Autosomal dominant polycystic kidney disease with ectopic unilateral multicystic kidney: a case report

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary renal disorder and the fourth cause of death of end-stage renal disease. The disease has a prevalence of 1:400-1:1000 accounting for 10% of patients on dialysis. In most ADPKD patients, bilateral kidneys are similarly affected, with numerous fluid-filled cysts arising from different nephron segments. Only a few cases of ADPKD with ectopic unilateral multicystic kidney have been reported. It has been observed that the deterioration of their kidney function seemed to be quicker than their age- and sex-matched controls and siblings especially when the ectopic kidney is dysplastic.

CASE PRESENTATION

We report a case of a 46-year-old Ghanaian male patient who presented with left flank pain and hematuria with high BP and deranged renal function. Abdominal ultrasonography showed both kidneys to be larger than normal and had multiple cysts of varying sizes with the right kidney located in the right iliac fossa. Follow up Abdominopelvic computer tomographic scan (CT-Scan) without contrast showed enlarged kidneys with the renal parenchyma replaced by innumerable cyst of varying sizes. The right kidney was ectopically located in the right aspect of the pelvis. A diagnosis of ADPKD with right pelvic ectopic multicystic kidney was made. He was put on antihypertensives, analgesia for the left flank pain and to have follow up at the urology and nephrology departments.

CONCLUSION

In most ADPKD patients, bilateral kidneys are similarly affected. Only a few cases of ADPKD with ectopic unilateral multicystic kidney have been reported. It has been observed that the deterioration of their kidney function seemed to be quicker than their age- and sex-matched controls and siblings especially when the ectopic kidney is dysplastic.

Outcome of children with multicystic dysplastic kidney: Does involved side matter?

BACKGROUND

Multicystic dysplastic kidney (MCDK) is a common anomaly detected on antenatal ultrasound. We aimed to assess the profile of children with MCDK and to investigate whether the involved side has any effect on outcome.

METHODS

Thirty-nine patients with MCDK and 20 controls were enrolled. Patients who estimated glomerular filtration rate (eGFR) values over 90 mL/min/1.73 m2 were compared with controls. Comparison was made between the involved sides.

RESULTS

MKDB was right-sided in 20 (51.3%) and left-sided in 19 (48.7%) patients. 33.3% had additional urinary tract abnormality, 10.2% had systemic abnormality. 82% showed contralateral kidney enlargement. 48.7% involuted, 17.9% underwent nephrectomy. 35.8% suffered from urinary tract infection (UTI). 5.1% had renal scarring (RS). 30% developed microalbuminuria. 12.8% complicated with hypertension. 17.9% progressed to chronic kidney disease (CKD). Hypertension was independent risk factor for developing CKD. Blood pressure, cystatin C and urine microalbumin/creatinine levels were increased, and eGFR values were decreased in patients compared to controls. No significant difference was found between the two sides for rates of involution, UTI, RS, nephrectomy, and additional abnormality. Cystatin C levels were higher on the right than left sides (p = .033).

CONCLUSION

Children with MCDK predispose to renal deterioration even at normal eGFR values. Although cystatin C levels tended to increase in right-sided patients, the involved side seemed to have no significant effect on renal outcome. Hypertension was main determinant for progression to CKD in MCDK.

Neonatal multicystic dysplastic kidney with mass effect: A systematic review

INTRODUCTION

Multicystic Dysplastic Kidney (MCDK) is a common cause of palpable abdominal mass in a neonate, yet reports are few of resultant life-threatening extrinsic compression. This systematic review is the first to review all known neonatal MCDK cases complicated by external compression due to mass effect. Our aim is to foster communication about these unusual cases to inform management of future comparable cases.

METHODS

This systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medical Subject Headings (MeSH) were used to search PubMed through June 8, 2021 as follows: ((((Polycystic Kidney Diseases/complications [MeSH Terms]) OR (Multicystic Dysplastic Kidney/complications [MeSH Terms])) AND (Humans [MeSH Terms]) AND (Infant, Newborn [MeSH Terms]) AND (Case Reports [Publication Type]) AND (("multicystic dysplastic kidney") OR ("multicystic kidney")))) OR ((unusual respiratory distress in newborn [Title]) AND (kidney)) OR (large MCDK). Resulting papers were screened and included if they reported neonatal MCDK complicated by external compression by mass effect. Excluded papers lacked an MCDK diagnosis, a neonatal patient, or clear indication of mass effect. Salient data was extracted from each case for comparison.

