Toxocariasis simulating hepatic recurrence in a patient with Wilms' tumor

We report the case of a 3-year-old girl with stage I Wilms' tumor of favorable histology. During the course of chemotherapy 5 months post-diagnosis, an abdominal ultrasonogram revealed hypoechoic areas consistent with hepatic tumor recurrence. A liver biopsy performed to rule out recurrence of the malignancy was suggestive of toxocariasis and the diagnosis was confirmed by serologic testing. Although the patient had few classic signs of visceral larva migrans, her eosinophilia and family social history should have suggested this possibility. This case demonstrates that hepatic toxocariasis should be considered in evaluating hepatic hypoechoic lesions in a child, even when features typical of the disease are absent.