Primary peritoneal cancer after bilateral salpingo-oophorectomy in two patients with Lynch syndrome.

Abstract

Women with Lynch syndrome or hereditary nonpolyposis colorectal carcinoma (HNPCC) have a 40-60% lifetime risk of endometrial cancer and a 7-12% lifetime risk of ovarian cancer. Risk-reducing surgery, including hysterectomy and bilateral salpingo-oophorectomy (BSO), is currently recommended once child bearing is complete. We describe two cases of primary peritoneal cancer after BSO in women with Lynch syndrome or HNPCC. The first patient was a 44-year-old woman who underwent hysterectomy with BSO for benign disease. She presented 12 years later with a pelvic mass and was diagnosed with a high-grade serous primary peritoneal cancer. Genetic testing showed a mutation in the MSH2 DNA mismatch repair gene. The second case was a 58-year-old woman who had a hysterectomy and BSO for endometrial cancer. She developed a high-grade serous primary peritoneal cancer 8 years later and was found to have a mutation in the PMS2 DNA mismatch repair gene. Women with Lynch syndrome or HNPCC should be counseled that they may be at risk for developing primary peritoneal cancer despite undergoing gynecologic cancer risk-reducing surgery. The magnitude of this risk remains to be determined.