Renal dysgenesis and cystic disease of the kidney: a report of the Committee on Terminology, Nomenclature and Classification, Section on Urology, American Academy of Pediatrics

Maternal periconceptional folic acid supplementation and risk for fetal congenital genitourinary system defects

BACKGROUND

Taking folic acid supplementation could reduce the risk of neural tube defects for offspring in the maternal periconceptional period, but the relationship between folic acid use and other birth defects remains unclear, such as genitourinary system birth defects.

METHODS

The data from a Prenatal Health Care System and Birth Defects Surveillance System in Tongzhou, Beijing, China, were collected from 2013 to 2018. We adjusted for differences in characteristics between comparison groups using propensity score inverse probability weighting and assessed associations with Poisson regression modeling.

RESULTS

A total of 65,418 live births and stillbirths were included, and there were 194 cases with congenital genitourinary defects among them. The prevalence of genitourinary system birth defects was 29.2 (34.9) per 10,000 for FA/MMFA users (nonusers). Compared to nonusers, FA/MMFA users had a lower risk for genitourinary system birth defects (adjusted risk ratio [aRR] 0.81, 95% confidence interval [CI] 0.67, 0.98), and for hypospadias (aRR 0.55, 95% CI 0.40, 0.76).

CONCLUSIONS

FA or MMFA supplementation during the maternal periconceptional period could reduce the risk for genitourinary system birth defects in offspring. More mechanisms should be explored for the protective effect.

IMPACT

Folic acid (FA) or multiple micronutrients containing folic acid (MMFA) supplementation during the maternal periconceptional period could reduce the risk for genitourinary system birth defects in offspring. Maternal FA/MMFA supplementation during the periconceptional period may reduce the risk for hypospadias.

Localized cystic disease of the kidney in pediatric patients: Clinical and imaging findings with long term follow up

INTRODUCTION

This study aimed to describe the clinical and imaging findings, including ultrasonography (US) findings, and long-term follow-up results in pediatric patients with localized cystic disease of the kidney (LCDK).

MATERIAL AND METHODS

Retrospective review of pediatric patients diagnosed with LCDK based on imaging findings showing multiple localized renal cysts with intervening normal renal parenchyma from January 2002 to August 2020. Clinical presentations and US features of the affected and contralateral kidneys were reviewed and compared with computed tomography or magnetic resonance imaging findings, if available.

RESULTS

A total of 18 patients (male:female = 11:7; median age, 8 years) were included. Initial clinical presentations were incidental findings (n = 5), abdominal pain (n = 5), or hematuria (n = 5). Of the seven patients (7/18, 39%) who showed multiple hyperechoic foci with ring-down artifacts within the cystic lesions on US, six patients showed focal calcification of the cysts on CT. Two patients (2/18, 11%) had milimetric cysts in the contralateral kidney. During follow-up (range, 2-122 months), there was an increase in lesion size, with ipsilateral renal growth in four patients (4/18, 22%). There was no renal function impairment at the initial presentation or during follow-up in all patients.

CONCLUSIONS

LCDK can present with milimetric calcifications (39%), contralateral milimetric renal cysts (11%), and mild size increase during renal growth (22%) in children without renal function impairment. Follow-up US is recommended without surgical intervention in these typical cases.

Renal Hypoplasia, From Grossly Insufficient to Not Quite Enough: Consideration for Expanded Concepts Based Upon the Author's Perspective With Historical Review

Hypoplasia is defined in the Merriman-Webster dictionary as "a condition of arrested development in which an organ, or part, remains below the normal size, or in an immature state." The degree of reduced size is not definitional. Renal hypoplasia, however, has historically been defined as a more marked reduction in renal mass such that presentation in childhood is the norm. There are 3 commonly recognized types of renal hypoplasia, simple hypoplasia, oligomeganephronic hypoplasia (oligomeganephronia) and segmental hypoplasia (Ask-Upmark kidney). They have in common a reduction in the number of renal lobes. A fourth type, not widely recognized, is cortical hypoplasia where nephrogenesis is normal but there is a reduction in the number of nephron generations. Recently there has been great interest in milder degrees of reduced nephron mass, known as oligonephronia because of its association with risk of adult-onset hypertension and chronic kidney disease. Since the last pathology review of this topic was published by Jay Bernstein in 1968, an update of the renal pathology findings in renal hypoplasia is provided with a review of 18 new cases. The renal hypoplasias are then framed within the modern concept of oligonephronia, its diverse causes and prognostic implications.

