Abstract
Wilms tumor (nephroblastoma) is the most common renal malignancy of childhood and typically presents as a painless abdominal mass. The high success rates of surgery and chemotherapy make recurrence of Wilms tumor uncommon. We report the case of a 5-year-old girl who underwent radical nephrectomy and chemotherapy for a Wilms tumor, but suffered a relapse of the tumor to the lung. The metastasis was initially detected as a density on chest radiograph that was, coincidentally, in the same location as a recently explanted chest port. The diagnosis of recurrent malignancy was thus obscured by the patient's history as well as a correlating physical examination finding of a palpable mass at the site of the previously placed chest port. Moreover, the mass was not seen on lateral view, all of which suggested an alternative diagnosis of granulation tissue versus seroma rather than recurrent Wilms tumor. A high degree of clinical suspicion was necessary on the part of the clinician and radiologist to diagnose the relapse.