Table 4.

Microsatellite instability low (MSI-L) endometrial adenocarcinomas with associated immunohistochemistry (IHC), family history and germline test results

Study Number	MSI Result	IHC Result	Age at Diagnosis	FDR with LATs1	Germline Testing Result	Clinical Interpretation
1009	MSI-L	Intact Staining	59	Daughter: precancerous colon polyp at age 48	No MSH6 mutation detected	Presumed sporadic
1021	MSI-L	Intact Staining	59	No	No MSH6 mutation detected	Presumed sporadic
1066	MSI-L	Loss of MLH1/PMS2 MLH1 methylation present	62	No	Not performed	Presumed sporadic
1108	MSI-L	Intact MLH1, MSH2, MSH6 staining2	53	No	MSH6 VUS3	Uncertain
1115	MSI-L	Intact Staining	52	No	Insurance denied testing	Uncertain, likely sporadic
1129	MSI-L	Intact Staining	54	No	Not offered genetic testing4	Presumed sporadic

¹FDR, First Degree Relative; LAT, Lynch Syndrome Associated Tumors (colorectal, stomach, endometrial ovarian, biliary, sebaceous adenomas)

²IHC for PMS2 unsuccessful; both tumor and internal positive control lacked staining

³VUS, variant of unknown significance

⁴Endometrial cancer was believed to be secondary to the concurrent ovarian granulosa cell tumor