RESULTS

Of 51 papers screened, seven met inclusion criteria, presenting eight neonatal MCDK patients exhibiting varied combinations of symptoms secondary to external compression, including respiratory distress, gastrointestinal obstruction, and contralateral ureteral obstruction. All eight cases, ultimately managed with neonatal nephrectomy, had positive outcomes. Unreported and undiagnosed cases are not included in this review, making it susceptible to publication bias.

CONCLUSIONS

Large neonatal MCDK is typically managed conservatively, however it can be complicated by external compression due to mass effect. In this scenario, nephrectomy is a reasonable and definitive treatment. Less invasive management options may exist, e.g., aspiration with sclerotherapy. Communication about exceptional cases like these should be encouraged even when outcomes are poor.

Renal function in children with a congenital solitary functioning kidney: A systematic review

INTRODUCTION

Abnormal renal development that results in lack of function or development of one of two kidneys is known as congenital solitary functioning kidney (CSFK). Two well characterized sub-categories of CFSK are unilateral renal agenesis (URA) and multicystic dysplastic kidney (MCDK). This systematic review sought to evaluate the change in renal function in children ≤18 years old with a CSFK as a result of URA or MCDK.

METHODS

A literature search in MEDLINE and Embase was conducted (1946 to July 13, 2020). All relevant articles were retrieved and evaluated based on pre-selected criteria by two independent researchers. Data was then extracted from variables of interest and conflicts were resolved by a third researcher. The primary outcome was renal function, and the secondary outcomes were proteinuria and hypertension.

RESULTS

Forty-five studies were included, of which 49% (n = 22) were retrospective and/or 58% (n = 26) were cohort studies. A combined total of 2148 and 885 patients were diagnosed with MCDK or URA, respectively. The proportion of children with worsened renal function at follow-up was found to be 8.4% (95% CI: 5.2%-13.4%). Among the studies reporting renal function as a group mean or median at follow-up, 84% (21/25) had a GFR/CrCl above 90 (mL/min/1.73  m²/ml/min). In terms of secondary outcomes, the proportion of children with proteinuria and hypertension was found to be 10.1% (95% CI: 6.9%-14.6%) and 7.4% (95% CI: 5.0%-10.9%), respectively.

CONCLUSION

The risk of developing proteinuria (10.1%), hypertension (7.4%), and/or worsened renal function (8.4%) for children with CFSK as a result of MCDK or URA is low. However, the level of evidence in the literature is weak. Further research is needed to identify the predisposing factors that may differentiate the small subset of children with CSFK at a higher risk of developing adverse renal outcomes.

Multicystic Dysplastic Kidney and Incontinentia Pigmenti: Coexistence of 2 Rare Diseases

Multicystic dysplastic kidney is a congenital kidney malformation consisting of multiple cysts of various sizes without a normal kidney morphology. Incontinentia pigmenti is a rare X-linked dominant genodermatosis, which is usually lethal in males, that presents clinically in 4 stages. Here, we report a case of multicystic dysplastic kidney with ureterovesical junction obstruction and incontinentia pigmenti. Coexistence of these two rare diseases may be a coincidental phenomenon or an association between the two may exist.

Prospective Evaluation of Kidney Disease in Joubert Syndrome

BACKGROUND AND OBJECTIVES

Joubert syndrome is a genetically heterogeneous ciliopathy associated with >30 genes. The characteristics of kidney disease and genotype-phenotype correlations have not been evaluated in a large cohort at a single center.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We evaluated 97 individuals with Joubert syndrome at the National Institutes of Health Clinical Center using abdominal ultrasonography, blood and urine chemistries, and DNA sequencing.

RESULTS

Patients were ages 0.6-36 years old (mean of 9.0±7.6 years old); 41 were female. Mutations were identified in 19 genes in 92 patients; two thirds of the mutations resided in six genes: TMEM67, C5orf42, CC2D2A, CEP290, AHI1, and KIAA0586. Kidney disease was detected in 30%, most commonly in association with the following genes: CEP290 (six of six), TMEM67 (11 of 22), and AHI1 (three of six). No kidney disease was identified in patients with mutations in C5orf42 (zero of 15) or KIAA0586 (zero of six). Prenatal ultrasonography of kidneys was normal in 72% of patients with kidney disease. Specific types of kidney disease included nephronophthisis (31%), an overlap phenotype of autosomal recessive polycystic kidney disease/nephronophthisis (35%), unilateral multicystic dysplastic kidney (10%), and indeterminate-type cystic kidney disease (24%). Early-onset hypertension occurred in 24% of patients with kidney disease. Age at ESRD (n=13) ranged from 6 to 24 years old (mean of 11.3±4.8 years old).

