Type 1 primary hyperoxaluria in pediatric patients: renal sonographic patterns.

Objective: Our aim was to review the sonographic features of type I primary hyperoxaluria in children and to correlate the sonographic patterns with the clinical development of end-stage renal disease (ESRD).

Materials And Methods: We performed a retrospective analysis of the clinical and imaging files of 13 patients with type I primary hyperoxaluria who were treated in one institution and of the sonographic patterns and the clinical follow-up reports.

Results: We encountered the following two sonographic patterns: medullary nephrocalcinosis in eight patients and cortical nephrocalcinosis in five patients. The sonographic appearance of cortical nephrocalcinosis is quite specific: a hyperechoic peripheral renal cortex with acoustic shadowing behind it. Medullary nephrocalcinosis is less specific because there are many other causes of hyperechoic pyramids. All patients with medullary nephrocalcinosis developed lithiasis during the course of the disease. All patients with cortical nephrocalcinosis but only two of eight with medullary nephrocalcinosis developed ESRD.

Conclusion: Sonography can be used differentiate the two patterns of type 1 primary hyperoxaluria. The cortical nephrocalcinosis type carries a higher risk of developing ESRD.