Simple renal cysts in children

Management of simple renal cyst in children: French multicenter experience of 36 cases and review of the literature

OBJECTIVE

The widespread use of renal ultrasonography has resulted in simple renal cysts (SRC) being discovered with increasing frequency in routine pediatric urological practice. Management of SRC, however, remains controversial. Most SRC are asymptomatic, are diagnosed incidentally, and have no clinical consequence. Our goal was to focus on management strategies for SRC in children with the support of our experience and a review of the literature.

MATERIALS AND METHODS

A literature review was made of SRC in children since 1950, analyzing epidemiologic data, diagnosis, and management. In addition, a retrospective multicenter study was conducted from 1998 to 2009. Patients included presented with a unique SRC. Data recorded were patient characteristics (age, gender), symptoms, imaging features of the cyst (size, side, pole, and location), type of management, and long-term outcomes. To focus on management, two groups of patients were defined: primary surgical management and primary conservative management consisting of clinical and US follow-up. Our results were compared with the literature.

RESULTS

Thirty-six cases were included. Fifteen patients were symptomatic. Comparing the two groups, long-term outcomes were similar. The only significant factors were preoperative (age of the patient, diameter and location of the cyst): the bigger the cyst, the more likely it was to be exorenal, and the greater the likelihood that surgery would be performed (p = 0.006). Symptoms were not a significant indicator for surgery.

CONCLUSION

According to the literature and our experience, and considering the benign natural history of SRC and the similar outcomes whatever the treatment, primary conservative management is recommended for all cases. Surgery should be restricted to symptomatic large compressive cysts, increase in cyst size on follow-up, and uncertain diagnosis. Percutaneous cyst aspiration with sclerotherapy has not yet been used enough to ascertain its safety, and requires prospective evaluation.

Transitional cell carcinoma arising in a calyceal cyst mimicking a cystic renal tumour

Solitary renal cysts are relatively common. The occurrence of transitional cell carcinoma (TCC) in a renal cyst is rare. We present the case of a 59-year-old man with a medical history of viral hepatitis B. During a workup for his hepatitis, a computed tomography scan revealed a large cystic tumour in the upper region of the left kidney. A radical left nephrectomy was performed. Microscopic examination of the cystic tumour revealed a grade 2 TCC. The cyst was lined by transitional epithelium. This is a case of a TCC growing within a renal calyceal cyst.

Urologic findings on computed tomography of the abdomen and pelvis in a pediatric population

OBJECTIVES

(1) Determine the number of urologic conditions diagnosed by computed tomography (CT) in children in the emergency department setting. (2) Identify which diagnoses were incidental. (3) Determine how often there was urologic follow-up by a local pediatric urologist.

PATIENTS AND METHODS

We reviewed the charts and radiologist interpretations of all CT scans of the abdomen and pelvis performed within 2 days of admission via our emergency department from July 2007 to June 2009. Patients were included if the diagnosis was new. If a urologic finding was noted on final read, the CT was re-examined by one of our urologists to verify the finding.

RESULTS

Among 2991 CT scans (one CT scan per patient), there were 213 (7%) new urologic findings: 124 were incidental; 144 patients (68% of patients with urologic findings) did not receive follow-up. Renal abnormalities were present in 127. The most common finding was renal cyst (69 patients). Ureteral abnormalities were present in 47. The most common ureteral finding was hydroureteronephrosis (40). Other anomalies identified included bladder (7) and scrotal (14) abnormalities, stones (13), and adrenal lesions (5).

CONCLUSION

Many urologic diagnoses are revealed during CT scans of the abdomen and pelvis. The majority are cysts, hydroureteronephrosis, and pyelonephritis. Many incidental findings have also been revealed in the emergency department setting.

Single-session percutaneous ethanol sclerotherapy in simple renal cysts in children: long-term follow-up

BACKGROUND

Simple renal cysts are rare in children and managed conservatively unless symptomatic.

OBJECTIVE

To demonstrate the efficacy and long-term results of single-session ethanol sclerotherapy in symptomatic simple renal cysts in children.

MATERIALS AND METHODS

Three simple renal cysts in three children (age 1, 5 and 16 years) were included in the study. Indications for treatment were flank pain (n = 1), hypertension (n = 1), and increasing cyst size and urinary tract infection (n = 1). The mean follow-up period was 5.5 years (range 3-7 years). The procedures were performed with the guidance of US and fluoroscopy and under IV sedation. After the cystogram, 95% ethanol with a volume of 40% of the cyst volume (but not more than 100 ml) was used as the sclerosing agent.

