RADIOLOGY: FEMALE REPRODUCTIVE: Case# 33008: LARGE OVARIAN CYST, GRAVID UTERUS. 27 year old woman in 20th week of pregnancy with roughly 10 x 10 cm cystic mass in the cul-de-sac. The study has been ordered for preoperative evaluation prior to cystectomy. A 9 x 10 x 11 cm cystic mass is visualized in the cul-de-sac with extension into the presacral space. The mass displaces the uterus cephalad. The cystic mass is of predominantly fluid intensity (hypointense on T1 weighted and hyperintense on T2 weighted images) with a few septations noted in the inferior aspect of the cystic mass. Cystic mass homogeneous without evidence of soft tissue components within the mass. The cyst wall is of uniform thickness without evidence of papillary excrescences. The cystic mass is clearly distinct from the uterine wall which it abuts. A left ovary measuring approximately 2 cm is visualized on the T2 weighted axial images of the pelvis on image #30 of 48. A right ovary distinct from this large cystic mass is not visualized. A gravid uterus is noted with anterior placenta. Although the examination was not tailored for evaluation of the fetus, the fetus appears grossly unremarkable. There is no evidence of abdominal or pelvic lymphadenopathy. The remainder of the abdominal and pelvic viscera appear grossly unremarkable. There is no evidence of hydronephrosis. No free fluid is visualized in the abdomen or pelvis.