RESUMO
The tumoral lesions proceeding of ovary in the newborns are the 3-6% of all abdominal tumors. The most frequent tumor is ovarian follicular cyst which will be diagnosed prenatally. As a result of ovarian stimulation by fetal gonadotrophins, maternal estrogen and placenta + gonadotrophins. Maternal antecedents reported diabetes, toxemia and isoimmunization. The most frequent complication is torsion. We present the case of one female newborn, with abdominal mass present by abdominal palpation referred of the first gestation of mother with 27 years of age, with primary sterility of 11 years without treatment, with toxemia during the pregnancy. The abdominal x-film show a intraperitoneal mass the ultrasound show cystic and solid mass, without determined origin, and the scan magnetic resonance (MR) a tumoral mass with origin in the pelvic hole with extension to the infrahepatic zone. The surgical finding was left ovarian cyst with left oophorectomy and salpingectomy.