CONCLUSIONS

Kidney disease occurs in up to one third of patients with Joubert syndrome, most commonly in those with mutations in CEP290, TMEM67, and AHI1. Patients with mutations in C5orf42 or KIAA0586 are less likely to develop kidney disease. Prenatal ultrasonography is a poor predictor of kidney involvement in Joubert syndrome. Unilateral multicystic dysplastic kidney and autosomal recessive polycystic kidney disease-like enlarged kidneys with early-onset hypertension can be part of the Joubert syndrome kidney phenotype.

[Laparoscopic Nephrectomy in Infant with Diamond Blackfan Syndrome]

An 8-month-old girl with Diamond Blackfan syndrome and idiopathic neutropenia needed steroid therapy for anemia, but the left multicystic dysplastic kidney was often infected. We performed laparoscopic nephrectomy for infection control without any complications. Neutrocytes increased and the infection decreased after nephrectomy even with steroid therapy. Finally, she underwent bone marrow transplantation, as the anemia was not responding to steroid therapy.

Testicular cavernous hemangioma presenting as an ipsilateral lesion in a child with multicystic dysplastic kidney

Childhood malignant testicle tumors are very rare. In the literature to date, it has been reported that there are only 24 cavernous hemangioma cases existing in English literature. In this study, we discuss a testicular mass case which was diagnosed as cavernous hemangioma. The patient, who followed for left multicystic dysplastic kidney since his birth, was admitted to our clinic with complaints of left testicular mass and pain at 1-year of age. Histopathological investigation revealed cavernous hemagioma. Even if it has its characteristic ultrasonographic findings, radiology is too far beyond to eliminate the malignancy, final diagnosis can only be made after orchiectomy.

Renal dysplasia in Bardet-Biedl syndrome

BACKGROUND

Bardet-Biedl syndrome (BBS) is a multisystem genetic disorder characterized with central obesity, pigmentary retinopathy, polydactyly, mental retardation, and hypogenitalism. Renal abnormalities have been recognized as a cardinal feature of the disease with serious prognostic implication. The aim of this study was to analyze the renal status in children with BBS and to implement appropriate interventions in those with progressive course Patients and methods: The diagnosis of BBS was established on the basis of criteria proposed by Beales et al. (J Med Genet 1999). Imaging of the kidneys and urinary tract was performed with ultrasound study, Tc99(m)DMSA scan and a cystographic study. Twenty four hour urine collections were obtained for estimation of proteinuria and creatinine clearance. Blood pressure was monitored at clinical visits or as 24-hour ambulatory monitoring.

RESULTS

There were 4 children (2 males, 2 females). All four children displayed abnormal kidney ultrasound and Tc99(m)DMSA scan resembling dysplastic kidney(s). Two of them had overt proteinuria (glomerulo-tubular pattern). Three children had normal blood pressure and glomerular filtration rate (GFR): 107, 145 and 95 ml/min/1.73m(2), and the fourth had hypertension and progressive worsening of the GFR at 65 ml/min/1.73m(2).

CONCLUSION

Children with BBS should undergo imaging studies of the kidneys and urinary tract at initial work up; in those with renal dysplasia proteinuria, GFR and blood pressure should be regularly monitored to slow down progression to terminal renal failure.

Multicystic dysplastic kidney: is an initial voiding cystourethrogram necessary?

INTRODUCTION

Traditionally, a voiding cystourethrogram (VCUG) has been obtained in patients diagnosed with multicystic dysplastic kidney (MCDK) because of published vesicoureteral reflux (VUR) rates between 10%-20%. However, with the diagnosis and treatment of low grade VUR undergoing significant changes, we questioned the utility of obtaining a VCUG in healthy patients with a MCDK. We reviewed our experience to see how many of the patients with documented VUR required surgical intervention.

MATERIALS AND METHODS

We performed a retrospective review of children diagnosed with unilateral MCDK from 2002 to 2012 who also underwent a VCUG.

RESULTS

A total of 133 patients met our inclusion criteria. VUR was identified in 23 (17.3%) children. Four patients underwent ureteral reimplant (3.0%). Indications for surgical therapy included breakthrough urinary tract infections (2 patients), evidence of dysplasia/scarring (1 patient) and non-resolving reflux (1 patient). All patients with a history of VUR who are toilet trained, regardless of the grade or treatment, are currently being followed off antibiotic prophylaxis. To date, none have had a febrile urinary tract infection (UTI) since cessation of prophylactic antibiotics. Hydronephrosis in the contralateral kidney was not predictive of VUR (p = 0.99).

CONCLUSION

Routine VCUG in healthy children diagnosed with unilateral MCDK may not be warranted given the low incidence of clinically significant VUR. If a more conservative strategy is preferred, routine VCUG may be withheld in those children without normal kidney hydronephrosis and considered in patients with normal kidney hydronephrosis. If a VCUG is not performed the family should be instructed in signs and symptoms of urinary tract infection.

