TMSI – “Microsatellite Instability, Tumor”

Update to specimen requirements, alternate specimen, stability, and performed days

Patient Preparation: Pathology report must accompany specimen in order for testing to be performed. This assay requires at least 40% tumor nuclei for endometrial specimens and at least 20% tumor nuclei for colorectal specimens.

Collect: Tissue block

Specimen Preparation: Send a formalin-fixed paraffin embedded tissue block, (non-decalcified), with approximately 72 mm(2) area of tumor.

Minimum Volume: 18 mm(2) area of tumor

Alternate Specimen:

Tissue slide: 1 Slide stained with hematoxylin and eosin and 10 Unstained, nonbaked slides with 5-micron thick sections of the tumor tissue.
Note: The total amount of required tumor nuclei can be obtained by scraping up to 10 slides from the same block. Unused unstained slides will not be returned.

Stability:

Room temperature: Indefinitely
Refrigerated: Unacceptable
Frozen: Unacceptable

Performed Days: Varies