MSI
Unique Identifier:
ML-S017
Name on Requisition:
MSI
Product Line:
ST
Panel Group:
Solid Tumor Panels
Panel Name:
MSI
Methodology
Molecular
NGS
Test Description and clinical significance
Genes
MSI
Disease:
multiple solid tumors including colorectal, endometrial, and gastric cancers
Microsatellite instability (MSI) is a molecular hallmark of defective DNA mismatch repair (MMR), observed in multiple solid tumors including colorectal, endometrial, and gastric cancers. Detection of MSI status provides key diagnostic, prognostic, and therapeutic information, particularly for identifying Lynch syndrome and eligibility for immunotherapy. This assay evaluates MSI by analyzing length variations in microsatellite loci from tumor DNA.
Specimen Requirements
Preparation:
FFPE tissue or slides
Collection:
In case of FFPE sections, 5-10 sections are recommended at 4 to 10 micron.
Stability:
Stored at room temperature
Unacceptable Conditions:
Specimen submitted is in the incorrect fixative. Insufficient specimen (less than 10% of tumor). Bacterial over growth. Submitted with incomplete requisition form (unless a requisition is subsequently sent). Unlabeled or improperly labeled specimens, without contact information or when failing to
reach the ordering physician for clarification. Decalcified specimens. Improperly stored DNA.
Storage & Transport
Store FFPE blocks and slides at room temperature. Slides may be stored at ambient
CPT(s)
81301
TAT
7
Requisition Type
ST
Levels of Service
Full
DexS Code
Z052K
Prefix
MI
*The CPT codes provided are for informational purposes only and are based on AMA guidelines The billing party is solely responsible for correct CPT coding.