Horseshoe kidney with cysts and a single ureter: a case report

Horseshoe kidney is the most common of all renal fusion anomalies, occurring in approximately 0.25% of the general population. Horseshoe kidney with only a single ureter is a rare anomaly. A 60-year-old man was admitted to hospital for routine health screening. His family history was negative for kidney diseases, and there was no abnormality in his physical examination. A computed tomography (CT) scan revealed an atypical horseshoe kidney with cysts and three-dimensional spiral CT reconstruction showed the presence of a single ureter. The patient has since been followed up for two years without any signs of clinical disease. We report a rare case of a patient with a horseshoe kidney with cysts and a single ureter that was diagnosed incidentally.

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.

Is the risk of hypertension an indication for prophylactic nephrectomy in patients with unilateral multicystic dysplastic kidney?

OBJECTIVE

Surgery is still proposed by some as the treatment of choice for unilateral multicystic dysplastic kidney (UMCDK) because of the potential complications of hypertension, infection and malignant change. The purpose of this study is to demonstrate that the risk of hypertension does not justify routine nephrectomy.

MATERIAL AND METHODS

We report 41 cases of UMCDK, treated between 1980 and 2001, 28 of whom were male (68%). Twenty-one patients were nephrectomized (51%). Twenty patients (49%) underwent clinical and ultrasound follow-up. Blood pressure was controlled every 3-4 months (over a period ranging from 9 months to 6 years) and an ultrasound scan was performed every 6 months during the first 2 years, and annually thereafter.

RESULTS

In the patients treated non-operatively we observed a progressive spontaneous involution of their multicystic dysplastic kidneys and the total absence of complications such as hypertension or malignancy.

CONCLUSION

It is reasonable to conservatively manage patients with UMCDK by means of repeated ultrasound examinations and blood pressure control.

Follow-up of unilateral multicystic kidney dysplasia after prenatal diagnosis

OBJECTIVES

Since the introduction of antenatal diagnostic screening, multicystic kidney dysplasia (MCKD) has been diagnosed in 1 of 4300 live births. We analyze our own experience and demonstrate a management regime based on these results and existing studies.

METHODS

Retrospective data analysis was carried out in 110 patients, prenatally diagnosed with MCDK. A total of 93 patients with confirmed diagnosis of unilateral MCDK were born alive and followed up in our institutions.

RESULTS

A total of 110 unilateral cystic kidneys were prenatally diagnosed; 93 were confirmed postnatally. These children were retrospectively allocated to two treatment groups: 51 were operated upon; 42 were treated conservatively. A micturition cystourethrogram was performed 88 times, yielding 20 pathological findings. Vesicoureteral reflux was identified 11 times (12.5%). Eleven children (12%) had associated non-urological abnormalities. Cardiac and musculoskeletal malformations predominated. After 1995, nephrectomy was performed only when clinically indicated. Thirty-seven children were treated conservatively for between 4 months and 6 years (mean 33 months); 28 dysplastic kidneys exhibited size reduction. Complete involution was noted in 16 of 28 children between 7 and 29 months (mean 16.2 months).

CONCLUSION

This study provides evidence that neonatal nephrectomy of unilateral MCDK is rarely required. It also shows that the discussed malformation is not an isolated developmental abnormality. In a high proportion, associated urogenital abnormalities were present and therapeutically relevant, and determined the overall prognosis.

Simple multicystic dysplastic kidney disease: end points for subspecialty follow-up

Simple multicystic dysplastic kidney (MCDK) disease, defined as unilateral MCDK without other genitourinary tract involvement, portends an excellent prognosis. Nevertheless, its long-term management remains undefined. This study aims to provide subspecialty discharge recommendations for these patients. We identified eighty patients with simple MCDK disease by renal ultrasound between 1996 and 2006. Their charts were reviewed for growth of the contralateral kidney, involution of the MCDK, and incidence of complications, specifically hypertension, chronic renal insufficiency (CRI), urinary tract infection (UTI), and malignancy. Mean follow-up was 5 years. At approximately 1 year, 59% of unaffected kidneys were hypertrophied (>or=95th percentile for age/height) and 100% were >50th percentile. With continued follow-up, 80.3% of unaffected kidneys were hypertrophied. Likewise, at 1 year, 71.2% of MCDKs assessed were either involuting or had disappeared; on further follow-up, this increased to 89.6%. No patient had hypertension, CRI, or malignancy. Four patients (5%) developed nonrecurrent UTIs, none leading to renal scarring or growth impairment. These data suggest that subspecialty follow-up may be discontinued once contralateral hypertrophy and ipsilateral involution occur, assuming that the patient has not experienced hypertension, CRI, or UTI. These criteria are often met by 1 year of age, which would preclude repeated visits, uncomfortable investigations, and unnecessary costs.

