Middle cerebral artery occlusion due to paradoxical embolism diagnosed by pulmonary artery thrombosis in the absence of deep vein thrombosis: A case report.

A definitive diagnosis of paradoxical embolism generally requires confirmation of an arterial embolic event, a right-to-left shunt, identification of a venous thrombus, and exclusion of other embolic sources. In clinical practice, pulmonary embolism may be identified even in the absence of detectable deep vein thrombosis. In the present case, paradoxical embolism was considered highly probable based on the identification of a pulmonary artery thrombus despite the absence of deep vein thrombosis. A 54-year-old woman underwent successful thrombectomy with subsequent neurological improvement. Repeated postoperative ultrasonography showed no evidence of deep vein thrombosis. Transesophageal echocardiography revealed a patent foramen ovale, and contrast-enhanced computed tomography identified a pulmonary artery thrombus in the absence of deep vein thrombosis. Anticoagulation therapy resulted in complete thrombus resolution without recurrence.