Early-onset primary peritoneal carcinoma from atypical cells after risk-reducing salpingo-oophorectomy for mutation carrier: a case report.

Risk-reducing salpingo-oophorectomy (RRSO) in mutation carriers is performed to reduce carcinogenesis. It decreases the ovarian, tubal, and peritoneal cancer risk to 3.5-4.3% and breast cancer risk to 30-40%. According to a previous study, despite RRSO, 3.4% of patients develop breast cancer and 0.8% develop peritoneal cancer. However, the long-term risk of recurrence and appropriate treatment for patients with unsuspected neoplasia after RRSO are unclear. Case: A 61-year-old woman who had a mutation underwent RRSO. Her pelvic washing cytology showed atypical cells, and similar atypical cells were identified on her fimbria. She underwent strict surveillance. Elevated CA125 levels and increased ascites in the pelvic cavity were detected by routine surveillance at 18 months after RRSO. She underwent staging laparotomy and was diagnosed with primary peritoneal carcinoma stage IIIC. It is helpful to perform surveillance by transvaginal ultrasound and serum CA125 analyses in cases that require strict management. The appropriate intervention should be considered for cases in which atypical cells or non-invasive carcinoma are detected after RRSO.