Prenatal diagnosis and obstetrical management of multicystic dysplastic kidney disease

A Case of Multicystic Dysplastic Kidney Presenting as a Single Midline Pelvic Cyst

We present an unusual case of a female neonate presenting with a single midline pelvic cyst. Prenatal imaging was suggestive of multicystic dysplastic kidney (MCDK), but postnatal imaging was atypical for this diagnosis given the location and singular cyst noted. The patient ultimately underwent surgical exploration and was diagnosed with an ectopic MCDK. Ectopic MCDK should be considered in the differential diagnosis of unilocular cystic pelvic lesions identified in the perinatal period.

Diagnostic accuracy of midtrimester antenatal ultrasound for multicystic dysplastic kidneys

OBJECTIVES

To establish the diagnostic accuracy of obstetric ultrasound at a tertiary fetal medicine center in the prenatal detection of unilateral and bilateral multicystic dysplastic kidney (MCDK) in fetuses in which this condition was suspected, and to undertake a systematic review of the relevant literature.

METHODS

This was a retrospective observational study of all cases referred to a regional tertiary fetal medicine unit due to suspicion of either unilateral or bilateral MCDK between 1997 and 2015. Diagnosis was confirmed by postnatal ultrasound reports or postmortem examination. The accuracy of prenatal ultrasound in the diagnosis of MCDK was calculated. Using a systematic search strategy we also performed a review of the literature regarding the prenatal diagnosis and diagnostic accuracy of MCDK.

RESULTS

We included 144 women in our analysis; 37 (25.7%) opted for pregnancy termination (TOP) (due to unilateral MCDK with additional abnormalities, suspected bilateral MCDK or severe obstructive uropathy). Complete pre- and postnatal data were available in 126 pregnancies, including 104 livebirths, 19 TOPs with postmortem findings available and three intrauterine fetal deaths. Two infants died shortly after birth (due to known bilateral MCDK or known cranial vault defect). The overall number of cases of MCDK confirmed postnatally was 100; of these, 98 were diagnosed prenatally (true positive), while two were thought to be hydronephrosis prenatally (false negative) and the diagnosis of MCDK was made after birth. In nine cases, the initial antenatal diagnosis of suspected MCDK was revised, either later in pregnancy (n = 2) or postnatally (n = 7) (false positive). Overall, the diagnostic accuracy in our population for the use of antenatal ultrasound to detect MCDK was 91.3%, while that reported in the existing literature was found to range from 53.3% to 100%. MCDK was isolated in the majority (71%) of cases, while in 29% of cases it was found to be associated with other renal and extrarenal fetal abnormalities.

CONCLUSIONS

Antenatal ultrasound had a diagnostic accuracy of about 91% in the prediction of postnatal MCDK and can therefore be used to guide antenatal counseling. However, prenatal or postnatal revision of the diagnosis occurred in about 7% of cases and parents should be counseled appropriately. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Multicystic dysplastic kidney disease presenting with a single large cyst in a fetus-anatomical basis and radiological aspects

Multicystic dysplastic kidney (MCDK) is a congenital maldevelopment in which the renal cortex is characteristically replaced by numerous cysts of multiple sizes. MCDK presenting as a single predominant large cyst in morphology is less common. We report on the prenatal imaging findings and perinatal management of a fetus with MCDK unusually presenting as a single predominant large cyst, erroneously interpreted as a severe fetal hydronephrosis. Details of the perinatal history, radiological evaluation, morphological characteristic, and clinical aspect of this case are presented. We also discuss a few studies addressing the sensitivity of magnetic resonance urography for the prenatal diagnosis of MCDK.

Malignant rhabdoid tumor of the kidney combined with multicystic dysplasia in a 5-year-old child

Multicystic dysplastic kidney (MCDK) is a relatively common developmental anomaly in infants and children and has a good prognosis. In contrast, a malignant rhabdoid tumor of the kidney (MRTK) is one of the most lethal neoplasms of early life. However, the presentation of such a lethal tumor combined with multicystic dysplasia has not been reported to date. In this report, we describe a case of MRTK in a 5-yr-old girl who also had multicystic dysplasia. She was previously diagnosed with MCDK at birth due to a huge palpable mass on the right side of the abdomen. The right kidney was extensively replaced by numerous grossly dilated, variable-sized cysts. Microscopically, the tumor cells show a diffusely infiltrative growth pattern, which revealed large non-cohesive, round-to-polygonal tumor cells with vesicular nuclei. Some tumor cells had eccentric nuclei and large, round, eosinophilic cytoplasmic inclusions. There were metanephrons present, with the central ureteric bud and peripheral branches surrounded by condensing mesenchyma, immature glomeruli, and metaplastic cartilage in the adjacent parenchyma. To our knowledge, this is the first combined case of the two aforementioned diseases and this case may, in fact, suggest a new disease entity.

