Microsatellite instability analysis for the screening of synchronous endometrial and ovarian cancer in Lynch syndrome.

We report on a case of synchronous endometrial and ovarian cancer in a patient with Lynch syndrome. An endometrial biopsy performed during routine screening revealed microsatellite instability (MSI) and loss of expression of human mutL homolog-1 (MLH1) and postmeiotic segregation increased-2 (PMS2) in a setting of complex hyperplasia. Whereas gynaecological screening including clinical examination, pelvic ultrasound, and endometrial biopsy, has not proven its benefit, our case report points out the place of MSI analysis and immunohistochemical investigation of mismatch repair protein expression in endometrial samples during gynaecological screening.