Ureteral tumor in an ectopic duplex system: a case report

INTRODUCTION

Ureteral ectopia is a rarely observed anomaly. It may be totally asymptomatic. An association with a duplex system is exceptional. Diagnostic and therapeutic approaches are challenging. Carcinologic surgery must consider the anatomic variant, mainly related to the ectopic site of the ureteral orifice.

OBSERVATION

We report a case of a ureteral urothelial carcinoma in a North African 52-year-old male patient, in a right duplex system. Radiological explorations concluded a non-functional upper right kidney. A suspect mass was observed in the lumbar part of the ureter of the right upper system. The meatus of the tumorous ureter ended in the right lobe of the prostate. A right hemi-nephro-ureterectomy was performed. A histological examination concluded a pT2G2 urothelial carcinoma.

CONCLUSION

Even if malignancy is rarely observed in ureteral ectopia, it should be evoked mainly in cases of hematuria with risk factors for urothelial tumors.

Urologic Diseases Germane to the Medical Renal Biopsy: Review of a Large Diagnostic Experience in the Context of the Renal Architecture and Its Environs

The kidney is one of the most complicated organs in development and is susceptible to more types of diseases than other organs. The disease spectrum includes developmental and cystic diseases, involvement by systemic diseases, iatrogenic complications, ascending infections and urinary tract obstruction, and neoplastic diseases. The diagnosis of kidney disease is unique involving 2 subspecialties, urologic pathology and renal pathology. Both renal and urologic pathologists employ the renal biopsy as a diagnostic modality. However, urologic pathologists commonly have a generous specimen in the form of a nephrectomy or partial nephrectomy while a renal pathologist requires ancillary modalities of immunofluorescence and electron microscopy. The 2 subspecialties differ in the disease spectrum they diagnose. This separation is not absolute as diseases of one subspecialty not infrequently appear in the diagnostic materials of the other. The presence of medical renal diseases in a nephrectomy specimen is well described and recommendations for reporting these findings have been formalized. However, urologic diseases appearing in a medical renal biopsy have received less attention. This review attempts to fill that gap by first reviewing the perirenal anatomy to illustrate why inadvertent biopsy of adjacent organs occurs and determine its incidence in renal biopsies followed by a discussion of gross anatomic features relevant to the microscopic domain of the medical renal biopsy. Unsuspected neoplasms and renal cysts and cystic kidney diseases will then be discussed as they create a diagnostic challenge for the renal pathologist who often has limited training and experience in these diseases.

Segmental multicystic dysplastic kidney in children: clinical presentation, imaging finding, management, and outcome

PURPOSE

The aim of the study was to assess the presentation, imaging findings, management, and outcome of segmental multicystic dysplastic kidney (MCDK) in children.

MATERIALS AND METHODS

Six patients with segmental MCDK were diagnosed and observed at our hospital. We reviewed the medical records to collect data on initial symptoms, results of imaging studies, associated urinary tract anomalies, operation, and outcome.

RESULTS

Three patients had abnormal prenatal ultrasound and were diagnosed by further postnatal imaging; they were asymptomatic after birth. The other 3 children presented with a renal mass, recurrent urinary tract infection, or urinary incontinence. Five patients had associated ipsilateral or contralateral urinary tract abnormalities, including vesicoureteral reflux, ureterocele, duplex collecting system, ureteropelvic junction stenosis, and ectopic ureter. Lower tract reconstruction was performed in 3, and open biopsy was done in 1 child. None underwent partial or total nephrectomy, and all had involution of the cysts for a mean of 40 months.

CONCLUSIONS

Most of the cases occur in the upper pole of a duplex kidney and often involute spontaneously without significant complication. The clinical presentation and imaging findings depend on the associated anomalies and complications. Although the latter may require surgery to resolve, segmental MCDK itself rarely requires resection.

The classification of renal cystic diseases and other congenital malformations of the kidney and urinary tract

CONTEXT

Renal cystic diseases and congenital abnormalities of the kidney and urinary tract comprise a heterogeneous group of lesions whose pathogenesis has eluded physicians for centuries. Recent advances in molecular and genetic understanding of these diseases may provide the solution to this riddle.

