Ultrasonographic Features of the Kidney in Patients With Frasier Syndrome and Stage 5 Chronic Kidney Disease: A Case Report and Literature Review

BACKGROUND: Frasier syndrome (FS) is a rare WT1-related disorder characterized by progressive nephropathy and diffuse renal parenchymal damage on imaging. Ultrasonographic findings of end-stage kidney disease in FS have rarely been documented. METHODS: We present the case of a 12-year-old boy who was diagnosed with FS, harbored a heterozygous c.1447+5G>A mutation in his WT1 gene, and developed CKD Stage 5. Renal ultrasonography and non-contrast CT were performed. A systematic literature review was conducted to contextualize the imaging findings. RESULTS: Non-contrast CT revealed multiple areas of abnormal density in both kidneys, which raised suspicion of Wilms tumor. Ultrasonography demonstrated multiple avascular, non-encapsulated nodular hyperechoic areas on a background of diffusely abnormal parenchyma and ruled out malignant tumors. The literature review confirmed that similar findings have rarely been reported in FS patients with CKD Stage 5. CONCLUSION: These findings describe a distinctive end-stage renal ultrasound pattern in FS. Recognition of this pattern may help clinicians avoid unnecessary invasive procedures when renal malignancy is suspected in patients with advanced CKD.