[Spontaneous renal bleeding in a dialysis patient with acquired cystic disease of the kidney: case report and review of the literature]

The aim of this paper is to describe a rare clinical case of spontaneous haemorrhagic rupture of a multicystic kidney in a patient on haemodialysis for acquired cystic disease. We also discuss current issues about the management of this rare condition, with a short review of the literature.

Multicystic dysplastic kidney in association with congenital ichthyosiform erythroderma

Multicystic dysplastic kidney is a noninherited congenital disease. Association of this disease with abnormalities of various organs is common. We, however, report a rare case of multicystic dysplastic kidney associated with congenital ichthyosiform erythroderma in an infant. Different developmental origins of the skin and the kidney can explain the scarcity of concurrent congenital skin and kidney abnormalities. Nonetheless, the development of both organs depends on mesenchyme-epithelial interactions for inductive signaling. It seems defects in the production of signaling molecules can explain such an association.

Diagnosis of aortic coarctation by tardus-parvus renal artery Doppler signal in an infant with multicystic dysplastic kidney: a case report

We report an infant with known unilateral multicystic dysplastic kidney (MCDK) who underwent renal ultrasonography and Doppler spectral waveform analysis for investigation of hypertension. A tardus-parvus waveform was demonstrated in the renal artery on the normal side suggesting either renal artery or more proximal stenosis. Coarctation of the aorta was subsequently demonstrated.

Clinico-pathological profile of 22 cases of cystic renal dysplasia

Renal dysplasia is one of the major renal developmental anomaly characterized by abnormal structural organization and development of metanephric elements. It is usually detected antenatally or in early childhood. The kidney may be multicystic, aplastic, hypoplastic or duplex. We studied 22 cases of cystic renal dysplasia diagnosed over a period often years to identify the spectrum of morphological changes in dysplastic kidney, with special emphasis on mesenchymal changes. Clinical, radiological and gross morphologicalfeatures were noted. Microscopic features were studied in detail, including the epithelial and mesenchymal changes. Twenty-one of the 22 cases studied were children. One case was a 21-year-old adult, which is a rare age at presentation. Male to female ratio was 1.1:1. One of our patients had contra-lateral ureteric stenosis, a rare anomaly reported with renal dysplasia. Ten patients, all autopsy cases, had multi-system congenital anomalies. As cystic renal dysplasia is not a hereditary disease, it must be differentiated from polycystic kidney disease. Other differential diagnoses are cystic nephroma and cystic partially differentiated nephroblastoma. Histopathological examination is the final diagnostic tool since radiological features alone may not be sufficient to exclude other cystic renal lesions. Cartilage may not be seen in all cases of renal dysplasia. Once diagnosed, other associated anomalies should also be looked for.

Embryology and genetics of primary vesico-ureteric reflux and associated renal dysplasia

Congenital anomalies of the kidney and urinary tract, as well as primary vesico-ureteric reflux (VUR) and associated renal dysplasia, are the most relevant causes of end-stage renal failure in the pediatric population. In vivo and in vitro experimental studies have allowed the identification of several genes involved both in ureteric bud branching, ureteric elongation and insertion into the bladder, and in nephrogenesis. It has been proposed that both renal and ureteral abnormalities, as well as the associated renal hypo-dysplasia, may derive from a common mechanism as the result of a dysregulation of the normal developmental program. The large homologies between mice and the human genome suggest that the same genes could be involved both in rodent and human VUR. Furthermore, epidemiological observations suggest that not only syndromic but also isolated VUR is an inherited trait. Linkage analysis for homologous mouse genes in humans, genome-wide linkage studies in multigenerational families and association studies by polymorphisms support the hypothesis that VUR is genetically heterogeneous and is caused by a number of different genes acting with random environmental effects. The present teaching paper is an overview of the embryology and genetics of primary VUR and associated congenital reflux nephropathy.

Left-sided gastroschisis and bilateral multicystic dysplastic kidneys: a rare combination of anomalies

Left-sided gastroschisis is very rare. We report a case of left-sided gastroschisis associated with bilateral multicystic dysplastic kidneys. This combination of anomalies is unknown. The pathogenesis of gastroschisis is not well understood. It is now viewed as a malformation rather than disruption. The findings in this case support this view. The combination of dysplastic kidneys with ventral body wall defect suggests an early developmental defect.

Natural history of patients with multicystic dysplastic kidney-what followup is needed?

