EARLY DETECTION OF SMALL NEPHROBLASTOMAS BY HIGH-RESOLUTION SONOGRAPHY IN CHILDREN

Introduction: Current publications focus on the sonographic features o f large nephroblastomas. Since high resolution ultrasound transducers are available, detection of small nephroblastomas became possible. The aim of the study was the definition of sonographic features of small renal tumors in children. Methods: Nephroblastomas with maximum diamet er of 4 cm or less were studied. 9 patients with 12 renal tumors were investigated. Results of high-resolution ultrasound were compared to i ntraoperative findings and to the results of computed tomography and m agnetic resonance. Results: Characteristic features of small nephrobla stomas are discreet hyperechogenity, clear demarcation from renal pare nchyma and disruption of the renal shape. The results of ultrasound ex amination were confirmed during operation for 8 of 12 renal tumors. Tw o nephrogenic rests and 2 small nephroblastomas localized near the ren al capsule were missed by sonography, 1 of these lesions was also miss ed by NMR. Conclusion: Ultrasound can detect even very small nephrobla stomas. Superficial subcapsular lesions may not be detected by ultraso und nor MRT. To detect small nephroblastomas and nephrogenic rests the combination of imaging methods still remains useful.