Mismatch Repair (MMR) Protein Immunohistochemistry Only, Tumor
Use
This test is useful for evaluating tumor tissue to identify patients at risk for hereditary nonpolyposis colon cancer, also known as Lynch syndrome. Individuals with Lynch syndrome have a germline mutation in one of several DNA mismatch repair genes, often leading to colorectal and other cancers. The test assesses the loss of protein expression of MLH1, MSH2, MSH6, and PMS2 within tumor tissues, providing insight into which genes may harbor potentially causative mutations, which is a crucial step in the diagnosis and management of Lynch syndrome.
Special Instructions
A pathology report with patient name, block number, tissue collection date, and source of tissue must accompany the specimen for testing. MLH1, MSH2, MSH6, and PMS2 immunostains will always be performed and billed separately at an additional charge.
Limitations
While immunohistochemistry can determine the retention or loss of protein expression of MMR proteins, it does not distinguish between somatic and germline mutations. The results should be interpreted alongside clinical findings as well as family and laboratory data. It is also possible to have loss of protein expression in sporadic cancers. Additional genetic testing is recommended for confirmation.
New York Approved
Methodology
Immunoassay (IHC)
Biomarkers
LOINC Codes
- 50397-9
- 59465-5
- 31208-2
- 80398-1
- 81691-8
- 81692-6
- 81693-4
- 81694-2
Result Turnaround Time
5-8 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Container
Formalin-fixed, paraffin-embedded tissue block or slides
Collection Instructions
Submit a formalin-fixed, paraffin-embedded tissue block with acceptable amount of tumor tissue, or 1 slide stained with hematoxylin and eosin along with 10 unstained slides.
Storage Instructions
Room temperature preferred for ambient transport; refrigerated accepted.
Causes for Rejection
All specimens will be evaluated for test suitability.