Immunohistochemistry (IHC)
Test Description
MGMT (O-6-methylguanine-DNA methyltransferase) is a DNA repair enzyme. MGMT protects cells from alkylating toxins, and is an important factor in drug resistance to alkylating therapeutic agents. It is expressed in normal human tissues and is overexpressed in many types of tumors, but epigenetically silenced in other tumors. MGMT silencing is a marker associated with poor prognosis, but is a good predictive marker for response to alkylating agent chemotherapy. MGMT overexpression is associated with BCNU (carmustine) resistance in malignant gliomas.
Specimen Requirements
  • A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen type
  • or
  • One (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4-5 microns) for each test/antibody ordered
  • Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Storage and Transportation
Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.
CPT Code(s)*
88342 x 1 or 88341 x 1; 88360 x 1
Turnaround Time
Global: 48 hours, Tech-Only (stain only): 24 hours
Level of Service
Stain Only

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.