An “accidental” discovery: Incidentally found metanephric adenofibroma in a 5-year-old male trauma patient

Metanephric adenofibroma is a rare pediatric renal tumor, which should be considered in cases of solid renal lesions that mimic Wilms tumor on both imaging and histology. We present a case of an incidentally found left renal lesion on a trauma computed tomography scan in a 5-year-old male patient. The patient underwent total nephrectomy, and the diagnosis of metanephric adenofibroma was made on histology. Radiologists should consider this entity in the differential for an incidentally found solitary renal mass in a pediatric patient. Prompting the pathologic diagnosis of this entity can spare patients from unnecessary chemotherapy and allow for nephron-sparing surgery.