Renal Tumor and Trauma: a Pitfall for Conversative Management

Purpose: Conservative management has been largely used for renal trauma. Although this approach is safe and highly recommended, it can hide a pre-existing unknown condition, such as tumors or urinary malformations. A high index of suspicion is needed for early recognition of these conditions. We present four cases treated at the Pediatric Oncology Institute - Federal University of Sao Paulo, which have been initially treated conservatively for renal trauma. Materials and Methods: We reviewed all 218 renal cases of renal tumors treated at our institution in a 22-year period, searching for associated trauma events. Results: Four cases of renal tumors were initially treated conservatively for blunt renal trauma of low energy mechanism. Patients' ages ranged from 7 to 12 years old. Two patients had no previous symptoms, one patient had hematuria and another had an abdominal mass. Computerized Axial Tomography (CT) of the abdomen revealed disparate magnitude of the renal bleeding to the low energy mechanism of trauma. All patients underwent surgical treatment. Kidney specimens showed Wilms tumor in three cases and renal carcinoma in one. Conclusions: The association between renal tumors and trauma should be suspected when renal trauma hemorrhage on abdominal CT scan does not match the low energy mechanism of blunt abdominal trauma. The key for a successful diagnosis of renal tumor or congenital malformations is the high index of suspicion for these conditions.