OBJECTIVE

The formulation of an effective classification system for these disorders has been elusive but is needed to introduce order while providing a conceptual framework for diagnosis.

DATA SOURCES

This review discusses the evolution, beginning in the 19th century, of postulates regarding the pathogenesis of cystic and developmental renal diseases. Selected classification systems proffered during this period are discussed in pursuit of an ideal classification schema that would account for morphologic features and their clinical importance, with logical links to pathogenesis and treatment. Although this remains an elusive target, its general outline is becoming clearer. A classification approach favored by the author is presented, which incorporates many of the strengths contained in several previous classifications.

CONCLUSIONS

Genetic-and molecular-based postulates regarding the pathogenesis of the renal cystic and developmental diseases have implicated mutated master genes and the modification of genes that are crucial in renal development and genes that are central to the sensory effects of the renal tubular primary cilium on cell physiology. These scientific advances provide pathogenetic links between morphologically and genetically distinct entities and certain cystic and neoplastic entities, associations that seemed implausible not long ago. These advances may eventually provide the basis for future classification systems while suggesting targets for therapeutic approaches in the prevention and treatment of these diseases.

Deficiency in Six2 during prenatal development is associated with reduced nephron number, chronic renal failure, and hypertension in Br/+ adult mice

The Br/+ mutant mouse displays decreased embryological expression of the homeobox transcription factor Six2, resulting in hertitable renal hypoplasia. The purpose of this study was to characterize the renal physiological consequences of embryonic haploinsuffiency of Six2 by analyzing renal morphology and function in the adult Br heterozygous mutant. Adult Br/+ kidneys weighed 50% less than those from wild-type mice and displayed glomerulopathy. Stereological analysis of renal glomeruli showed that Br/+ kidneys had an average of 88% fewer glomeruli than +/+ kidneys, whereas individual glomeruli in Br/+ mice maintained an average volume increase of 180% compared with normal nephrons. Immunostaining revealed increased levels of endothelin-1 (ET-1), endothelin receptors A (ET(A)) and B (ET(B)), and Na-K-ATPase were present in the dilated renal tubules of mutant mice. Physiological features of chronic renal failure (CRF) including elevated mean arterial pressure, increased plasma creatinine, and dilute urine excretion were measured in Br/+ mutant mice. Electron microscopy of the Br/+ glomeruli revealed pathological alterations such as hypercellularity, extracellular matrix accumulation, and a thick irregular glomerular basement membrane. These results indicate that adult Br/+ mice suffer from CRF associated with reduced nephron number and renal hypoplasia, as well as glomerulopathy. Defects are associated with embryological deficiencies of Six2, suggesting that proper levels of this protein during nephrogenesis are critical for normal glomerular development and adult renal function.

Magnetic resonance urography in children

Magnetic resonance (MR) urography is a powerful tool that fuses anatomic information with functional data in a single test without the use of ionizing radiation. This article provides an overview of the technical aspects of MR urography and common clinical applications, such as the evaluation of hydronephrosis, reflux nephropathy, and renal dysplasia.

Misexpression of Six2 is associated with heritable frontonasal dysplasia and renal hypoplasia in 3H1 Br mice

A radiation-induced mouse mutant, Brachyrrhine (Br), exhibits frontonasal dysplasia and renal hypoplasia, two malformations associated with deficiencies in mesenchymal condensation. The purpose of this study was to resolve the Br locus, evaluate possible candidate genes, and identify developmental defects in the mutant chondrocranium. Linkage analysis mapped the Br mutation to a critical region distal to D17Mit76, which contains only one gene, the transcription factor Six2. Sequence analysis of the Six2 gene, including 1.5 kb of the promoter, failed to reveal the Br mutation. However, homozygous Br/Br embryos showed almost complete absence of Six2 mRNA and protein in craniofacial and renal tissues while heterozygous Br/+ embryos displayed intermediate Six2 levels. Mutant embryos displayed malformations of neural crest-derived structures of the anterior cranium where Six2 is normally expressed. These data suggest a mutation in a novel cis-acting regulatory region inhibits Six2 expression and is associated with frontonasal dysplasia and renal hypoplasia.

