Case Report: Pleural effusion in Wilms tumor - always malignant?

Wilms tumor (WT) is the most common renal malignancy seen in pediatric patients. Although lungs are the most common site of metastasis in Wilms tumor, non-malignant pleural effusion has been infrequently reported. Here, we report a case of an eleven-year-old female who presented with an abdominal mass and progressive breathlessness. On further evaluation, she was found to have a right-sided Wilms tumor with ipsilateral massive pleural effusion. The effusion resolved almost completely after four weeks of chemotherapy. We conclude that patients suffering from Wilms tumor presenting with pleural effusion need not be synonymous with metastatic disease and can have a favorable prognosis.