Simple right ovarian cyst in a 5-week-old baby girl.Postnatal transabdominal grayscale sonography reveals a thin-walled, unilocular, anechoic cyst in the right side of the peritoneal cavity (arrow) consistent with a simple right ovarian cyst. Two small, round, thin-walled anechoic lesions are seen along the inferior margin of the cyst (arrowheads), representing "daughter cysts."