Evaluation of reflux nephropathy, pyelonephritis and renal dysplasia

MR urography has the potential to significantly improve our understanding of the relationship between reflux nephropathy, pyelonephritis, vesicoureteric reflux and renal dysplasia. MR urography utilizes multiple parameters to assess both renal anatomy and function and provides a more complete characterization of acquired and congenital disease. Pyelonephritis and renal scarring can be distinguished by assessing the parenchymal contours and signal intensity. Characteristic imaging features of renal dysplasia include small size, subcortical cysts, disorganized architecture, decreased and patchy contrast enhancement as well as a dysmorphic pelvicalyceal system. Because of its ability to subdivide and categorize this heterogeneous group of disorders, it seems inevitable that MR urography will replace DMSA renal scintigraphy as the gold standard for assessment of pyelonephritis and renal scarring. MR urography will contribute to our understanding of renal dysplasia and its relationship to reflux nephropathy.

Are therapeutic stem cells justified in bilateral multicystic kidney disease? A review of literature with insights into the embryology

Aim was to describe the challenges faced in the management of bilateral multicystic kidney disease (MCKD). A case of antenatally detected bilateral polycystic disease was referred at 28 weeks of gestation. The patient was advised to continue pregnancy till term and be in regular follow-up. Postnatally, the male baby passed urine in normal stream and was diagnosed as bilateral multicystic kidney disease on ultrasonography. He developed symptoms of renal failure. The baby was operated with right pyeloplasty and left pyelostomy, as the left ureter was atretic. The histopathology was consistent with bilateral multicystic kidney disease. Postoperatively, the baby was stable with intermittent episodes of metabolic acidosis that were managed medically and with peritoneal dialysis. Autologous stem cells were injected at the age of 1 year into the aorta at the level of the renal arteries clamping the aorta below. Repeat biopsy at time of stem cell injection showed 5/10 glomeruli showing global sclerosis on right side and 5/15 glomeruli showing global sclerosis on left side. The only improvement seen was in decreased doses of medicines to keep the child metabolically stable. The baby kept struggling but succumbed at the age of 17 months and 15 days. Post mortem bilateral renal biopsies demonstrated presence of primitive renal tubules and blastemal cells that were not demonstrated earlier. Survival for few months in bilateral multicystic kidney disease is thus possible with adequate treatment, the novel use of stem cells in these cases may prove beneficial in future though it is too early to comment further.

Renal papillary adenoma—a putative precursor of papillary renal cell carcinoma

The precursor lesions of renal cell carcinoma (RCC) are unknown. The purpose of this study is to determine the incidence, histomorphological features, and immunohistochemical features of papillary adenoma and elucidate its potential relationship to RCC. We reviewed 542 consecutive nephrectomy specimens over an 8-year period. Immunohistochemistry was carried out with antibodies specific for alpha-methyl-coenzyme A racemase (AMACR) and glutathione S-transferase alpha (clear-cell RCC marker). Thirty-eight (7%) nephrectomy specimens showed histologic evidence of papillary adenoma. Of these 38 cases, 18 (47%) arose in the setting of papillary RCC (PRCC). Seven papillary adenomas (18%) occurred in the setting of acquired polycystic kidney disease (APKD), 6 in clear-cell RCCs, 3 in chromophobe RCCs, 2 in end-stage kidney disease, 1 in oncocytoma, 1 in angiomyolipoma, and 1 in renal schwannoma. Furthermore, papillary adenomas were more commonly found in kidneys removed for PRCC (25%, 18/71) than in kidneys harboring clear-cell RCC (1.9%, 6/318). Histomorphologically, papillary adenomas were characterized by varying proportions of papillae and tubules formed by cuboidal cells with scant basophilic cytoplasm similar to those in type 1 PRCC. Adenomas associated with PRCC tend to be multiple in number (61% [11/18] of cases had >2 adenomas; mean, 5). In contrast, 100% of papillary adenomas arising in other conditions had less than 2 adenomas. Most of the adenomas (82%, 31/38) stained strongly for AMACR in a fashion similar to that of PRCC. The 7 AMACR-negative cases all arose in the setting of APKD. In this study of surgical specimens, the high coincidence, multifocality, and histologic and immunohistochemical similarities between papillary adenoma and PRCC suggest that the 2 are strongly associated and may represent a continuum of 1 biologic process. In contrast, adenomas associated with APKD exhibit distinct morphological and immunohistochemical features and, therefore, may have an entirely different pathogenesis.

