Update Type: Test Resumed
Test Updated: 09/28/2023
Test Overview
Test Methodology

Fluorescence In Situ Hybridization (FISH)

Test Usage

This test detects amplification of the MDM2 gene region (12q15) via fluorescence in situ hybridization (FISH) in formalin-fixed, paraffin-embedded tissue specimens. FISH is performed using Vysis (Abbott Molecular, Inc.) probes to the MDM2 locus (12q15) and the chromosome 12 centromere (CEP12). MDM2 amplification is present in most cases of atypical lipomatous tumor/well-differentiated liposarcoma and most cases of dedifferentiated liposarcoma. MDM2 amplification is not seen in benign lipomatous tumors. Testing for MDM2 amplification may aid in the diagnosis and classification of these tumors.

Reference Range *

Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

Amplification may not be detected if sufficient liposarcomatous tissue is not present within the submitted block. Selection of the appropriate block may be problematic given the histologic similarity between atypical lipomatous tumor/well-differentiated liposarcoma and adjacent benign adipose tissue.

Test Details
Days Set Up
Monday - Thursday
Analytic Time

3 - 10 days

Soft Order Code
MiChart Code
MDM2 Amplification by FISH
  • 12q15
  • MMDM2
  • Chromosome 12 centromere (CEP12)
  • Liposarcoma
Molecular Diagnostics
Molecular Diagnostics
Specimen Requirements
Collection Instructions

A formalin-fixed, paraffin-embedded tissue block containing sufficient neoplastic cells is preferred. Unstained slides (3, 4-micron slides) with associated H&E stained slide are also acceptable. Decalcified tissue or other fixatives will be accepted and the assay attempted, however these may result in failed testing due to degraded nucleic acid. Both blocks and slides should be stored at room temperature.

Normal Volume
Formalin-fixed, paraffin-embedded tissue
Additional Information

By ordering this test the clinician acknowledges that informed consent has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test includes pathologist interpretation of results billed as a separate additional charge. This test is not available without interpretation.

CPT Code
Fee Code
Pro Fee CPT
NY State Approved