Test Name: KI-67
The Ki-67 antigen is a nuclear protein expressed during all active phases of the cell cycle (G1, S, G2 and M-phase), but absent in resting cells (G0-phase). It is used to evaluate the fraction of proliferating cells (proliferation index) present in a cellular infiltrate. This evaluation is important for diagnostic purposes (e.g. to identify aggressive B-cell lymphomas and differentiate from low-grade B-cell lymphomas) and prognostic purposes (increased proliferation index may be associated with poor prognosis in some neoplasms). The Ki-67 antigen is poorly preserved in acid decalcified tissues and therefore it may be of suboptimal quality in bone marrow biopsy samples, bone biopsy and bone resection samples.
A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen type or one (1) unbaked, unstained slide cut at 4-5 microns for H&E staining (required) and two to three (2-3) positively charged unstained slides cut at 3-4 microns for each test/antibody ordered.
Storage and Transport
Use cold pack during transport of paraffin blocks and unstained slides. Cold pack should not be placed in direct contact with the specimen during shipping
Specimen Rejection Criteria
Turn Around Time (TAT): 2-3 Days
CPT Codes*: 88341, 88342, 88360
*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.