Acute pyelonephritis and subcapsular hematoma revealing a nephroblastoma

Nephroblastoma tumor is the most common renal tumor in children aged 1 to 5 years, typically presenting as an abdominal mass. However, other nonspecific signs may also reveal the disease. An unusual presentation, such as acute pyelonephritis or a subcapsular renal hematoma, is rarely an initial warning sign and should prompt investigation of an underlying cause, especially in the absence of trauma history. We report here a particular case of Wilms tumor, revealed by acute pyelonephritis and complicated by a subcapsular hematoma in a 6-year-old girl. We emphasize the importance of considering the diagnosis of Wilms tumor in any child presenting with renal hemorrhage, to improve prognosis and initiate therapeutic management as early as possible.