Days Set Up
Monday - Thursday
Analytic Time

3 - 10 days

MiChart Code
EWSR1 (22q12) Rearrangement by FISH
Soft Order Code

Test Updated:


FISH for Desmoplastic Small Round Cell Tumor (DSRCT)
FISH for Ewing Sarcoma
FISH for Clear Cell Sarcoma
FISH for Angiomatoid Fibrous Histiocytoma
FISH for Extraskeletal Myxoid Chondrosarcoma
FISH for Myxoid Liposarcoma
FISH for Peripheral Neuroectodermal Tumor

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Test Overview

Test Methodology

Fluorescence In Situ Hybridization (FISH)

Test Usage

This test detects rearrangements involving the EWSR1 gene region (22q12) via fluorescence in situ hybridization (FISH) in formalin-fixed, paraffin-embedded tissue specimens. FISH is performed using a dual color break apart probe (Abbott Molecular) to qualitatively assess for the presence of EWSR1 translocations that occur in soft tissue tumors including Ewing sarcoma/peripheral neuroectodermal tumor, desmoplastic small round cell tumor, clear cell sarcoma, angiomatoid fibrous histiocytoma, extraskeletal myxoid chondrosarcoma, and myxoid liposarcoma. Testing for EWSR1 gene rearrangement may aid in the diagnosis of these tumors.

Reference Range

Interpretive report provided.

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

Specimen Requirements

Collection Offsite

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
Minimum Volume

Billing Information

CPT Code
Pro Fee Code

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.