22nd World Congress on Ultrasound in Obstetrics and Gynecology Poster abstracts in several of the ‘‘cysts’’. MRI at 23 wks confirmed normal fetus and placenta with thick, high-signal myometrium and abnormal blood pooling on GRE sequences. The diagnoses of molar twin and triploidy were dismissed. In a case reported by Uotila et al. (massive multicystic dilatation of the uterine wall with myometrial venous thrombosis) maternal anemia, marked uterine enlargement, and abdominal discomfort occurred necessitating Cesarean delivery at 30 wks complicated by > 3L blood loss. Our patient was counseled re the risk of similar complications. She was managed conservatively and, although the uterus was abnormally large, she was not anemic or otherwise symptomatic. Spontaneous labor at 39 weeks resulted in vaginal delivery with manual extraction of the placenta for delayed third stage. There was no postpartum hemorrhage. Placental pathology was normal. Although the US and MR appearances are almost identical to Uotila’s case, our patient had a benign course and a NSVD. It is important to differentiate this appearance from GTN as an excellent pregnancy outcome is possible. Careful clinical and ultrasound surveillance is a reasonable management strategy. Supporting information can be found in the online version of this abstract. P33.03 Nonimmune hydrops fetalis secondary to large bilateral simple renal cyst D. Acar, H. Aslan Istanbul Kanununi Sultan Suleyman Teaching and Training Hospital, Istanbul, Turkey Cystic abdominal masses in the fetus are not uncommonly encountered in routine antenatal ultrasound examination and physicians face impressive challenges in diagnosing and managing them. The majority of fetal abdominal cysts originate from the urogenital tract. Case: A 30-year-old pregnant woman at 31 weeks of gestation presented with fetal intraabdominal cystic mass found during routine prenatal ultrasonography. The cystic mass arising from left was measuring 74 × 40 mm and the right was measuring 93 × 60 mm on transverse diameter. During sonographic examination two weeks later we noticed the development of fetal hydrops. After one course of antenatal steroid prophylaxis left sided cystic mass was successfully drained. Cesarean delivery was performed due to nonreassuring fetal heart rate pattern. The male neonate was operated and the histopathological examination revailed renal parenchymal tissue. Discussion: Abdominal cystic lesions in particular are a challenging problem with a long list of differential diagnoses and frequent false positives. Multicystic dysplastic kidney was unlikely given the normalcy of the amniotic fluid volume. Normalization of the renal function after long term peritoneal dialysis demonstrated by the 99Tcm-MAG3 renal scintigraphy performed during neonatal period also exclude multicystic dysplastic kidney and urinary obstruction. In conclusion because the origin of the fetal cysts sometimes cannot be identified certainly despite the utilization of advanced imaging technologies invasive procedures may be useless and indeed be hazardous. Supporting information can be found in the online version of this abstract. P33.04 Importance of antenatal MRI in the diagnosis of curarrino syndrome in a familial case C. Desveaux 1 , N. E. Russell 1 , C. Cretolle 1 , P. Sonigo 1 , A. Millischer 1 , G. E. Chalouhi 1 , S. Sarnacki 1 , L. J. Salomon 1,2 , J. Bernard 1 , Y. Ville 1,2 1 Maternit´ e, Hopital Necker Enfants Malades, AP-HP, Universit´ e Paris Descartes, Paris, France; 2 Soci´ et´ e Fran¸ caise pour l’Am´ elioration des Pratiques Echographiques, SFAPE, Paris, France The Currarino syndrome is an autosomal dominant inherited syndrome which includes a malformed sacrum, a presacral mass and malformations of the anus or rectum. We present and illustrate a case of antenatal diagnosis of Curarrino syndrome in a family. A 28 years old woman primipara was following in our maternity for a personal history of an incomplete form of Curarrino syndrome. She had an anorectal malformation which required surgery during childhood and had a uterus didelphys. Her brother, father and paternal grand mother were also affected and the classical HLXB9 mutation in Curarrino syndrome was found. The second trimester antenatal ultrasound revealed a caudally inserted spinal cord and a suspicion of an anorectal malformation. An MRI at 29 weeks confirmed the ultrasound findings of an abnormal spinal cord and on sagittal T1 weighted sequences an anorectal stenosis. Additionally in T2 weighted sequences, it revealed a sacral anomaly, a presacral mass, meningeal ectasis and a uterus didelphys. Postnatal examination confirmed an anorectal stenosis, which was easily dilated, and a uterus didelphys. The sacral anomaly was found to be a scimitar- shaped sacrum but the presacral mass was not found. The spinal cord stopped at the level of S1 with a filum lipoma which was not seen on antenatal MRI. The prenatal diagnosis of lipoma is difficult due to the fat signal which is not in highsignal before birth. The sagittal T1 weighted sequences are essential to make the diagnosis of an anorectal malformation as optimal ultrasound imaging of this region is difficult to obtain. We show here the importance of antenatal MRI in enhancing and completing diagnosis to enable informed patient counseling and to provide for appropriate neonatal care. P33.05 Imaging a complete hydatiforme mole, previa lying and co-existing normal fetus L. Seinen 1 , I. Krabbendam 1 , K. Kamphuis 2 , M. Woiski 1 , F. P. Vandenbussche 1 1 Obstetrics and Gynaecology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 2 Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands We present a case of a complete hydatide mole, previa lying with a co- existing normal fetus. We will discuss the role of imaging techniques in diagnosing and estimating the risks of this pregnancy. There is a high risk of pre-eclampsia, premature delivery, perinatal death and hemorrhagia postpartum and a chance of persistent throphoblast disease. A woman was referred with vaginal bloodloss. At 19 weeks gestation, a molar mass presenting as previa, with a co-existing fetus was diagnosed on ultrasound. After counseling, the couple desired to continue the pregnancy. Weekly ultrasound revealed a stable appearance of the mole. A MRI was performed at 26 weeks, to assess the exact location and to rule out a placenta accrete. The patient had an uneventful pregnancy until 33 weeks. A Cesarean section was performed because of increasing bloodloss. First, sheets were placed in the uterine arteries, to inflate in case of extensive hemorrhage. The uterus was incised vertically. A healthy son was born. The mole could easily be removed. Total bloodloss was 800 ml. Pathologic and cytogenetic research showed a complete, diploid hydatiform XY mole, both alleles paternally derived and a normal, diploid, placenta. The hCG levels normalized 3 weeks 306 Ultrasound in Obstetrics & Gynecology 2012; 40 (Suppl. 1): 171–310