MR urography in children

MR urography represents the next step in the evolution of uroradiology in children by combining superb anatomic imaging with quantitative functional evaluation in a single examination that does not use ionizing radiation. MR imaging has inherently greater soft-tissue contrast than other imaging techniques. When used in conjunction with dynamic scanning after administration of a contrast agent, it provides non-invasive analysis of the perfusion, concentration and excretion of each kidney. The purpose of this review is to outline our experience with more than 500 MR urograms in children. We outline our technique in detail, showing how we calculate differential renal function and how we assess concentration and excretion in the different regions of the kidney. We show that the dynamic contrast-enhanced data can be processed to yield quantitative measures of individual kidney GFR. In the clinical section we show how MR urography adds unique aspects to the anatomic evaluation of the urinary tract, and by combining the anatomic information with functional information, how we assess hydronephrosis and obstructive uropathy, congenital malformations, pyelonephritis and renal scarring.

Spectrum of pediatric developmental and genetic renal lesions and associated congenital malformations--an autopsy study from north India

Pediatric developmental and genetic renal lesions are a known cause of mortality in the perinatal/neonatal period. These lesions are associated with a wide range of extrarenal congenital malformations that influence the outcome of the patients. In this autopsy study, we have analyzed the spectrum of pediatric developmental and genetic renal lesions and their associated congenital malformations. A total of 4,099 autopsies (20 weeks of gestation to 1 year of life) were reviewed, of which 158 cases (3.85%) of pediatric developmental (143 cases) and genetic renal lesions (15 cases) were found. Autosomal recessive polycystic kidney disease was the commonest genetic lesion. Primitive ducts with cuffing of immature mesenchyme--the sine qua non of renal dysplasia--was found in all cases of dysplasia. Associated congenital malformations were seen in all cases and thus a thorough search for them is mandatory. Ductal plate malformation was found in all cases of autosomal recessive polycystic kidney disease and in 1 case of bilateral multicystic dysplasia.

Renal cystic diseases: a review

This review aims to assist in the categorization of inherited, developmental, and acquired cystic disease of the kidney as well as to provide a pertinent, up-to-date bibliography. The conditions included are autosomal-dominant polycystic kidney disease, autosomal-recessive polycystic kidney disease, unilateral renal cystic disease (localized cystic disease), renal simple cysts, multicystic dysplastic kidney, pluricystic kidney of the multiple malformation syndromes, juvenile nephronophthisis and medullary cystic disease, medullary sponge kidney, primary glomerulocystic kidney disease, and glomerulocystic kidney associated with several systemic disorders mainly of genetic or chromosomal etiology, cystic kidney in tuberous sclerosis, and in von Hippel-Lindau syndrome, cystic nephroma, cystic variant of congenital mesoblastic nephroma, mixed epithelial stromal tumor of the kidney, renal lymphangioma, pyelocalyceal cyst, peripylic cyst and perinephric pseudocyst, acquired renal cystic disease of long-term dialysis, and cystic renal cell carcinoma and sarcoma. Whereas the gross and histologic appearance of some of these conditions may be diagnostic, clinical and sometimes molecular studies may be necessary to define other types.

Concomitant anomalies in 100 children with unilateral multicystic kidney

OBJECTIVES

To determine the incidence and type of associated urogenital anomalies in children with a unilateral multicystic kidney and to assess in children with nephrectomy the additional diagnostic value of cystoscopy and, in girls, of colposcopy.

METHODS

This was a follow-up study of 100 fetuses with antenatally detected unilateral multicystic kidneys. After ultrasound confirmation of the diagnosis within a few days after birth voiding cystourethrography and isotope scan were performed in 83 of the surviving children to exclude vesicoureteral reflux and to establish renal function. Eighty-one children underwent nephrectomy and, prior to surgery, all underwent cystoscopy and girls also underwent colposcopy.

RESULTS

Seventy-five children had one or more additional urogenital anomalies: 39 had anomalies of the contralateral kidney, 40 had anomalies of the ipsilateral kidney and 30 had one or more anomalies of the lower urogenital tract. With cystoscopy 54 anomalies of the genitourinary tract were detected in 48 children and with colposcopy three anomalies were detected in 35 girls. Eighty-one children had a nephrectomy or heminephrectomy and 33 of them needed other urological intervention. Thirteen fetuses died (mostly from agenesis of the contralateral kidney) and six infants had no surgery at all.

