FISH, Ewing/PNET, EWSR1 (22q12) Rearrangements
Use
Detects rearrangements involving the EWSR1 gene region at chromosome 22q12, supportive of diagnoses including Ewing sarcoma, primitive neuroectodermal tumor (PNET), desmoplastic small round cell tumor, clear cell sarcoma, angiomatoid fibrous histiocytoma, extraskeletal myxoid chondrosarcoma, and myxoid liposarcoma ([mlabs.umich.edu](https://mlabs.umich.edu/tests/ewsr1-22q12-rearrangement-fish?utm_source=openai)).
Special Instructions
Requires formalin-fixed, paraffin‑embedded (FFPE) tumor tissue—either blocks or unstained slides with an H&E‑stained slide. Decalcified or non‑formalin-fixed specimens may yield uninterpretable results ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/overview/35268?utm_source=openai)).
Limitations
This FISH assay detects rearrangements of EWSR1 but does not identify the fusion partner gene ([mlabs.umich.edu](https://mlabs.umich.edu/tests/ewsr1-22q12-rearrangement-fish?utm_source=openai)).
Methodology
Chromosomal / Cytogenetics (FISH)
Biomarkers
Result Turnaround Time
3-10 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Collection Instructions
Submit formalin‑fixed, paraffin‑embedded tumor tissue block or unstained slides (typically 3–4, 4‑5 µm) plus an H&E‑stained slide.
Storage Instructions
Store and ship at room temperature.
Causes for Rejection
Decalcified tissue or alternative fixatives may result in failed testing.