[Peritoneal serous borderline tumor discovered during a cesarean section. A case report].

During a caesarean section performed in a 36-year-old woman, we discovered small granulations on the pelvic peritoneum. Biopsies were performed. The diagnosis of primitive borderline serous tumor was confirmed by pathologists. The patient was operated twice: once for diagnostic evaluation, and again six months later. A radical gesture was then decided for therapeutic purposes. The optimal attitude regarding these borderline peritoneal tumors in young women remains difficult and requires a multidisciplinary workout between pathologists and surgeons.