Visceral larval migrans masquerading as metastatic disease in a toddler with Wilms tumor.

A 22-month-old girl with a renal mass had multiple small pulmonary nodules on CT at her initial presentation. After biopsy and neoadjuvant chemotherapy, a Wilms tumor was resected and the pulmonary nodules were shown to have regressed on CT. Follow-up imaging 4 months after initial diagnosis demonstrated multiple new liver lesions and new pulmonary nodules with peripheral eosinophilia. Lung biopsy revealed granuloma formation with prominent eosinophils. The serum antibody titers for Toxocara canis were elevated. This case illustrates that toxocariasis should be considered as a rare differential diagnostic possibility for multiple liver lesions and multifocal peripheral pulmonary opacities in young children with Wilms tumor.