Medullary sponge kidneys and unilateral Wilms tumour in a child with Beckwith-Wiedemann syndrome

The effectiveness of Wilms tumor screening in Beckwith-Wiedemann spectrum

PURPOSE

It is well documented that patients with Beckwith-Wiedemann spectrum (BWS) have a significantly higher risk of developing Wilms tumor (WT) than the general population. There has been little research on the timing of WT diagnosis in BWS in regard to optimizing suggested screening protocols.

METHODS

A literature search was performed to identify all reports of patients with BWS and WT. These data were combined with unpublished data from patients in the authors' cohorts. Age at WT diagnosis was compared against data collected through the NIH Surveillance, Epidemiology, and End Results Program (SEER) registry.

RESULTS

Patients with BWS had a significantly higher incidence of WT diagnoses between age 12 and 84 months compared to patients in the SEER registry. Patients with BWS and WT diagnosed through screening had significantly lower stages at diagnosis compared to patients with BWS that were not screened.

CONCLUSIONS

Screening until age 7 years is effective in detecting close to 95% of all WT in patients with BWS.

Hematuria in the newborn

Microscopic and gross hematuria, while rare in healthy newborns, is more common in premature infants, particularly those cared for in the neonatal intensive care unit. Hematuria may be transient, but may require evaluation, investigation, and intervention in a timely manner. This article discusses the causes, workup, and treatment of the more common forms of newborn hematuria.

Medullary sponge kidney: causes and treatments

Medullary sponge kidney is a little known and little understood disease. A patient with a medullary sponge kidney may undergo decades of suffering in the form of infections and pain before any diagnosis is even made. When a diagnosis is made, it is more than likely to be an incidental finding from a test for another problem. However, on diagnosis there are a number of options available to treat this condition. These include non-invasive treatments such as drug therapy, diet or extracorporeal shock wave lithotripsy, to invasive therapies such as percutaneous nephrolithotomy, ureteroscopy and more advanced surgery. The aim of this article is to highlight this little known condition, outline the effects, and discuss the treatment options available to patients.

Rabson-Mendenhall syndrome: medullary sponge kidney, a new component

Rabson-Mendenhall syndrome is a rare genetic disorder characterized by severe insulin resistance, extreme hyperinsulinemia, postprandial hyperglycemia, growth retardation, and dysmorphisms. Enlargement of the kidneys and nephrocalcinosis have been described previously. We report a 10-year-old boy who presented with gross hematuria, unilateral hydronephrosis, and the initial diagnosis of bilateral extensive medullary nephrocalcinosis. Medullary sponge kidney (MSK) was included in the differential diagnosis given the ultrasound findings. Further evaluation by intravenous pyelogram confirmed the suspected bilateral MSK. Given the patient's history of hydronephrosis due to an obstructing renal stone and MSK, urine calcium excretion was assessed and found to be markedly increased at 9.5 mg/kg per day. To our knowledge, this is the first report of Rabson-Mendenhall syndrome and an association with MSK. We recommend evaluation for nephrocalcinosis, MSK, and hypercalciuria in all children diagnosed with Rabson-Mendenhall syndrome.

Risk of tumorigenesis in overgrowth syndromes: a comprehensive review

Overgrowth syndromes (OGS) comprise a heterogeneous group of disorders in which the main characteristic is that either weight, height, or head circumference is 2-3 standard deviations (SD) above the mean for sex and age. A striking feature of OGS is the risk of neoplasms. Here, the relative frequency of specific tumors in each OGS, topographic location, and age of appearance is determined by reviewing published cases. In some OGS (Perlman, Beckwith-Wiedemann, and Simpson-Golabi-Behmel syndromes and hemihyperplasia) more than 94% of tumors appeared in the abdomen usually before 10 years of age, mainly embryonal in type. In Perlman syndrome, only Wilms tumor has been recorded, whereas in Sotos syndrome, lympho-hematologic tumors are most frequent. Based on literature review, a specific schedule protocol for tumor screening is suggested for each OGS. A schedule with different intervals and specific tests is proposed for a more rational cost/benefit program for these disorders.

