Dept of Obstetrics and Gynecology, Hôpital Félix Guyon ** Cabinet d"Echographie, Route de Moufia Saint-Denis, Reunion Island, France. Ph : 0262 90 55 22.
This is a 34-year-old-primigravida with the first and the second scan normal. At 33 weeks, a right pyelectasis was diagnosed. The patient was referred to our unit at 34 weeks. The fetus had a normal growth. In fact, the kidney anomaly seemed to be a polycystic dysplasia without pyelocaliceal dilatation. The bladder and the amniotic fluid were normal. The left kidney was also normal. There was an intrauterine growth restriction. The patient refused to perform an amniocentesis. The baby was born at 37 weeks (1840 g).
At day five, a scan was performed and we could see a normal left kidney and a multicystic right kidney without pyelocaliceal dilatation. The baby left the neonatal unit at day 8. The baby received penicillin for two months.
At eight months, a renal scan was repeated. The left kidney was normal (60 mm) with a normal corticomedullary differentiation. Nevertheless, the right kidney could not be seen and seemed to have disappeared.
In conclusion, this baby did not have antenatal pyelectasis, but multicystic dysplastic right kidney and the kidney disappeared after birth (autonephrectomy).
Transverse view of the kidneys at 34 weeks showing the cyst on the right kidney