Significance of pulmonary computed tomography at diagnosis in Wilms' tumor

Pulmonary lesions were found by computed tomography (CT) despite normal chest roentgenograms (CXR) at diagnosis in 11 of 124 patients with Wilms' tumor. All patients were entered on a treatment protocol at St Jude Children's Research Hospital from 1978 to 1986. The 11 patients all had favorable histology Wilms' tumor. Staging and therapy were based on interpretation of the CXR and abdominal findings. Excluding CT findings, one patient had stage I disease, two stage II, seven stage III, and one stage IV on the basis of multiple liver metastases. Four patients have relapsed: one with stage II and three with stage III. All relapses have been pulmonary. Overall, 4/11 (36%) relapsed. This relapse rate is considerably greater than the 20% overall relapse rate of patients treated according to this protocol though not statistically significant. These relapses suggest that such patients may be at increased risk for pulmonary recurrence. The results also indicate that small lesions initially noted only on CT scans of the chest in children with Wilms' tumor frequently represent metastatic tumor. Further studies of larger numbers of patients will be necessary to confirm these findings.