Botryoid Wilms' Tumor in a Child Presenting with Gross Hematuria: A Case Report

We report a unique case of botryoid Wilms' tumor with its characteristic imaging findings in a 5-month-old boy presenting with gross hematuria. In our case, ultrasonography revealed lobulated hyperechoic lesions filling the pelvicalyceal system without parenchymal invasion, mimicking a blood clot. However, magnetic resonance imaging (MRI) demonstrated the exact extent of the lesion with diffusion restriction and delayed enhancement suggestive of a tumor. Despite their rarity, botryoid Wilms' tumors should be included in the differential diagnosis of lobulated renal pelvic lesions presenting as gross hematuria in children, and MRI can suggest the diagnosis.