Pulmonary toxocariasis masquerading as metastatic tumor nodules in a child with osteosarcoma.

A 14-year-old male, who completed chemotherapy following limb salvage surgery for osteosarcoma approximately 2 years ago, was seen for routine follow-up. A CT scan revealed new scattered multifocal nodular lesions. An ultrasonography-guided percutaneous needle biopsy was done to confirm pulmonary metastasis of the underlying osteosarcoma. The lung biopsy showed findings of eosinophilic pneumonia with no evidence of malignancy. Peripheral eosinophilia was also noted. When a more thorough history revealed frequent intake of raw cow liver, we diagnosed pulmonary toxocariasis by ELISA for specific serum IgG antibody.