EWSR1 (22q12) Gene Rearrangement by FISH

Casandra

Casandra Test Code AR26793Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 3001305CPT Code 88366

EWSR1 (22q12) Gene Rearrangement by FISH

Also known as: EWSR1_FISH

Clinical Use

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Use

This test is used to diagnose members of the Ewing sarcoma family of tumors (ESFT) by detecting rearrangements involving the EWSR1 gene. However, it does not identify specific translocation partner genes. EWSR1 rearrangements are useful markers for diagnosing Ewing family of tumors and are also found in other tumors including clear cell sarcoma, desmoplastic small round cell tumor, extraskeletal myxoid chondrosarcoma, myxoid liposarcoma, rhabdomyosarcoma, and angiomatoid fibrous histiocytoma. Thus, correlation with histopathologic and clinical findings is essential for complete interpretation.

Special Instructions

Formalin fix (10 percent neutral buffered formalin) and paraffin embed tissue. Ship tissue block or 5 unstained positively charged slides in a kit from ARUP supply or contact ARUP Client Services. Multiple specimens require a pathologist determination or individual orders. Pathologist Block Selection Fee applies if ARUP selects the specimen.

Limitations

This test can detect EWSR1 gene rearrangements in patients with EWSR1 rearranged tumors but cannot identify the translocation partner. The assay does not detect very rare cryptic rearrangements. An abnormal signal pattern in 25% or more of tumor cells is considered positive. No approvals from U.S. Food and Drug Administration but performed in a CLIA-certified laboratory for clinical purposes.

Test Details

New York Approved