ARUP's Laboratory Test Directory

0049335: EWSR1 Break Apart Rearrangement by FISH

Test Mnemonic: EWSR1
Methodology: Fluorescence in situ Hybridization

Performed: Weekly

Reported: 4-12 days

Specimen Required:  
Collect: Tumor tissue.

Transport: Paraffin-embedded, formalin-fixed tissue block at  20-25°C. Protect paraffin block from excessive heat. Ship in cooled container during summer months. Include surgical pathology report.

Remarks: Only tissue that is clearly carcinoma (established by histopathologic criteria) should be sent.

Unacceptable Conditions: Samples fixed/processed in alternate fixatives (alcohol, Prefer®,etc.) should not be submitted. No tumor in tissue or frozen tissue.

Stability: Paraffin block: Ambient: Indefinitely; Refrigerated: Indefinitely; Frozen: Unacceptable

Reference Interval:
Greater than or equal to 25%: Positive for EWSR1 gene translocation
Less than 25%: Negative for EWSR1 gene translocation

Interpretive Data:
Current literature suggests that the rearrangement of this gene is of diagnostic value for the evaluation of Ewing sarcoma.

Break-apart translocations in 25% or more of the cells counted are considered positive for an EWSR1 gene translocation. Break-apart translocations in less than 25% of the cells indicate the neoplasm is negative for an EWSR1 gene translocation.

Translocations in the EWSR1 gene are indicative that the tumor belongs to the Ewing's family of neoplasms.

Please refer to Statement A in the Compliance Statements section in the front of the Laboratory Test Directory.



CPT Code(s):
88368 x2