RET Gene Rearrangements by FISH

Casandra

Casandra Test Code AR90007Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 3001312CPT Code 88366

RET Gene Rearrangements by FISH

Also known as: RET_FISH

Clinical Use

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Use

This test is used to detect RET gene rearrangements in solid tumors, specifically in non-small cell lung cancer and thyroid cancer. RET rearrangements occur in approximately 1-2% of lung adenocarcinomas and 10-20% of papillary thyroid carcinomas. Detecting these rearrangements can aid in the diagnostic classification of diseases and predicting tumor response to targeted therapies.

Special Instructions

Include the surgical pathology report with specimen submission. If multiple specimens (blocks or slides) are sent, indicate if the pathologist should choose the specimen most appropriate for testing, which may result in a Pathologist Block Selection Fee.

Limitations

The test detects rearrangements involving the RET gene but does not identify the translocation partner or variant. It does not detect cryptic rearrangements and is intended for specific solid tumor types. Viability is dependent on sufficient tumor tissue being present in the specimen.

Test Details

New York Approved

Methodology

Chromosomal / Cytogenetics (FISH)

Biomarkers

LOINC Codes

Result Codes

81304-8
78236-7

Result Turnaround Time

3-7 days

Specimen

Tissue (FFPE)

Volume

Not provided

Minimum Volume

2 slides

Container

Paraffin block or slides

Collection Instructions

Formalin fix (10 percent neutral buffered formalin) and paraffin embed tumor tissue. Transport tissue block or 4 unstained, consecutively cut, 5-micron thick sections, mounted on positively charged glass slides. Protect paraffin block and/or slides from excessive heat.

Storage Instructions

Room temperature. Also acceptable: Refrigerated.

Causes for Rejection

Paraffin block with no tumor tissue remaining. Specimens fixed in any fixative other than 10 percent neutral buffered formalin. Decalcified specimens.