Test Name

EWSR1 (22q12) GENE REARRANGEMENT BY FISH

Aliases

EWING/PNET REARRANGEMENTS, EWING SARCOMA BREAKPOINT REGION 1, EWING SARCOMA GENE REARRANGEMENT, PERIPHERAL NEUROECTODERMAL TUMOR GENE, ANGIOMATOID FIBROUS HISTIOCYTOMA GENE, CLEAR CELL SARCOMA GENE, DESMOPLASTIC SMALL ROUND CELL TUMOR GENE

Abbreviations

EWSR1 FISH, EWSR1 FUSION ASSAY, EWSR1 TRANSLOCATION TEST

Test Classification

INDIVIDUAL

Department

MOLECULAR PATHOLOGY

Sub Department

ONCOLOGY

TAT Category

ELAPSED (CONTINUOUS) TIME

Estimated TAT

17

TAT Units

DAYS

Test Requirements

Labeled tumor positive formalin-fixed, paraffin-embedded (FFPE) block with adequate residual tissue. Transport at room temperature (avoid excessive heat). Clinical history including exact tissue source/ anatomic site and original H&E report and if applicable immunohistochemical (IHC) findings must be provided.

Clinical Utility

Detects EWSR1 gene rearrangements diagnostic for Ewing sarcoma family tumors (ESFT), including Ewing sarcoma and peripheral primitive neuroectodermal tumor (PNET). Also identifies EWSR1 fusions in other malignancies: clear cell sarcoma (EWSR1/ATF1), desmoplastic small round cell tumor (EWSR1/WT1), extraskeletal myxoid chondrosarcoma (EWSR1/NR4A3), and angiomatoid fibrous histiocytoma. It does not identify the specific fusion partner. Applications: 1. Confirms diagnosis in small round blue cell tumors 2. Differentiates Ewing sarcoma family tumors from mimics. 3. Guides treatment decisions 4. Prognostic information Present in ~85-90% of Ewing sarcoma cases.

Last Review

26th Feb 2026