Microsatellite Instability Analysis (MSI) in Tumors
Indication
For carcinomas, particularly of colonic or gynceologic origin, to identify those tumors with MSI+ phenotype, that can then be further evaluated for alterations in mismatch repair genes. MSI+ tumors can be seen sporadically or in hereditary non-polyposis colon cancer (HNPCC) syndromes.
Methodology
A panel of five markers (BAT25, BAT26, D2S123, D5S346, D17S250) recommended by the National Cancer Institute (NCI) and BAT40 are tested. Fluorescently labeled primers are used in a multiplex PCR assay. Tumor and normal tissues from each patient are analyzed in parallel.
Test Parameters
The careful selection of an involved tumor sample and normal (uninvolved) sample is essential for appropriate interpretation of results.
Turnaround Time
Seven to 10 days
Sample Requirements
Sections of microdissected, paraffin-embedded tissue fixed on five to six slides, with areas of normal tissue and tumor clearly indicated. Please contact our laboratory for more information on submission requirements for this test.
Please provide a copy of the corresponding pathology report.
CPT Codes
83890 (DNA Isolation), 83900, 83909, 83912
Additional charges may apply for tissue extraction.
The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.