Retrospective analysis of simple and stage II renal cysts: Pediatric nephrology point of view

Background: Increased ultrasonography (US) use has been correlated with an increased incidence of pediatric renal cysts. For simple and stage II cysts, the malignancy risk is low in adulthood, no follow up is recommended; but there is no consensus on childhood management. Given that pediatric renal cysts may be manifestations of hereditary cystic diseases, a different approach and follow up should be taken for these patients. Herein we present the clinical characteristics and follow-up data of pediatric patients with simple and stage II renal cysts.

Methods: This cross-sectional study involved 57 children (mean age, 12.44 ± 3.65 years) with simple (n = 35) and stage II cysts (n = 22) who were diagnosed and followed at the present institution for ≥2 years.

Results: The median follow-up period was 2.84 years for simple and 3.10 years for stage II cysts. None of the patients developed complications. No change in cyst diameter was detected in 65.7% of simple or in 45.5% of stage II cysts, whereas 13 simple cysts (37.1%) and eight stage II cysts (36.4%) increased in diameter. The diameter change per year was significantly higher in the stage II cysts than in the simple cysts (P = 0.017). Overall, 13 patients (22%) had an estimated glomerular filtration rate <90 mL/min/1.73 m² , and two patients had hypertension.

Conclusion: Although the malignancy risk of simple and stage II kidney cysts is low for this age group, potential complications such as renal dysfunction, hypertension and hereditary cystic disease should be closely monitored.