CONCLUSION

Children with a unilateral multicystic kidney are at considerable risk of having other urogenital anomalies. When cystoscopy and colposcopy are added to routine investigations the rate of detection of anomalies is 75%, twice that reported in the literature.

Expression of laminin and fibronectin in renal dysplasia

The pathogenesis of renal dysplasia is a matter of debate. Recent theories have conceptualized the role of extracellular matrix proteins in the genesis of renal dysplasia. During normal nephrogenesis, collagen type I and III and fibronectins are lost and laminin and syndecan appear once proper induction has occurred. Any deviation from the normal pattern is said to lead to dysplasia. In this study, the expressions of adhesive glycoproteins, laminin, and fibronectin were studied immunohistochemically in 25 autopsy cases of renal dysplasia and normal age-matched control cases. These cases of renal dysplasia were categorized into 3 groups based on the period of gestation: 20 to 26 weeks, 27 to 33 weeks, and 34 to 40 weeks. The immunohistochemical findings were graded from 0 to 4+ based on the visual intensity. Chi-square analysis was used to calculate the difference in expressions of laminin and fibronectin in cases and controls as a whole and within and between age groups. Immunostaining for laminin in all age groups showed a significant difference in expression between dysplastic kidneys (less expression) and normal controls (greater expression). In the case of fibronectin expression, all but 1 group showed a significant difference, with dysplastic kidneys showing more and normal controls showing less expression. The inference derived is that laminin expression decreases and fibronectin expression increases in renal dysplasia compared with normal nephrogenesis.

Cystic kidney disease presenting in infancy

AIM

The clinical, histological and imaging findings of 12 children with ultrasound features of severe renal cystic disease presenting in the first year of life were reviewed.

METHODS AND RESULTS

Two children had cystic dysplasia and four had autosomal dominant polycystic disease. Two had a malformation syndrome, one a variant of Meckel syndrome and the other Bardet Biedl syndrome. One had autosomal recessive polycystic disease and in three there was no final diagnosis. Intravenous urography gave non-specific information. In six cases clinical findings combined with imaging established a diagnosis. Diagnosis was established by biopsy in two and gave supportive evidence in one. Outlook for renal function is variable. One child has had a transplant and one is on dialysis awaiting a transplant. Three have a degree of renal failure and one has died. Six have normal renal function. Renal cystic disease is the common pathway for a heterogeneous group of disorders as shown in these children.

CONCLUSION

It is emphasized that a specific diagnosis could not be made from the renal sonographic appearances alone, nor could any prognostic implications for renal function be made. Contrast retention on intravenous urography was also insufficiently specific to be of value. Ultrasound of the parents was the most useful imaging procedure and should be done in all cases.

Involution rate of multicystic renal dysplasia

OBJECTIVE

To document the involution rate and long-term results of management of multicystic dysplastic kidney.

MATERIALS AND METHODS

Data were collected retrospectively for all 23 infants (16 boys) with multicystic dysplastic kidney who were treated at our center over the last 19 years (1977-1995). The diagnosis was based on prenatal ultrasound in 18 patients and on palpable abdominal mass in 5, and confirmed in all patients by postnatal ultrasound and radioisotope scan. Voiding cystography was performed in 18 patients to exclude vesicoureteral reflux. Mean follow-up was 46 months (range, 3 months to 5 years) and included serum creatinine measurements and renal ultrasonography.

RESULTS

Two groups of patients were identified. Ten (43.6%) with other urologic abnormalities (group A) and 13 patients without other urologic abnormalities (group B). Vesicoureteral reflux was observed in 4 patients. Nephrectomy was performed in 4 patients, all from group B. The other 19 patients were treated conservatively. Complete involution was observed in 8 patients in group A and 6 in group B after a mean follow-up period of 9.2 and 10 months, respectively. Two patients, 1 from each group, later underwent nephrectomy not because of no involution but because of an increase in the size of the kidney involved.

CONCLUSION

Patients with multicystic renal dysplasia have significant associated urologic malformations, and the natural history of the disease is unpredictable. All patients require appropriate investigation of the urinary tract and long-term follow-up. The most outstanding finding of the study is the much higher involution rate of multicystic renal dysplasia and the rate of associated urologic abnormalities than that reported in the literature. Surgery remains an option for the patients in the absence of no involution. multicystic dysplastic kidney, surgery, conservative.

