Specimen

Various

Collection Medium:

Minimum:

Tissue block should contain 50% tumor

Rejection Criteria:

Specimens fixed in B5 fixative; specimens containing less than 50% 
tumor may be unacceptable

Testing Schedule:

Weekly

Analytic Time:

7 working days

Reference Range:

By report

Comments:

Tumor tissue and normal tissue should be obtained as part of the 
surgical procedure for testing.  The tissue should be formalin-fixed, 
paraffin embedded and reviewed by a surgical pathologist prior to MSI 
testing.  A block containing normal tissue (non-tumor) should be 
submitted for testing in addition to a block containing at least 50% 
tumor.  Acceptable tissue for the non-tumor block is tissue with a high 
nuclear content, preferably benign lymph node tissue if available.  
Blood submitted in EDTA or sodium citrate is acceptable for the normal 
block if tissue is not available. An H&E stained glass slide from both 
blocks should also be submitted.

Methodology:

Multiplex PCR followed by Fluorescence Capillary Electrophoresis

CPT Code:

83907(X2), 83909(X2), 83900, 83901, 83912-26