PURPOSE

Most clinicians recommend followup with annual ultrasound for patients with multicystic dysplastic kidney. The aim of this study was to determine whether followup ultrasound provides any clinical benefit.

MATERIALS AND METHODS

We retrospectively reviewed the charts of 73 patients who were diagnosed with multicystic dysplastic kidney between October 1991 and August 2005. Data were analyzed with respect to patient characteristics and followup information.

RESULTS

We identified 61 patients (43 boys and 18 girls) with adequate followup. A total of 49 patients (80%) were diagnosed prenatally and 12 (20%) postnatally. Associated urological anomalies were noted in 16 patients (26%). Median followup was 2.6 years (range 6 months to 37.5 years). Ultrasound examinations showed complete involution in 25 patients (41%) and partial regression in 18 (30%). The size of the multicystic dysplastic kidney increased in 1 patient (1.6%) and was unchanged in 17 (28%) without any pathological manifestations. Median age at complete involution was 2.1 years (range 36 days to 13.7 years). Patients with contralateral compensatory hypertrophy had more rapid complete involution. Urinary tract infection developed in 6 patients, of whom 1 was ultimately found to have reflux and 1 had ureteropelvic junction obstruction.

CONCLUSIONS

In our patients with unilateral multicystic dysplastic kidney ultrasound provided little clinically important information. Our data and a review of the literature suggest that once the diagnosis is made, no urological followup is needed. The primary care provider should monitor patients with multicystic dysplastic kidney for hypertension, abdominal mass and urinary tract infection.

Unilateral multicystic dysplastic kidney: long term outcomes

AIMS

To report the long term follow up of children with antenatally detected unilateral multicystic dysplastic kidney (MCDK) with documentation of complications, involution rate with time, and renal function at 10 years.

METHODS

Data were retrieved from a prospective regional registry of patients with MCDK between 1985 and 2004. Children were followed using a common protocol of investigation with follow up ultrasound scans (USS) at 2 (165 patients), 5 (117 patients), and 10 years (43 patients).

RESULTS

Serial USS showed that 33% of the MCDK kidneys had completely involuted at 2 years of age, 47% at 5 years, and 59% at 10 years. No patients developed hypertension, significant proteinuria, or malignancy, but two developed pelviureteric junction obstruction in the contralateral kidney. Twenty seven of 143 children (19%) had vesicoureteric reflux (VUR) (96% mild to moderate VUR) into the contralateral kidney with no difference in the incidence of urinary tract infections or renal scarring between those with or without VUR. The mean estimated glomerular filtration rate (GFR) was 86.4 ml/min/1.73 m2 (range 48-125) in 31 of 43 patients followed to 10 years.

CONCLUSIONS

Conservative management of unilateral MCDK is justified with clinical review and infrequent USS but longer term follow up continues in the 41% still with renal remnants at 10 years and those with impaired GFR. It is suggested that the initial micturating cystogram is deferred unless abnormal USS features are present in the contralateral kidney or ureter.

Malignant retroperitoneal tumor arising in a multicystic dysplastic kidney of a girl with Schinzel-Giedion syndrome

We report the first case of malignant retroperitoneal tumor arising in a multicystic dysplastic kidney of an 8-year-old girl with Schinzel-Giedion syndrome. Although conservative treatment has been regarded as the standard management for asymptomatic multicystic dysplastic kidney, prophylactic surgical removal should be considered for selected children with potential risk of malignancy.

Mutations in Uroplakin IIIA are a rare cause of renal hypodysplasia in humans

BACKGROUND

Renal hypodysplasia, characterized by a decrease in nephron number, small overall kidney size, and maldeveloped renal tissue, is a leading cause of chronic renal failure in young children. Familial clustering and renal hypodysplasia phenotypes observed in transgenic animal models suggest a genetic contribution. Uroplakin IIIa (encoded by UPIIIA) is an integral membrane protein present in urothelial plaques, and the murine UPIIIa knockout is associated with urothelial anomalies and vesicoureteral reflux. De novo UPIIIA mutations recently were identified in 4 of 17 patients with severe bilateral renal adysplasia.

METHODS

To evaluate the overall role of UPIIIA in human renal hypodysplasia pathogenesis, we performed UPIIIA mutation analysis in a cohort of 170 pediatric patients affected by severe unilateral or bilateral renal hypodysplasia. Eighty-one patients were affected by bilateral nonobstructive renal hypodysplasia; of these, 61 were without vesicoureteral reflux. Eighty-four patients presented with unilateral nonobstructive renal hypodysplasia, including 24 patients with unilateral multicystic dysplastic kidneys. Family history was positive in 11%.

