Mismatch Repair by Immunohistochemistry, with Interpretation
Ordering Recommendation
First-line screening test for Lynch syndrome.
New York DOH Approval Status
Specimen Required
Tumor tissue.
Formalin fix (10 percent neutral buffered formalin is preferred) and paraffin embed specimen. If sending precut slides, do not oven bake. Transport tissue block or 10 unstained (3-5 micron thick sections), positively charged slides in a tissue transport kit (ARUP supply #47808) available online through eSupply using ARUP Connect™ or contact ARUP Client Services at (800) 522-2787.(Min: 5 slides). Protect paraffin block and/or slides from excessive heat.
Room temperature or refrigerated. Ship in cooled container during summer months.
Paraffin block with no tumor tissue remaining. Specimens fixed in any fixative other than 10 percent neutral buffered formalin. Decalcified specimens.
Only tissue that is clearly carcinoma (established by histological criteria) should be tested. Include surgical pathology report. Submit electronic request. If you do not have electronic ordering capability, use an ARUP requisition form complete with an ARUP client number. For additional technical details, please contact ARUP Client Services at (800) 522-2787.
If multiple specimens (blocks or slides) are sent to ARUP, they must be accompanied by one of the following: an order comment indicating that the ARUP pathologist should choose the specimen most appropriate for testing (e.g., "Choose best block"), or individual orders for each sample submitted. A Pathologist Block Selection Fee (ARUP test code 3002076) will be added to orders that utilize the first option. If multiple specimens are sent to ARUP without a request for pathologist block/slide selection or individual orders, they will be held until clarification is provided.
Ambient: Indefinitely; Refrigerated: Indefinitely; Frozen: Unacceptable
Methodology
Qualitative Immunohistochemistry
Performed
Tue-Sat
Reported
1-5 days
Reference Interval
Interpretive Data
Refer to report
This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.
Laboratory Developed Test (LDT)
Note
Hotline History
CPT Codes
88342; 88341 x3
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0049199 | Client Case or Ref # | 94736-6 |
0049303 | Mismatch Repair by IHC, Result | 50595-8 |
0049305 | Mismatch Repair by IHC with MLH1 | 50322-7 |
0049310 | Mismatch Repair by IHC with MSH2 | 50323-5 |
0049320 | Mismatch Repair by IHC with MSH6 | 50324-3 |
0049325 | Mismatch Repair by IHC with PMS2 | 50328-4 |
3002969 | MSI Tissue Source | 31208-2 |
Aliases
- MLH1 IHC
- MMR IHC
- MMR Immunostaining
- MSH2 IHC
- MSH6 IHC
- MSI
- MSI Antibody Immunostaining
- MSI IHC
- PMS2 IHC