A 43-year-old woman presented with abnormal vaginal bleeding. Endometrial carcinoma was found on dilation and curettage. Hysterectomy and surgical staging confirmed stage IA endometrial cancer. Family history was significant for prostate cancer in her father and paternal grandfather.
Her tumor was screened for Lynch syndrome by immunohistochemistry staining for DNA mismatch repair proteins (mutL homolog 1 [MLH1]; MutS homologs 1 and 6 [MSH1, MSH6]; PMS 1 homolog 2 [PMS2]) and microsatellite instability testing (MSI)1 (Table 1).
Usha L, Dewdney SB, Buckingham LE. Tumor Screening and DNA Testing in the Diagnosis of Lynch Syndrome. JAMA. 2016;316(1):93-94. doi:10.1001/jama.2016.8286