Methodology
Immunohistochemistry (IHC)
Test Description
Phosphohistone H3 (PHH3) is a marker of cells in the late G2-M phase of the cell cycle. It is not expressed in apoptotic cells which may be confused with mitotic figures on a routine H&E stained slide. PHH3 can be used as a surrogate of mitotic activity or as an independent prognostic marker in breast carcinomas.
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)*
88361 x 1; 88360 x 1
Turnaround Time
Global: 48 hours, Tech-Only (stain only): 24 hours
Level of Service
Global
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.