Case report

A 25-year-old woman, with a non-contributive history, presented to our unit at 31st week of pregnancy. Her previous sonography performed at 22 weeks was reported to be normal. Our ultrasound revealed an abdominal hypoechoic ovoid mass located in the inferior abdomen and pelvis of the fetus. The fetal bowels were not dilated and the kidneys looked normal. No signs of aneuploidy were found. The parents refused amniocentesis and the neonate was delivered at 37 weeks. Postnatal sonography found ascites in the neonate originating from the ruptured cyst described above. The next day, the amount of intraperitoneal fluid regressed.

One month later the clinical examination of the baby was normal and our supposed diagnosis was a ruptured hamartoma. Six weeks later the cyst appeared again and the baby presented with signs of an acute abdomen requiring a surgical intervention. The final diagnosis was the ruptured biliary cyst.

Images 1, 2: Transverse scans of the fetal abdomen showing the cystic structure within its anterior part.

Images 3, 4: Color Doppler transverse scans of the fetal abdomen showing the cystic structure within its anterior part. The image 4 shows in its left part the fetal urinary bladder being passed by the umbilical arteries, and in its right part, a transverse scan obtained more cranially with the cyst in the anterior part of the abdomen.

Images 5, 6: Transverse scans of the fetal abdomen showing the cystic structure within its anterior part.

Image 7: Parasagittal scans show normal appearance of both fetal kidneys.