Prenatal diagnosis of apparently isolated unilateral multicystic kidney: implications for counselling and management

Cases where initial prenatal diagnosis was made of isolated unilateral multicystic kidney (UMCK) were reviewed to determine appropriate counselling and management strategies. For the 73 cases, chromosome abnormalities, pregnancy complications and family histories were reviewed. In addition, subsequently diagnosed birth defects, and pediatric medical and surgical outcomes were available for 54 cases. Of those with outcome information available renal/genital-urinary tract abnormalities were diagnosed subsequently in 33% and non-renal abnormalities in 16% of cases. Of the non-renal abnormalities, congenital heart defects were most frequent (7%). One chromosome abnormality, a trisomy 21, was present among 32 cases where karyotypes were known (3%). Amniotic fluid volume abnormalities were present in 11 cases but not predictive of associated anomalies, with the exception of one case where polyhydramnios accompanied multiple malformations consistent with VATER association. A family history of structural renal anomalies was reported in 11 cases (20%). There were 14 cases of partial or complete involution (25%), including two cases of complete prenatal involution of the cystic kidneys. No long-term associated morbidity such as hypertension or malignancy was present in our cohort. Based on our study and corroborating literature, amniocentesis should be offered to women when a seemingly isolated UMCK is detected on routine prenatal ultrasound. Furthermore, a detailed ultrasound with careful assessment of the fetal heart and contralateral kidney is indicated at diagnosis and during the third trimester to assess for further evidence of structural abnormalities, as well as amniotic fluid volume abnormalities. Careful assessment of the newborn is indicated with appropriate speciality referral as required.

Prenatal diagnosis and management of abnormalities in the urologic system

We have reviewed the prenatal diagnosis and management of abnormalities in the urologic system. Urologic anomalies may be caused by embryologic aberrations, genetic disease, or a nonrandom association with other structural abnormalities. There is a wide range of prognoses, depending on the cause and the impact of the anomaly on the production of amniotic fluid. Management focuses on obtaining an accurate prenatal diagnosis, providing appropriate counseling, and ensuring the proper surveillance or treatment before and after birth.

Prenatal collapse of cysts in a dysplastic kidney

Postnatal regression of prenatally or neonatally detected multicystic dysplastic kidney disease has been widely documented. However, renal cysts can regress during gestation, although they usually become larger in utero. We present a case of prenatally detected multicystic dysplastic kidney with an atypical course. During the third trimester, unilateral multicystic renal lesions in the fetus first enlarged and later involuted; by the second postpartum year, the kidney had become hypoplastic and nonfunctional. Our case also shows that before birth, blood flow in the affected kidney, measured with Doppler imaging, was normal until the cysts involuted.

Insights into the pathogenesis and natural history of fetuses with multicystic dysplastic kidney disease

To better delineate the natural history of multicystic displastic kidney disease (MCDKD) and provide insights into the pathogenesis of this condition, we report our experience in 102 prenatally detected cases. MCDKD is most commonly an incidental finding on prenatal ultrasound examination. The abnormality may be unilateral (76 per cent) or bilateral (24 per cent). In unilateral cases, abnormality of the contralateral kidney is common (33 per cent). Associated non-renal abnormalities occur frequently with both unilateral (26 per cent) and bilateral (67 per cent) MCDKD, and increase the risk for an abnormal chromosome study. Males are more likely to be affected than females with a ratio of 2.4:1, but females are twice as likely to have bilateral MCDKD and associated non-renal abnormalities, and four times more likely to have an abnormal chromosome study. We suggest that the option of chromosomal analysis should be discussed with all patients diagnosed with MCDKD in their fetus, if there is bilateral renal involvement or if an associated non-renal abnormality is present. Unilateral MCDKD without associated renal or non-renal abnormalities was not associated with an abnormal chromosome study, and resulted in favourable outcomes. While unilateral MCDKD, lack of associated anomalies, normal chromosome study and adequate amniotic fluid are all reassuring findings, a complete neonatal urologic work-up should be performed in all newborns. We believe the evaluation should include voiding cystourethrography to rule out vesicoureteral reflux. Our findings allow more precise counselling of patients regarding prognosis, and subsequent management of the fetus found to have MCDKD.

Clinical outcome of fetal uropathy. II. Sensitivity of echography for prenatal detection of obstructive pathology

Among 8,579 neonates born between February 1, 1981 and March 31, 1987, and cleared by prenatal sonography for significant urinary tract abnormality 158 subsequently were hospitalized because of signs or symptoms of urinary tract disease, predominantly urinary tract infection. Evaluation of these 158 patients revealed 24 with vesicoureteral reflux, 7 with duplicated systems (2 of which showed reflux), 1 with the syndrome of Fraley, 1 with pyelectasis and 5 with mild hydronephrosis (3 secondary to reflux and 2 with diethylenetriaminepentaacetic acid renal scans considered to be nonobstructed). There was no incidence of significant obstructive uropathy that had been missed by the previous prenatal sonography and that surfaced subsequently to cause morbidity in this series. The principal disorder of the urinary tract that may fail prenatal investigation is vesicoureteral reflux.

