Alphabetical Test listing

PMS2 by IHC-12376 - Technical only, 12379 - Technical & interpretation

12376 - Technical only, 12379 - Technical & interpretation
Microsatellite instability marker
  • All IHC stains will include a positive control tissue
  • Used in a panel to identify patients at high risk for having hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome
  • IHC analysis is helpful for identifying the gene(s) responsible for the defective DNA mismatch repair within the tumor; the majority of MSI-H tumors show a loss of expression of at least 1 of the 4 mismatch repair genes
  • MSI-H phenotype or loss of protein expression by IHC within a tumor does not distinguish between somatic and germline mutations. Genetic testing of the gene indicated by IHC analysis can help to distinguish between these 2 possibilities

Submit a formalin-fixed, paraffin embedded tissue block


Formalin-fixed, paraffin embedded (FFPE) tissue block


FFPE tissue section mounted on a charged, unstained slide


Ambient (preferred)

  • Unlabeled/mislabeled block
  • Insufficient tissue
  • Slides broken beyond repair
AHL - Immunohistochemistry
Mo - Fr
1 - 2 days

Immunohistochemical staining and microscopic examination


If requested, an interpretive report will be provided



  • Hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome, is an autosomal dominant hereditary cancer syndrome associated with germline mutations in the mismatch repair genes: MLH1, MSH2, MSH6, and PMS2
  • Patients with HNPCC have an increased risk of developing colorectal and endometrial cancer
  • Mutations of the PMS2 gene confer the lowest risk for any of the tumors within the HNPCC spectrum

Staining pattern

  • Nuclear staining of internal control lymphocytes, and PMS2 intact tumor cells
  • Absence of staining for PMS2 in tumor nuclei indicates loss of protein expression for this marker


  1. Burgart LJ: Testing for defective DNA mismatch repair in colorectal carcinoma. A practical guide. Arch Pathol Lab Med 2005;129:1385-1389.
88342 - 1st stain
88341 - each additional stain