Mismatch Repair Protein Immunohistochemistry
Label Mnemonic: IMMR
Epic Lab Code: LAB7430
Downtime Form: A-1a Miscellaneous Request
Immunopathology
5238 RCP
356-2688
Specimen(s):
Formalin Fixed, Paraffin Embedded Tissue containing Tumor (please specify case and block number on requisition)
Turn Around Time:
Within 5 days upon receipt
Reference Range:
An interpretive report will be provided.
Comments:
Mismatch repair protein immunohistochemistry is useful to screen for Lynch syndrome and to determine the functional status of the DNA mismatch repair apparatus.

A normal result argues against the presence of Lynch syndrome and indicates with a high degree of specificity that the tumor has proficient mismatch repair function.

Microsatellite instability testing is complementary and may be used to confirm a normal result. Depending on the pattern of staining with an abnormal result, additional testing and/or genetic counseling may be indicated.

Test results should be interpreted in the context of clinical findings, family history, and other laboratory data. Errors may occur in our interpretation of results if information given to us is inaccurate or incomplete.
Methodology:
Immunohistochemical staining is used to determine the presence or absence of protein expression for MLH1, MSH2, MSH6, and PMS2.
CPT Code:
"MLH-1, Immunostain" - 88341, 88342 (if appropriate)
"MSH-2, Immunostain" - 88341, 88342 (if appropriate)
"MSH-6, Immunostain" - 88341, 88342 (if appropriate)
"PMS-2, Immunostain" - 88341, 88342 (if appropriate)