Significance of pleural effusion at diagnosis of Wilms tumor

Background. Pleural effusion is uncommon at diagnosis of Wilms tumor. Because the clinical significance of this finding has not been reported, a retrospective review of this entity was conducted. Procedure. The radiology reports and medical records of 233 patients with Wilms tumor who were treated at St. Jude Children's Research Hospital between 1985 and 2001 were reviewed. Results. Ten of the 233 patients (4.3%) had pleural effusions detected on pre-nephrectomy imaging studies. Computed tomography (CT) scans were more sensitive than chest X-rays in identifying pleural effusions. All of the patients with pleural effusions had tumors of favorable histology. Two patients had stage 11 disease, five had stage III disease, two had stage IV disease, and one had stage V (bilateral) disease. All of the effusions occurred on the same side as the primary kidney tumors and six effusions were associated with ascites. The two effusions that were tapped were negative for tumor cells. All 10 patients in our series were alive without recurrence with a median follow-up duration of 68 months, yet only two patients were treated with lung irradiation. Conclusion. Pleural effusion at presentation of Wilms tumor is uncommon and not associated with adverse prognosis. We recommend that pleural effusions be tapped whenever feasible if the results will change therapy. Patients with pleural effusions that are small and difficult to tap may be treated according to their local stage without pulmonary irradiation. Further analysis of pleural effusions in a larger group of patients is necessary to confirm our preliminary observations. (c) 2003 Wiley-Liss, Inc.