Microsatellite Instability (MSI) HNPCC/Lynch Syndrome by PCR
Also known as: MSIPCR
Use
This test is a screening tool for Lynch syndrome, also known as Hereditary Nonpolyposis Colorectal Cancer (HNPCC). It helps in determining potential eligibility for immunotherapy by identifying microsatellite instability-high (MSI-H) cancers, which often occur in colorectal cancer from individuals with Lynch syndrome and sporadically in some cancers. For specific treatment recommendations, reference is made to the NCCN Clinical Practice Guidelines in Oncology.
Special Instructions
Include a surgical pathology report with the specimen submission. If sending multiple specimens, an order comment or individual orders per sample must accompany them to indicate specimen selection preferences. A Pathologist Block Selection Fee will be applied if using the first option without clarification.
Limitations
The test only detects microsatellite instability at markers BAT-25, BAT-26, MONO-27, NR-21, and NR-24. Instability at other loci will not be detected. The findings must be interpreted in the clinical context and are not definitive for malignancy diagnosis. It does not rule out other genetic disorders associated with colorectal cancer. Genetic counseling is recommended.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 81697-5
- 81698-3
- 81701-5
- 43368-0
- 81699-1
- 81700-7
Result Turnaround Time
10-20 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Collection Instructions
Formalin fix tissue (10 percent neutral buffered formalin) and paraffin embed. Transport tissue block(s) or 10 unstained 5-micron slides (5 tumor and 5 normal epithelial) in a tissue transport kit.
Storage Instructions
Room temperature is preferable, but refrigerated is acceptable. Transport in a cooled container during summer months.
Causes for Rejection
Specimens with less than 25 percent tumor or less than 50 percent normal epithelial tissue. Specimens fixed in fixatives other than 10 percent neutral buffered formalin or bone specimens in non-EDTA decalcifier.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Indefinitely |
| Refrigerated | Indefinitely |
| Frozen | Unacceptable |