Renal dysplasia masquerading as a renal mass in a child on hemodialysis

Pathological renal mass is uncommon in children. It is important to differentiate this from a benign mass or mass-like lesion (pseudomass) for proper management. Renal dysplasia is a common finding in patients with end stage renal disease and can mimic a renal mass. Here, we report a 16-year-old girl on hemodialysis who was found to have a nodular right renal mass in the sonogram. Magnetic resonance imaging confirmed the nodular mass. She underwent right nephrectomy and the histopathology revealed features of renal dysplasia and end stage kidney disease without any evidence of malignancy. No further treatments were necessary. This case demonstrates that a nodular renal mass in dialysis patients does not always mean malignancy and could be a pseudomass from severe renal dysplasia. Since a sonogram may not be able to clearly define the etiology of solid mass in these patients, further evaluations including a renal histology and/or other imaging modalities are often necessary.