Ultrasound Features of Ossifying Renal Tumor of Infancy: A Report of Four Cases

Ossifying renal tumor of infancy (ORTI) is an extremely rare benign renal tumor that typically presents with painless gross hematuria in infants. We describe the ultrasound features of four pathologically confirmed cases. All lesions were well-defined, hyperechoic masses located near a renal pole, protruding into the collecting system while preserving the renal contour. Calcification with posterior acoustic shadowing was present in every case. In the two cases with stored color Doppler images, internal signals were sparse. Recognition of this sonographic pattern may raise suspicion for ORTI and contribute to the preoperative differential diagnosis.