The revised Bethesda guidelines for testing colorectal tumors for microsatellite instability (MSI)
Colorectal cancer diagnosed in a patient who is less than 50 years of age
Presence of synchronous, metachronous colorectal, or other HNPCC-associated tumors, regardless of age
Colorectal cancer with the MSI-H like histology diagnosed in a patient who is less than 60 years of age
Colorectal cancer diagnosed in a patient with 1 or more first-degree relatives with an HNPCC-related tumor, with 1 of the cancers being diagnosed under age 50 years.
Colorectal cancer diagnosed in a patient with 2 or more first- or second-degree relatives with HNPCC-related tumors, regardless of age.