Prenatal Evaluation and Postnatal Follow-Up of Ureteral Ectopic Insertion in Multicystic Dysplastic Kidneys.

<bold>Objective: </bold>To emphasize the need for analyzing the pelvis when a unilateral multicystic dysplastic kidney (MCDK) is observed at prenatal ultrasonography (US) because of possible associated ectopic ureteral insertion.<bold>Methods: </bold>We performed a retrospective study including prenatal US diagnosis of unilateral MCDK and retrovesical cyst. The following data were recorded: pre- and postnatal US, magnetic resonance imaging (MRI), and voiding cystourethrography (VCUG) findings. The shape of the pelvic cyst was analyzed as well as the visibility of the ureteral insertion into the cyst.<bold>Results: </bold>Fourteen patients were included (7 females). At prenatal US, the cyst wall was smooth in 8 cases (6 females) and lobulated in 5 cases (4 males). In 1 case it protruded into the bladder. Ectopic ureteral insertion was observed in 2 cases. Prenatal MRI (n = 6) depicted ureteral insertion in 2 more cases. Postnatal US (n = 14) showed the same cyst patterns as prenatally, ectopic ureteral insertion (n = 8), and duplicated uterus (n = 4). Postnatal MRI (n = 7) always depicted the ureteral ectopic insertion into the cyst. VCUG (n = 5) showed indirect findings of ectopic ureteral insertion (n = 3).<bold>Conclusion: </bold>Unilateral MCDK should lead to search for a retrovesical cyst corresponding most commonly to a distended hemivagina or a seminal vesicle. Early diagnosis of this condition leads to better clinical management. [ABSTRACT FROM AUTHOR]