We report the case of a patient in whom brain MR imaging was requested for initial symptoms of intracranial hypertension. The presence of multiple intracranial hemorrhagic lesions suggested brain metastases. Body screening showed periosteal osteosarcoma of the left fibula with no lung metastases, but with a patent foramen ovale which probably allowed neoplastic cells to reach the brain without being filtered through the lungs. The conclusion of this study was that a left-right cardiac communication is to be considered in cases of isolated brain metastases from osteosarcoma.