Neonatal Ovarian Cyst Etiology: maternal stimulation by estrogen Imaging: large ovarian cyst, prominent endometrial stripe in the uterus Treatment: if > 4 cm intervention required to prevent ovarian torsion Radiology Cases of Neonatal Ovarian Cyst T1 coronal (left) and T1 sagittal (right) and T2 axial (below) MRI images show a heterogeneous intraperitoneal mass that appears to have hemorrhagic and calcified components. In the operating room this mass was found to be torsed. Surgery Cases of Neonatal Ovarian Cyst Surgical image shows a large circular and soft mass that was adherent to, but not invading, the hepatic flexure, omentum, and distal ileum and which was no longer connected to any pelvic structures. There was no ovarian tissue in the right adnexa. The left ovary was normal. Gross Pathology Cases of Neonatal Ovarian Cyst Gross pathological image (above) shows the mass to be circular and cystic. Upon sectioning, the thin-walled cyst was filled with hemorrhagic, fibrinous material (below). Solid areas were not present. Gross pathological image shows the mass to be circular and cystic (above). Upon sectioning, the thin-walled cyst was filled with hemorrhagic and fibrinous material (below).