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Alternative Name
Ewing Sarcoma
Test Description

Probes: EWSR1 (22q12)
Disease(s): Ewing sarcoma, primitive neuroectodermal tumor (PNET)

Clinical Significance

This EWSR1 break-apart FISH test is for diagnostic confirmation and classification of tumors diagnosed or suspected to be Ewing sarcoma/primitive neuroectodermal tumor (ES / PNET) based on morphology or immunohistologic studies. EWSR1 translocations are the hallmark and pathognomic molecular findings of Ewing sarcoma (almost all ES) and "Ewing-like sarcoma". EWSR1 rearrangement partners will not be identified by this FISH test. For that purpose, please see the NGS Sarcoma Fusion Profile which may be ordered separately or as a reflex after positive FISH.

Specimen Requirements
  • Bone marrow aspirate:  N/A
  • Peripheral blood: N/A
  • Fresh, unfixed tissue: N/A.
  • Fluids: N/A
  • Paraffin block: Send paraffin block. Also send circled H&E slide for tech-only (required)
  • Cut slides: H&E slide (required) plus 4 unstained slides cut at 4-5 microns. Circle H&E slide for tech-only
Storage and Transportation

Refrigerate specimen. Do not freeze. Use cold pack for transport, making sure cold pack is not in direct contact with specimen.

CPT Code(s)*
88377x1 manual or 88374x1 automated
New York Approved
Level of Service
Turnaround Time

4 days

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.