RESULTS

Mutation analysis showed 2 heterozygous mutations not observed in 200 race-matched control chromosomes. In only 1 family was distribution of the UPIIIA mutation consistent with a disease-causing effect. This de novo missense mutation (Gly202Asp) was identified in a patient with unilateral multicystic dysplastic kidneys. The second (intronically located) mutation appeared unlikely to be disease causing because it did not segregate with an obvious disease phenotype in the affected family.

CONCLUSION

Our results indicate that de novo mutations in UPIIIA can be involved in defective early kidney development, but probably constitute only a rare cause of human renal hypodysplasia in a minor subset of individuals.

Multicystic dysplastic kidney with ipsilateral abnormalities of genitourinary tract: experience in children

OBJECTIVES

To investigate the incidence, nature, and management of associated ipsilateral genitourinary malformations in children with multicystic dysplastic kidney (MCDK).

METHODS

In this retrospective study, we analyzed the medical records and imaging studies of 93 patients with MCDK. Patients underwent ultrasonography, voiding cystourethrography, intravenous urography, and radionuclide renal imaging studies during their first month of age.

RESULTS

A diagnosis of MCDK associated with malformation of the ipsilateral internal genitalia was confirmed in 11 patients after birth investigations of prenatal MCDK. Three were diagnosed at 1, 12, and 14 years of age because of epididymitis, pelvic pain associated with amenorrhea, and accidentally during lumbar pain assessment, respectively. The male/female sex ratio was 10:4. The left side was involved in 9 patients. We had 3 cases of Gartner duct persistence, 6 of cystic retrovesical and laterovesical masses with vanishing MCDK, 4 of cystic retrovesical or laterovesical masses with compressive MCDK, and 1 of a blind-ending hemivagina. Nine patients were periodically observed, and four underwent nephroureterectomy. All patients underwent 6-month follow-up examinations with ultrasonography (mean follow-up 6.54 years, range 36 months to 14 years).

CONCLUSIONS

Of the 93 patients with MCDK, 14 (15%) had malformations of the ipsilateral internal genitalia. Persistence of seminal cysts in boys and Gartner ducts were encountered even if the MCDK had involuted. These results suggest that follow-up of patients with MCDK should be performed until the end of puberty to detect genitourinary malformations.

Segmental multicystic dysplasia and ureteropelvic junction obstruction in a nonduplicated kidney

A 2-month-old child presented for evaluation of prenatal hydronephrosis. Imaging studies were consistent with a right duplex system with a dysplastic, nonfunctioning upper pole and lower pole ureteropelvic junction obstruction. We proceeded with removal of the upper pole and pyeloplasty and were surprised to find a single collecting system with a cystic, dysplastic upper pole segment and the absence of an upper pole pelvis or ureter. The rare diagnosis of a segmental multicystic dysplastic kidney with ipsilateral ureteropelvic junction obstruction was made. We present a review of the case and of previous literature on this topic.

Distinctive collection of fetal anomalies: cleft lip and palate, multicystic dysplastic kidneys, 1-2 syndactyly, heterotopic olivary tissue and thymic hypoplasia

A female fetus with an unusual collection of congenital anomalies was detected prenatally. The pregnancy was terminated at 21 weeks of gestation. Clinical and pathological findings of bilateral cleft lip and palate, micrognathia, thymic hypoplasia, unilateral 1-2 finger syndactyly, bilateral multicystic dysplastic kidneys and heterotopic olivary tissue are presented. Differential diagnoses are discussed.

FGFR3 mutation in thanatophoric dysplasia type 1 with bilateral cystic renal dysplasia: coincidence or a new association?

Thanatophoric dysplasia (TD) is a lethal dwarfism condition due to missense mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. Examination of TD patients reveals mainly the involvement of the skeletal system and the brain, but also renal and cardiovascular anomalies have been described. We report the prenatal detection of TD type 1 (TD1) associated with bilateral cystic renal dysplasia (CRD) Potter's type II, in which the molecular analysis reveals the typical Arg248Cys substitution in the FGFR3 gene. CRD has not been previously described in TD or other conditions due to FGFR3 mutations, but occurs in Apert syndrome (due to FGFR2 mutations). The possible involvement of renal developmental defect in FGFR3 mutations is discussed.

Risk of hypertension with multicystic kidney disease: a systematic review

BACKGROUND

Children with multicystic kidney disease (MCKD) are increasingly managed conservatively, and are followed up throughout childhood because of the risk of hypertension highlighted in some reports. With this risk still poorly defined, the strategy and the duration of follow up do not seem to be based on evidence.

