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HelpTest Code MDM2F MDM2 (12q15) Amplification, Well-Differentiated Liposarcoma/Atypical Lipomatous Tumor, FISH, Tissue
Useful For
Identifying the presence or absence of MDM2 amplification
Aiding in the diagnosis of many neoplasms, including, but not limited to, well-differentiated liposarcoma, atypical lipomatous tumor, dedifferentiated liposarcoma, parosteal osteosarcoma and central low-grade osteosarcoma associated with MDM2 amplification at 12q15 when used conjunction with an anatomic pathology assessment
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| _PBCT | Probe, +2 | 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 |
| _IL25 | Interphases, <25 | No, (Bill Only) | No |
| _I099 | Interphases, 25-99 | No, (Bill Only) | No |
| _I300 | Interphases, >=100 | No, (Bill Only) | No |
Testing Algorithm
This test includes a charge for probe application, analysis, and professional interpretation of results for one probe set (2 individual fluorescence in situ hybridization probes). Analysis charges are based on the number of cells analyzed per probe. No analysis charges apply if there are insufficient representative cells for evaluation.
Appropriate ancillary probes may be performed at the consultant's 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
MDM2 (12q15) Amp, FISH, TsSpecimen Type
TissueOrdering Guidance
This test does not include a pathology consultation. If a pathology consultation is requested, order PATHC / Pathology Consultation, and appropriate testing will be added at the discretion of the pathologist and performed at an additional charge.
Multiple oncology (cancer) gene panels are also available. For more information see Hematology, Oncology, and Hereditary Test Selection Guide.
Additional Testing Requirements
To resolve atypical fluorescence in situ hybridization results, confirmation testing by microarray is available; order CMAPT / Chromosomal Microarray, Tumor, Formalin-Fixed Paraffin-Embedded.
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
1. A pathology report is required for testing to be performed. If not provided, appropriate testing and interpretation may be compromised or delayed. Acceptable pathology reports include working drafts, preliminary pathology, or surgical pathology reports.
2. The following information must be included in the report provided:
-Patient name
-Block number - must be on all blocks, slides, and paperwork
-Collection date
-Tissue source
3. 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.
Specimen Required
Submit only 1 of the following specimens:
Preferred:
Specimen Type: Tissue block (fresh tissue is not acceptable)
Collection Instructions:
1. Submit a formalin-fixed, paraffin-embedded tumor tissue block.
2. Blocks prepared with alternative fixation methods (eg, Prefer, Bouin's) will be attempted but are less favorable for successful results. Provide fixation method used.
Additional Information:
1. Paraffin-embedded specimens can be from any anatomic location (skin, soft tissue, lymph node, etc).
2. Decalcified paraffin-embedded specimens will have testing attempted; however, the success rate is approximately 50%. Testing may be canceled if sufficient tumor tissue is not present.
3. Submitted fresh tissue specimens will be canceled upon receipt. If only fresh tissue is available, embed in paraffin prior to sending.
Acceptable:
Specimen Type: Tissue slides
Slides: 1 Hematoxylin and eosin-stained and 4 unstained
Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 4 consecutive unstained, positively charged, unbaked slides with 5-micron-thick sections of the tumor tissue.
Additional Information: Broken or cracked unstained slides will be rejected. Stained slides that were broken and repaired (ie, double mounted) at the client site will not be rejected, as, in most cases, they can still be reviewed under the microscope. However, due to the double mounting, digital scanning cannot be performed.
Specimen Minimum Volume
Slides: 1 Hematoxylin and eosin-stained and 2 unstained
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Tissue | Ambient (preferred) | |
| Refrigerated | ||
Reject Due To
| Broken or cracked unstained slides | Reject |
| Broken or cracked stained slides that cannot be repaired | Reject |
Clinical Information
Differential diagnosis of well-differentiated liposarcoma/atypical lipomatous tumor:
The histological discrimination of well-differentiated liposarcoma/atypical lipomatous tumor (WDL/ALT) from lipoma can be diagnostically challenging. Amplification of genomic material derived from the chromosome band 12q13-15, which contains several genes, including MDM2, has been shown to be a recurrent finding in most WDL/ALT. Therefore, the detection of MDM2 gene amplification by fluorescence in situ hybridization (FISH) may be a useful adjunct to support a diagnosis of WDL/ALT in the proper histopathologic context.
Differential diagnosis of osteosarcoma:
The histological discrimination of parosteal or low-grade central osteosarcoma from other morphologically similar, but clinically distinct, entities can be difficult. Amplification of genomic material derived from the chromosome band 12q13-15, which contains several genes, including MDM2, has been shown to be a recurrent finding in a large proportion (67%-100%) of parosteal and central low-grade osteosarcomas. Therefore, the detection of MDM2 gene amplification by FISH may be a useful adjunct to support a diagnosis of low-grade central or parosteal osteosarcoma in the proper histopathologic context. Amplifications of 12q13-15 (including MDM2) are less common in conventional high-grade osteosarcoma, estimated to occur in approximately 5% to 10% of tumors.
Reference Values
An interpretive report will be provided.
Interpretation
MDM2 will be clinically interpreted as positive, negative, or equivocal.
A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal reference range for the MDM2 probe set.
