Toxocariasis mimicking liver, lung, and spinal cord metastases from retinoblastoma.

A boy with bilateral retinoblastoma underwent metastatic surveillance for increased risk of systemic and central nervous system metastasis because of the extensive choroid and optic nerve invasion in his enucleated eye. Two years after finishing chemotherapy, surveillance MRI showed multiple new liver, lung and spinal cord lesions. High Toxocara antibody titers, eosinophilia, and elevated IgE levels supported a diagnosis of toxocariasis, rather than retinoblastoma metastasis. This is the first report of early, asymptomatic spinal cord toxocariasis diagnosed incidentally through metastatic surveillance.