An unusual association of contralateral congenital small kidney, reduced renal function and hyperparathyroidism in sponge kidney patients: on the track of the molecular basis

Of unknown pathogenesis, sponge kidney (SK) is variably associated with nephrocalcinosis, stones, nephronic tubule dysfunctions and precalyceal duct cysts. Amongst 72 unrelated renal SK patients with renal stone disease, we detected one with unilateral bifid renal pelvis and six with unilateral small kidneys (longitudinal diameter difference >15%). Secondary causes of small kidney were excluded. Of the seven cases, four had reduced renal function (67 vs 7% in the entire cohort), and three developed hyperparathyroidism during follow-up (43 vs 4%). The pathogenesis of SK ought to explain why anatomical structures of different embryological origin are involved (the precalyceal and collecting ducts and the nephron) and why there is frequent association with hyperparathyroidism. In embryogenesis, the metanephric blastema synthesizes the chemotactic glial-derived neurotrophic factor (GDNF) to prompt the ureteric bud to branch off from Wolff's mesonephric duct, and to approach and invade the blastema. The bud's tip expresses the GDNF receptor (RET). RET-GDNF binding is crucial not only for the correct formation of ureters and collecting ducts (both of Wolffian origin), but also for nephrogenesis. We advance the hypothesis that SK results from a disruption in the ureteric bud-metanephric blastema interface, possibly due to one or more mutations or polymorphisms of RET or GDNF genes. This would explain: the concurrent alterations in precalyceal ducts and the functional defects in the nephron, the occasional association with size and the functional asymmetry between the two kidneys, some degree of renal dysplasia causing the reduction in the glomerular filtration rate and (given the role of RET in parathyroid cell proliferation) the association with hyperparathyroidism.

Medullary sponge kidney

Medullary sponge kidney is a benign asymptomatic developmental anomaly of the kidney mostly seen in adult females. Presentation in childhood is uncommon. Urinary tract infection, nephrolithiasis, hematuria and hypercalciuria are the common complications. We report a eleven-year-old female child who presented with recurrent urinary tract infection and nephrolithiasis and was found to have bilateral medullary sponge kidney.

Current concepts and controversies in imaging of renal cystic diseases

Renal cystic disease compromises a diverse group of inherited and acquired entities. This article reviews the clinical, pathologic, and radiologic findings of eight renal cystic diseases. For each entity, the current concepts of pathogenesis and pathophysiology are discussed. When appropriate, controversies concerning terminology, management, and malignant potentials are addressed. Renal cystic diseases that are discussed include autosomal dominant and autosomal recessive polycystic kidney disease, medullary sponge kidney, medullary cystic disease, multicystic, dysplastic kidney, von Hippel-Lindau disease, acquired cystic kidney disease, and tuberous sclerosis.

Nephroblastoma and end-stage renal failure with bilateral cystic kidneys

A child of 10 years 5 months presenting with chronic renal failure had bilateral cystic kidneys. Biopsy of a right lower-pole solid mass revealed nephroblastoma. At bilateral nephrectomy, both kidneys were both replaced by variable-sized cysts with a unifocal nephroblastoma on the right. Renal failure with nephroblastoma is uncommon and is usually either a manifestation of the Drash syndrome or a complication of chemotherapy. The need to assess both kidneys in a child with any other renal abnormality in addition to a renal mass should always be considered.

A virilized patient with congenital hemihypertrophy

An 18 year old woman with congenital hemihypertrophy of her left side, presented with the rapid onset of virilism, hypertension and a cushingoid appearance. A computed tomographic examination revealed adrenal and hepatic masses. Adrenocortical carcinoma was confirmed by surgical pathology. Hemihypertrophy is linked to a variety of benign and malignant disorders that usually appear during childhood. These disorders include adrenocortical carcinoma and hepatoblastoma. We bring this case to clinical attention to increase awareness that adult patients with congenital hemihypertrophy are still at a significant risk of developing neoplasms.