Microsatellite Instability PCR with Interpretation
| Label Mnemonic: | MSI |
| Epic code: | LAB1980 |
| Order form: | Molecular Oncology Requisition |
| Supply order: | Supply Order Form |
| Billing: | Billing Policies |
| CPT code: | 81301 |
Specimen(s):
Formalin fixed, paraffin embedded tissue block or 10 unstained 5-10 μM slides at 20-25°C and an H&E slide of the tissue
Minimum:
Tumor cells more than 50% of the total tissue and greater than
10mm2 in surface area on the block.
Must also submit a healthy tissue specimen or peripheral blood from the same subject for comparison of microsatellite markers.
Must also submit a healthy tissue specimen or peripheral blood from the same subject for comparison of microsatellite markers.
Rejection Criteria:
Specimens fixed in B5 fixative or that have been decalcified will not
be accepted. Tumor specimens containing less than 50% tumor cells or
are less than 10mm2 in area may be unacceptable.
Testing
Schedule:
Weekly
Turn Around
Time:
7-10 working days
Reference Range:
Microsatellite Stable
Methodology:
Multiplex PCR followed by Fluorescence Capillary Electrophoresis
Instructions:
Submit formalin fixed, paraffin embedded tissue block or 10
unstained
5-10 μM slides and an H&E slide along with the requisition. Please include surgical pathology report and relevant clinical information.
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.
5-10 μM slides and an H&E slide along with the requisition. Please include surgical pathology report and relevant clinical information.
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.
Sample
Processing:
Formalin-fixed, paraffin embedded tissue should be submitted.
Submit a whole blood EDTA specimen from the same patient or 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.
Submit a whole blood EDTA specimen from the same patient or 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.
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 room temperature.
Protect block or slides from excessive heat and ship in cooled container during summer months.
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 room temperature.
Protect block or slides from excessive heat and ship in cooled container during summer months.
CPT Code:
81301