, (Bill Only) No
_IL25 Interphases, <25 No, (Bill Only) No
_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

Testing Algorithm

This test does not include a pathology consult. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered, and the appropriate fluorescence in situ hybridization (FISH) test will be performed at an additional charge.

 

This test includes a charge for application of the first probe set (2 FISH probes) and professional interpretation of results. Additional charges will be incurred for all reflex probes 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.

 

The test panel includes analysis for the disease-associated abnormalities using the probes listed below:

t(8;21), [M2], RUNX1T1/RUNX1

t(11q23;var), [M0-M7], MLL (KMT2A)

inv(16), [M4, Eos], MYH11/CBFB

t(15;17), [M3], PML/RARA

t(9;22), BCR/ABL1

 

If the patient is being treated for known abnormalities, indicate which probes should be used.

 

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.

Method Name

Fluorescence In Situ Hybridization (FISH)

Reporting Name

Myeloid Sarcoma, FISH, Ts

Specimen Type

Tissue


Shipping Instructions


Advise Express Mail or equivalent if not on courier service.



Necessary Information


A reason for referral and pathology report are required in order for testing to be performed. Send information with specimen. Acceptable pathology reports include working drafts, preliminary pathology or surgical pathology reports.



Specimen Required


Specimen Type: Tissue

Preferred: Tissue block

Collection Instructions: Submit a formalin-fixed, paraffin-embedded tumor tissue block. Blocks prepared with alternative fixation methods may be acceptable; provide fixation method used.

Acceptable: Slides

Collection Instructions: For each probe set ordered, 2 consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.


Specimen Minimum Volume

For each probe set ordered, 2 consecutive, unstained, 5 micron-thick sections placed on positively charged slides.
Include 1 hematoxylin and eosin (H and E)-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

Myeloid sarcomas are tumors made up of myeloblasts or immature myeloid cells that occur in extramedullary sites or in bone. They can occur concurrently with acute or chronic myeloid leukemia (AML or CML) or may precede the leukemia or other myeloid neoplasms. They may also be the initial manifestation of relapse of a previously treated primary AML in remission. Due to this extramedullary presentation, the bone marrow may have a low number of myeloblasts due to a lack of bone marrow involvement.

 

The most common abnormalities seen in myeloid sarcomas are fusion of RUNX1T1/RUNX1 (t[8;21][q22;q22]), PML/RARA (t[15;17][q24;q21]), BCR/ABL1 (t[9;22][q34;q11.2]), inversion of MYH11/CBFB (inv[16][q13.1q22]), and rearrangements of MLL (KMT2A; t[11q23;var]).

 

In general, AML patients with an inv(16), t(8;21), t(9;22), or t(15;17) have a favorable prognosis, while AML patients with a rearrangement of t(11q23) have an unfavorable prognosis. Thus, the detection of these abnormalities in an extramedullary presentation of AML can be prognostically important.

Reference Values

An interpretive report will be provided.

Interpretation

A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal reference range for a given probe set.

 

A positive result supports the diagnosis of a myeloid sarcoma.

 

A negative result does not exclude the diagnosis of a myeloid sarcoma.

Supportive Data

Fluorescence in situ hybridization (FISH) analysis was performed on 25 noncancerous formalin-fixed paraffin-embedded tissue control specimens with the results used to generate the normal cutoff value for each probe set. A retrospective data review of FISH analysis performed on myeloid sarcomas identified 3 cases with RUNX1T1/RUNX1 fusion, 1 case with BCR/ABL1 fusion, 3 cases with rearrangement of MLL (KMT2A), 4 cases with PML/RARA fusion, and 4 cases with MYH11/CBFB fusion.

Method Description

This test is performed using a commercially available MLL (KMT2A) dual-color break-apart strategy probe (BAP), a laboratory developed MYH11/CBFB dual-color, dual-fusion (D-FISH) strategy probe, and commercially available RUNX1T1/RUNX1, BCR/ABL1, and PML/RARA D-FISH strategy probes. Formalin-fixed paraffin-embedded tissues are cut at 5 microns and mounted on positively charged glass slides. The selection of tissue and the identification of target areas on the hematoxylin and eosin (H and E)-stained slide are performed by a pathologist. Using the H and E-stained slide as a reference, target areas are etched with a diamond-tipped etcher on the back of the unstained slide to be assayed. The probe is hybridized to the appropriate target area and 2 technologists each analyze 50 interphase nuclei (100 total for each probe set) with the results expressed as the percent of abnormal nuclei.(Unpublished Mayo method)

Day(s) Performed

Monday through Friday

Report Available

7 to 10 days

Specimen Retention Time

Slides and H and E used for analysis are retained by the laboratory in accordance to CAP and NYS requirements. Client provided paraffin blocks and extra unstained slides (if provided) will be returned after testing is complete.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

88291

88271 x 2 (if appropriate)

88271 x 2 (if appropriate)

88271 (if appropriate)

88271 x 2 (if appropriate)

88271 x 3 (if appropriate)

88274 w/modifier 52 (if appropriate)

88274 (if appropriate)

88275 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MSTF Myeloid Sarcoma, FISH, Ts In Process

 

Result ID Test Result Name Result LOINC Value
52084 Result Summary 50397-9
52086 Interpretation 69965-2
52085 Result Table 93356-4
54576 Result 62356-1
CG735 Reason for Referral 42349-1
CG736 Specimen 31208-2
52087 Source 31208-2
52088 Tissue ID 80398-1
52089 Method 85069-3
55121 Additional Information 48767-8
53839 Disclaimer 62364-5
52090 Released By 18771-6

Forms

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

Cautions

Paraffin-embedded tissues that have been decalcified may not be successful for fluorescence in situ hybridization (FISH) analysis. FISH studies will be attempted if sufficient tumor is present for analysis. However, if no FISH signals are observed post-hybridization, the case will be released indicating a lack of FISH results.