10–14 October 2010, Prague, Czech Republic Poster abstracts P18.11 Unilateral pulmonary agenesis: prenatal imaging and outcome in three cases A. Kennedy 1,2 , J. L. Byrne 2 , T. C. Winter 1 , P. J. Woodward 1,2 1 Radiology, University of Utah Hospital and Clinics, Salt Lake, UT, USA; 2 Obstetrics and Gynecology Department, University of Utah Hospital and Clinics, Salt Lake, UT, USA Objectives: To review the imaging findings and outcome of unilateral pulmonary agenesis in the fetus. Methods: Retrospective review at a single academic center. Results: Case 1: Presented at 29 weeks with severe IUGR, occipital encephalocele, left renal agenesis, arthrogryposis, small stomach and left lung agenesis. The infant died at 30 hrs of age, no intervention occured. Case 2: Presented at 18 weeks with unilateral left lung agenesis, small right lung, right renal agenesis, interrupted aortic arch, facial dysmorphism. The infant lived about 30 mins after resuscitation attempts ceased. Case 3: Presented at 20 weeks with left pulmonary agenesis, right renal agenesis, club foot, caudal regression sequence and other vertebral segmentation anomalies as well as a single umbilical artery. The infant survived; she had emergency repair of aortic coarctation and is alive at age 3. All had normal karyotype. Conclusions: Pulmonary agenesis is described as an isolated finding in the pediatric literature however 50% of live born infants have features of the VACTERL association. Our series suggests that the prognosis is guarded when the diagnosis is made prenatally. All three had significant associated abnormalities, some of which were not appreciated on fetal US or MRI. Two infants died in the neonatal period and the third had a difficult time during repair of an unanticipated coarctation of the aorta. Supporting information can be found in the online version of this abstract. Autopsy in case #1 shows the empty left pleural cavity posterior to the retracted heart, above the intact diaphragm and liver. P18.12 Congenital high airway obstruction syndrome and duodenal atresia: an unusual combination J. Coletta , K. Fuchs, J. Vink, A. van der Veer, L. Simpson Center for Prenatal Pediatrics, Columbia University Medical Center, New York, NY, USA Background: Congenital high airway obstruction syndrome (CHAOS) refers to a rare prenatal diagnosis of upper airway obstruc- tion resulting in the sonographic finding of large echogenic lungs, flattened or inverted diaphragms, and dilated airways distal to the obstruction. Duodenal atresia, the leading cause of intestinal obstruction among newborns, is characteristically described as the ‘double bubble’ sign resulting from a dilated fluid-filled stomach and proximal duodenum. Although both of these anomalies have been previously reported, they are usually isolated. Case: We report a case and associated images of a 27 year old multiparous patient who presented for fetal anatomic survey in the mid-second trimester. Initial ultrasound revealed a fetus with a markedly enlarged thoracic circumference, echogenic lungs bilaterally, and an inverted diaphragm. In addition to prominent airway markings, a dilated tubular structure was seen extending down the midline from the fetal neck to the stomach suggestive of a dilated esophagus. The fetal stomach and proximal duodenum also appeared dilated consistent with a ‘double bubble’ sign. The constellation of findings was felt to be consistent with a diagnosis of CHAOS and concurrent duodenal atresia. The patient was counseled regarding the diagnoses, and opted for termination of pregnancy. Postmortem evaluation confirmed the suspected diagnoses and revealed laryngeal stenosis, tracheoesophageal fistula, pulmonary hyperplasia, and duodenal atresia. Fetal karyotype was noted to be 46,XY. Conclusion: Although many cases have been reported with either duodenal atresia or CHAOS, we present the first reported case of prenatally-diagnosed CHAOS and duodenal atresia in the same fetus. P18.13 Spontaneous resolution of fetal pleural effusion E. Dunn , K. McNamara Wexford General Hospital, Wexford, Ireland We present and discuss the case of spontaneous resolution of unilateral pleural effusion in a fetus with diagnosed trisomy 21 and duodenal atresia. Background: A 36 year old P0 + 1, presented for a routine anatomy scan at 20 weeks. Scan findings included polyhydramnios with an AFI of 32.4 cm and a ‘double bubble’. Subsequent amniocentesis revealed a male fetus with trisomy 21 and a detailed scan confirmed duodenal atresia. Initially follow up scans were normal however, at 30 weeks a right sided pleural effusion and scalp oedema was noted. Thoraco-amniotic shunt was discussed however on weekly follow up scans the pleural effusion began to resolve spontaneously. At 31 weeks a detailed fetal echocardiogram confirmed a suspected complete AV septal defect. By 33/40 there was complete resolution of the effusion. At 37 weeks the patient presented and delivered a male infant weighing 2.48 kilos with apgars 9 and 10. The infant was transferred at 36 hours of age to a specialist paediatric unit and has successfully undergone surgery for his duodenal atresia and is awaiting cardiac surgery. Discussion: Fetal pleural effusions are uncommonly reported in the literature. They are found either in isolation or as part of hydrops fetalis. They occur in approximately 1 in 10,000 deliveries and are associated with a 10% risk of aneuploidy, mainly trisomy 21, and Turners syndrome. Following postnatal diagnosis most are found to be chylous in origin, however other associations include congenital pulmonary lymphangiectasia or they can be secondary to structural abnormalities such as congenital diaphragmatic hernias or lung/mediastinal tumours. Isolated pleural effusions are a diagnosis of exclusion. Management is either conservative or by antenatal thoracocentesis. They can also be treated in the immediate postnatal period. Isolated pleural effusions appear to have a much better prognosis than those that present with either hydrops or polyhydramnios. Our infant did have associated polyhydramnios but so far has done well. P18.14 Prenatal utrasonographic findings of a fetal dorsal giant congenital nevus M. Miranda, G. Nazzaro , M. Locci, M. Pisaturo, A. D’Ambra, G. De Placido Ob/Gyn, Univ. Federico II Naples, Naples, Italy Giant congenital nevi occur in 1 in 20000 live births, and may be associated with by proliferative nodules. They are usually disfiguring and associated with complications of malignant melanoma, and neurocutaneous melanosis. Here we present a case of prenatal diagnosis of this pathology. A 39-year-old woman, gravida 2 para 1 was referred to our center for sonographic examination since the presence of an unknown mass on the fetal shoulder. The scan revealed a fetus of 29+6 weeks of gestation with normal amniotic fluid. An irregular cystic-solid mass of heterogeneous echogenicity (12 × 10 × 9 cm in size) was detected on the surface of the left shoulder covering the dorsal chest wall. The mass was mostly subcutaneous and did not appear to penetrate the skeleton. Color Doppler investigation showed an intense and chaotic low resistance vascularization (RI 0.48) in the mass. There was no other fetal Ultrasound in Obstetrics & Gynecology 2010; 36 (Suppl. 1): 168–305 241