Differential diagnosis of well-differentiated liposarcoma/atypical lipomatous tumor:
A positive result is consistent with amplification of the MDM2 gene locus (12q15) and, in the proper clinical and pathologic context, may support the diagnosis of well-differentiated liposarcoma/atypical lipomatous tumor (WDL/ALT). MDM2 amplification may be seen in other neoplasms and is not diagnostic in isolation. Clinical and pathologic correlation is required.
A negative result is consistent with absence of amplification of the MDM2 gene locus (12q15) but does not exclude the diagnosis of WDL/ALT. Clinical and pathologic correlation is required.
Differential diagnosis of osteosarcoma:
A positive result is consistent with amplification of the MDM2 gene locus (12q15) and, in the proper clinical and pathologic context, may support the diagnosis of parosteal osteosarcoma or low-grade central osteosarcoma. MDM2 amplification may be seen in other neoplasms and is not diagnostic in isolation. Clinical and pathologic correlation is required.
A negative result is consistent with absence of amplification of the MDM2 gene locus (12q15) but does not exclude the diagnosis of low-grade central osteosarcoma or parosteal osteosarcoma. Clinical and pathologic correlation is required.
A negative result does not exclude the presence of a neoplastic disorder.
Cautions
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.
This test is intended to be used for diagnostic purposes in well-differentiated liposarcoma/atypical lipomatous tumors and parosteal osteosarcomas.
This fluorescence in situ hybridization (FISH) assay does not rule out other chromosome abnormalities.
Fixatives other than formalin (eg, Prefer, Bouin's) may not be successful for FISH assays. Non-formalin fixed specimens will not be rejected.
Paraffin-embedded tissues that have been decalcified may not be successful for FISH analysis. The success rate of FISH studies on decalcified tissue is approximately 50%, but FISH will be attempted if sufficient tumor is present for analysis.
Fluorescence in situ hybridization studies will be attempted if sufficient tumor is present for analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing if insufficient tissue/tumor is available for testing.
If no FISH signal or a lack of sufficient tumor tissue is observed post-hybridization, the case will be reported indicating a lack of FISH results.
Clinical Reference
1. Erickson-Johnson MR, Seys AR, Roth CW, et al. Carboxypeptidase M: a biomarker for the discrimination of well-differentiated liposarcoma from lipoma. Mod Pathol. 2009;22(12):1541-1547
2. Jacob E, Erickson-Johnson MR, Wang X, et al. Assessment of MDM2 amplification using fluorescence in situ hybridization on paraffin-embedded tissue discriminates atypical lipomatous tumors from lipomas. Mod Pathol. 2006;19(13A):45
3. He X, Pang Z, Zhang X, et al. Consistent amplification of FRS2 and MDM2 in low-grade osteosarcoma: A genetic study of 22 cases with clinicopathologic analysis. Am J Surg Pathol. 2018;42(9):1143-1155
4. Duhamel LA, Ye H, Halai D, et al. Frequency of Mouse Double Minute 2 (MDM2) and Mouse Double Minute 4 (MDM4) amplification in parosteal and conventional osteosarcoma subtypes. Histopathology. 2012;60(2):357-359
5. Dujardin F, Binh MB, Bouvier C, et al. MDM2 and CDK4 immunohistochemistry is a valuable tool in the differential diagnosis of low-grade osteosarcomas and other primary fibro-osseous lesions of the bone. Mod Pathol. 2011;24(5):624-637
6. WHO Classification of Tumours Editorial Board. Soft Tissue and Bone. 5th ed. IARC; 2020. World Health Organization Classification of Tumours. Vol 3
Method Description
This test is performed using a commercially available enumeration strategy MDM2 and chromosome 12 centromere (D12Z3) fluorescence in situ hybridization probe set. Paraffin-embedded tissue samples 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 engraving tool on the back of the unstained slide to be assayed. The probe set is hybridized to the appropriate target areas, and 2 technologists each analyze 30 interphase nuclei (60 total) with the results expressed as a ratio MDM2:D12Z3 signals.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
7 to 10 daysSpecimen Retention Time
Slides and H and E used for analysis are retained by the laboratory in accordance with regulatory requirements. Client provided paraffin blocks and extra unstained slides will be returned after testing is complete.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
88271x2, 88291-DNA probe, each (first probe set), Interpretation and report
88271x2-DNA probe, each; each additional probe set (if appropriate)
88271-DNA probe, each; coverage for sets containing 3 probes (if appropriate)
88271x2-DNA probe, each; coverage for sets containing 4 probes (if appropriate)
88271x3-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)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| MDM2F | MDM2 (12q15) Amp, FISH, Ts | 93808-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 54681 | Result Summary | 50397-9 |
| 54684 | Interpretation | 69965-2 |
| 54683 | Result | 62356-1 |
| CG929 | Reason For Referral | 42349-1 |
| 54917 | Specimen | 31208-2 |
| 54686 | Source | 31208-2 |
| 54687 | Tissue ID | 80398-1 |
| 55132 | Method | 85069-3 |
| 55133 | Additional Information | 48767-8 |
| 53396 | Disclaimer | 62364-5 |
| 54688 | Released By | 19139-5 |
NY State Approved
YesForms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.