Multicystic renal dysplasia diagnosed in the antenatal period: a note of caution

OBJECTIVE

To document the urological problems associated with multicystic renal dysplasia (MCRD), to assess the efficacy of radiological methods for following the natural history of MCRD and to review current experience in the light of historical data regarding this condition.

PATIENTS AND METHODS

From January 1982 to December 1992 data were obtained prospectively on 62 patients (41 boys and 21 girls, age range 1-11 years) who had a diagnosis of MCRD suspected on antenatal ultrasonography. All patients had the diagnosis confirmed with radioisotope scans and micturating cystograms. Serum creatinine was measured in each patient and repeated clinically as indicated. Follow-up was from 1 to 11 years, with a clinical review and an annual ultrasonogram. The natural history of these patients was compared with those in other published studies.

RESULTS

Of the 62 patients, 12 had associated vesicoureteric reflux. Four patients developed impaired renal function during the course of observation and 10 patients required urological surgery for other pathologies. In the patients managed conservatively, 38% underwent no resolution on sequential ultrasonograms during the 2-year follow-up, and in four children, where complete resolution of the MCRD had occurred on ultrasonography, significant cellular renal masses were excised at subsequent surgery.

CONCLUSION

Patients with MCRD have significant associated urological malformations and the natural history in such patients is unpredictable. We do not regard MCRD as an entirely benign condition and feel that all patients require appropriate investigation of their urinary tract and long-term follow-up where conservative treatment is instituted. From the natural history of these patients, reviewed in conjunction with the literature, we recommend that decisions for management can only be taken with the full informed consent of the parents and that surgical excision is offered as part of that process.

Renal cell carcinoma arising in a regressed multicystic dysplastic kidney

Controversy surrounds the management of multicystic dysplastic kidney. Recent advances in radiological imaging have resulted in a higher incidence of its detection, and they provide an accurate noninvasive means of diagnosis and followup. Consequently, the need for surgical removal of these lesions is being reevaluated. We report a case of renal cell carcinoma arising from solid renal dysplasia associated with a regressed multicystic dysplastic kidney. We emphasize the potential risk of nonoperative management of these lesions and further define the spectrum of malignant degeneration associated with renal dysplasia.

An unusual cystic lesion histologically similar to autosomal dominant polycystic kidney disease in a child with aniridia and del 11p13

The association of Wilms tumor with an interstitial deletion on the short arm of chromosome 11 is well established. Specifically, the 11p13 band has been implicated in the syndrome of Wilms tumor, aniridia, genitourinary abnormalities and mental retardation. Only rarely have other renal lesions been associated with the chromosomal abnormality del 11p13. We report a case of a segmental cystic lesion, histologically akin to autosomal dominant polycystic kidney disease, in a child with aniridia and the del (11)(p12p14) karyotype.

Renal cystic disease in infants and children

Renal cystic disease is a common abnormality of the kidney in the pediatric age group. Cystic disease may occur as a sporadic dysplasia or, somewhat more commonly, represent a genetic disorder. Establishment of an accurate diagnosis, prognosis, and treatment requires a broad approach to the problem, including radiologic imaging, renal function testing, and occasionally surgical biopsy. Interpretation of the imaging studies requires understanding of the patterns of renal cystic disease in the pediatric age group.

Unilateral renal cystic disease: a case presentation

An infant who presented with a unilateral renal cystic process underwent nephrectomy due to hypertension. There was no evidence of any other disease process. Family history and investigation were negative for renal cystic disease or other genetic disease process. The pathology most resembled autosomal dominant polycystic kidney disease or a specific entity described as unilateral renal cystic disease.

A Case of Cystic Nephroma

The authors describe an uncommon case of cystic nephroma. They define the histologic characteristics which lead to correct diagnosis, while showing how difficult preoperative diagnosis is (ultrasound, CT, angiography). They discuss treatment and affirm that nephrectomy is still the choice operation in relation to the potential malignity of the lesion.

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%.

Autosomal dominant polycystic kidney disease in infants: asymmetric disease mimicking a unilateral renal mass

Unilateral radiographic presentation of autosomal dominant polycystic kidney disease is detected only rarely in infants and may suggest the presence of a complex cystic mass. We report such a case and review the literature concerning unilateral presentation of autosomal dominant polycystic kidney disease in infants and children.