RESULTS

Two cysts disappeared completely, while the volume reduction was 99% for the third cyst at the end of the first year. CT demonstrated calcification of the cyst without an enhancing soft-tissue component in the third one 7 years after sclerotherapy. After the procedures, hypertension and pain resolved without any medication. There were no complications during the procedures or during follow-up. Cytological examination was unremarkable in all patients.

CONCLUSIONS

Percutaneous treatment of symptomatic simple renal cysts in children with single-session ethanol sclerotherapy is a safe, effective and minimally invasive procedure. Calcification owing to sclerotherapy can be observed on follow-up.

Polycystic liver and kidney diseases

There have been remarkable advances in research on polycystic liver and kidney diseases recently, covering cloning of new genes, refining disease classifications, and advances in understanding more about the molecular pathology of these diseases. Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary disease affecting kidneys. It affects 1/400 to 1/1000 live births and accounts for 5% of the end stage renal disease in the United States and Europe, and is caused by gene defects in the PKD1 or PKD2 genes. Compared to ADPKD, polycystic liver disease (PCLD) is a milder disease and does not lower life expectancy. Both diseases are usually adult-onset diseases. Defects in genes, which code the hepatocystin and SEC63 proteins, have just recently been found to cause PCLD. It now seems that ADPKD is caused by malfunction of the primary cilia, a cell organ sensing fluid movement, and that PCLD is a sequel from defects in protein processing. Autosomal recessive polycystic kidney disease (ARPKD) belongs to a group of congenital hepatorenal fibrocystic syndromes. All ARPKD patients have a gene defect in a gene called PKHD1, the protein product of which localizes to primary cilia. We summarize the present clinical and molecular knowledge of these diseases in this review.

Natural history of fetal simple renal cysts detected in early pregnancy

PURPOSE

In this 12-year prospective, longitudinal study we investigated the natural history of fetal simple renal cysts identified by ultrasonography in early pregnancy.

MATERIALS AND METHOD

A detailed sonographic examination of the fetus was performed between January 1987 and June 1998 in 29,984 consecutive pregnancies at 14 to 16 weeks of gestation. Amniocenteses and chromosomal investigations were done in all cases in which a simple renal cyst was detected in the fetus. Followup sonography was done in all cases of renal cyst during pregnancy, infancy and, when indicated, childhood.

RESULTS

Simple renal cysts were diagnosed at 14 to 16 weeks of gestation in 28 fetuses (1/1,100 pregnancies, 0.09%). In 25 fetuses the cysts resolved during pregnancy. In 2 fetuses the cysts remained benign but persisted postnatally and in 1 a renal cyst that was initially defined as simple was the first sign of unilateral multicystic dysplastic kidney. Except for nonseptated cystic hygroma in 1 fetus, none of the others had associated anomalies of the urinary or other organ systems and no chromosomal anomalies. Postnatal followup in all cases revealed healthy children.

CONCLUSIONS

A fetal simple renal cyst can be identified by ultrasonography in early pregnancy. In the absence of associated anatomical or chromosomal abnormalities, the majority of cysts will resolve during pregnancy without any sequelae. Given the transient nature of most fetal simple renal cysts detected in early pregnancy, it is possible that these cysts represent a distinct entity within the spectrum of cystic kidney diseases.

Caliceal diverticula developing into simple renal cyst

Although common in adults simple cortical renal cysts are rare in children. Caliceal diverticula are rare in adults and children. A case of a caliceal diverticulum apparently sealing off and becoming an isolated simple cyst in the renal parenchyma has been reported as an unusual complication of caliceal diverticula. There have been 2 other cases of caliceal diverticula becoming sealed off reported in the literature, although neither progressed to frank cysts. We report 2 cases of definite caliceal diverticula progressing to simple renal cortical cysts.

Unilateral presentation of adult-type polycystic kidney disease in children

Adult polycystic kidney disease is characterized by autosomal dominant inheritance, diffuse bilateral cystic kidney disease and onset during the young adult years. Relatively few cases of adult-type polycystic kidney disease in children have been reported. We describe a 4-year-old girl who appeared to have multiple, unilateral simple renal cysts by excretory urography and ultrasonography. There was no known familial renal cystic disease. When renal histology was consistent with adult-type polycystic kidney disease, screening nephrosonograms revealed that the mother also had the disease. We review 10 published cases of unilateral presentation of adult-type polycystic kidney disease in children. This report emphasizes the necessity of screening studies in parents of children with diffuse unilateral or bilateral cystic renal disease. Awareness of the unexpected unilateral presentation of adult-type polycystic kidney disease in children may allow a nonoperative diagnosis to be made.