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

Methodology:

Multiplex PCR followed by Fluorescence Capillary Electrophoresis

Sample
Processing:

Formalin-fixed, paraffin embedded tissue should be submitted.
Submit a whole blood EDTA specimen from the same patient or another 
tissue from an unaffected area (formalin-fixed, paraffin embedded 
tissue) of the same patient.
Label transport tube with two patient identifiers, date and time of 
collection.
Lavender tube is sent as whole blood, no processing necessary.
Relevant clinical information must be submitted with specimen in order 
to provide correct interpretation of test results.
Specimen source is required on requisition for processing.

Sample
Storage:

Tissue Specimen - Freeze immediately and store frozen or send 
Formalin-fixed paraffin embedded blocks.
Refrigerate whole blood specimens 2-8 degrees C.

Transport
Instructions:

Place requisition into outside pocket of bag.
Place specimen into zip-lock type bag, seal bag.
Place coolant packs into styrofoam container.
Coolant packs up to 8 hours.
Frozen Tissue - Ship frozen on dry ice.  Ship express mail with 
overnight delivery.  Formalin-fixed paraffin embedded blocks ship at 
ambient temperature.

Instructions:

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.

CPT Code:

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