Clinical outcome of fetal uropathy. I. Predictive value of prenatal echography positive for obstructive uropathy

Clinical followup was performed in 73 neonates with a prenatal echographic suspicion of uropathy. Of 42 patients with a prenatal suspicion of unilateral hydronephrosis only 15 had pathological obstruction and 2 had multicystic dysplastic kidneys. Among 10 infants with a prenatal suspicion of bilateral hydronephrosis only 1 had true bilateral obstruction and 2 had unilateral obstruction. In 2 patients hydroureteronephrosis seen on prenatal echography was due to massive bilateral vesicoureteral reflux. In this group there was also a multicystic dysplastic kidney and 1 patient with bilateral cystic dysplasia. There was a prenatal suspicion of cystic disease in 8 infants. Postnatally, diagnosis was multicystic dysplastic kidney in 2 patients and a simple renal cyst in 4. The remaining 2 neonates had obstructive uropathy. Finally, of 13 neonates with a prenatal suspicion of anatomical-echo-structural abnormalities a definitive abnormality could be established in only 8. The predictive value of prenatal echography positive for obstructive uropathy was 34.6%.

Multicystic dysplastic kidney: natural history of prenatally detected cases

To delineate the natural history of fetal multicystic dysplastic kidneys (MDKs), all cases that were prenatally detected in the Prenatal Diagnosis Center of the University of Virginia from September 1985 to 31 August 1988 were reviewed. All patients were followed through the Center with serial ultrasound evaluations at approximately 4-week intervals, and each liveborn infant was evaluated and followed by one of the authors (S.S.H.). Of the 14 cases detected, ten were detected in the second trimester, the earliest at 16.5 weeks' gestation. Of the nine fetuses with non-lethal disease, there were two cases in which the lesion remained unchanged during observation. Both had an initial diagnosis in the third trimester. In those cases diagnosed in the second trimester (7), all showed an initial increase in the size and number of cysts, followed by involutional changes either in utero (2) or in the neonatal period (3). Two infants had immediate surgical removal of the MDK, one because of respiratory compromise, and the other because of an uncertain diagnosis on renal scan. Abnormalities of the contralateral kidney were found in 7 of 14 fetuses. Five were lethal conditions. Associated non-renal abnormalities were common in bilateral MDK (80 per cent), but rare in unilateral MDK (11 per cent).

Anatomic correlates of ultrasound prenatal diagnosis of urinary tract abnormalities

In 52 fetuses, in utero sonographic diagnosis of urinary tract malformations was correlated with their autoptic or surgical findings. 39 malformations were correctly diagnosed prenatally, although 5 other extrarenal-associated anomalies were not detected; 10 diagnoses were incomplete; in 3 cases the characteristics of malformations found at sonography turned out to be different at the post-mortem examination. The following factors impaired sonographic diagnoses: limited number of examinations, gestational age at the time of examination, nature of malformation and, above all, oligohydramnios (which is common in most urinary tract malformations). The correlations between renal malformations and karyotype anomalies are also discussed in relation to the higher incidence present in polymalformative syndromes.

Cystic renal disease and cardiovascular anomalies

Renal cysts are a relatively common but heterogeneous group of disorders that are increasingly being diagnosed prenatally. Prognosis depends on the type of cystic disease, extent of involvement, and the presence or absence of other anomalies. Czeizel (American Journal of Medical Genetics [Supplement] 2:17-21, 1986) indicated that a cystic kidney-cardiovascular malformation association exists. To investigate this further a population based study of renal cysts and associated anomalies in Manitoba children born between 1979 and 1983 was carried out. A total of 46 children with renal cysts were identified from multiple sources (1 per 1,824 total births). The most common types were multicystic dysplasia (1/3,226), cystic dysplasia due to lower urinary tract obstruction (1/13,932), and infantile polycystic kidney disease (1/20,973). Other anomalies were seen in 72% of cases and 33% had cardiovascular anomalies. A further 11% had patent ductus arteriosus or single umbilical artery. The incidence of cardiovascular defects excluding patent ductus arteriosus or single umbilical artery was 1/174 in the total birth cohort and our data confirmed a strong association of renal cysts with cardiovascular defects in children with malformations (P less than 0.001). The association of cardiac defects with unilateral multicystic dysplasia is especially important. Of the 14 children ascertained with unilateral dysplasia, 4 (28%) had major cardiac defects leading to early death in all instances. Only one of the 4 had additional defects. Unilateral multicystic dysplasia with a normal contralateral kidney usually has a good prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)