METHODS

Systematic review of the literature for all published cohort studies (prospective and retrospective) of children diagnosed to have unilateral MCKD and managed conservatively. Exclusion criteria were bilateral MCKD, and nephrectomy (not for hypertension) during the follow up period. For children with MCKD, the probability of developing hypertension during the follow up period was estimated.

RESULTS

From 29 reviewed studies, six cases of hypertension developed in 1115 eligible children. The mean probability of a child with unilateral MCKD developing hypertension was therefore 5.4 per 1000 (95% CI estimated at 1.9 to 11.7 per 1000).

CONCLUSION

Although the risk of hypertension in MCKD is low, the results of this study do not allow firm recommendations on the frequency and duration of blood pressure measurement follow up for these children. Large prospective cohort studies with a very long duration of follow up are needed.

Cross-fused ectopic multicystic dysplastic kidney with associated ureterocele

We describe a case of the unique congenital anomaly of cross-fused ectopic multicystic dysplastic kidney with associated ureterocele and demonstrate the usefulness of magnetic resonance imaging in fetal imaging.

GATA3 haploinsufficiency causes a rapid deterioration of distortion product otoacoustic emissions (DPOAEs) in mice

Human HDR (hypoparathyroidism, deafness and renal dysplasia)-syndrome is caused by haploinsufficiency of zinc-finger transcription factor GATA3. The hearing loss due to GATA3 haploinsufficiency has been shown to be peripheral in origin, but it is unclear to what extent potential aberrations in the outer hair cells (OHCs) contribute to this disorder. To further elucidate the pathophysiological mechanism underlying the hearing defect in HDR-syndrome, we investigated the OHCs in heterozygous Gata3-knockout mice at both the functional and morphological level. While the signal-to-noise ratios of distortion product otoacoustic emissions (DPOAE) in wild type mice did not change significantly during the first half-year of live, those in the heterozygous Gata3 mice decreased dramatically. In addition, both light microscopic and transmission electron microscopic analyses showed that the number of OHCs containing vacuoles was increased in the mutants. Together, these findings indicate that outer hair cell malfunctioning plays a major role in the hearing loss in HDR-syndrome.

Congenital ureteric strictures: an uncommon cause of antenatally detected hydronephrosis

Often misdiagnosed as primary megaureter or pelviureteric junction obstruction, congenital ureteral stenosis and valves are the main causes of congenital ureteric obstruction. We report three consecutive cases of congenital ureteric strictures presenting with antenatally diagnosed hydronephrosis. Two of our cases had a contralateral multicystic dysplastic kidney. We discuss the aetiology, clinical presentation, diagnostic evaluation, surgical management, and operative results as well as present an overview of the international literature, highlighting the importance of early referral in cases of contralateral abnormality as well as the importance of performing a retrograde study to facilitate the diagnosis and choice of incision.

Natural history of vesicoureteral reflux associated with kidney anomalies

OBJECTIVES

To evaluate the cystographic follow-up of patients with multicystic dysplastic kidney (MCDK), renal agenesis, and renal ectopia with associated primary vesicoureteral reflux (VUR).

METHODS

Patients with primary associated VUR (grade 2 or more) and with a minimal follow-up of 24 months were included in this study.

RESULTS

Of the children with renal agenesis, 24% had VUR. The median grade of VUR was significantly greater in the boys than in the girls (4 versus 2, respectively; P < 0.05). All girls and 34% of the boys experienced spontaneous resolution 1 year after diagnosis; 66% of the boys required operative treatment. Of the patients with MCDK, 16% had VUR. The median grade of VUR in the kidney contralateral to the MCDK was greater in the boys than in the girls (3.5 versus 2, respectively; P = 0.06). All girls and 60% of the boys had spontaneous resolution 1 year after diagnosis; 40% of the boys underwent operative treatment. Of the children with renal ectopia, 30% had VUR. The median grade of VUR for the refluxing unit was significantly greater in the girls than in the boys (3 versus 2, respectively; P < 0.05). Spontaneous resolution of VUR was observed in all boys (66% at 1 year) and in 40% of the girls; 60% of the girls required operative treatment.

CONCLUSIONS

Spontaneous resolution of VUR can be anticipated in girls with MCDK or renal agenesis and in boys with renal ectopia. These data can be used in planning the proper follow-up schedule for babies with a kidney anomaly detected by ultrasonography.

Missed testis on laparoscopy despite blind-ending vessels and closed processus vaginalis

Laparoscopy has become a preferred technique to evaluate a nonpalpable testis. It gives excellent visualization of the anatomy to differentiate a viable or absent testis. We present a case of an intra-abdominal testis that was missed on diagnostic laparoscopy. Despite a closed processus vaginalis, an absent vas deferens, and blind-ending vessels above the internal ring, the testis was missed.