Stroke caused by a myxoma stenosing the common carotid artery

We report a case of stroke due to stenosis caused by a myxoma in the common carotid artery with no evidence of a cardiac origin. Only 1 such case has been reported previously in the literature.

A previously healthy 37-year-old woman presented with repeated episodes of acute focal deficits together with motor, sensory, and language symptoms typical of left internal carotid territory involvement. Brain magnetic resonance imaging showed acute and subacute ischemic lesions in the territory of the left middle cerebral artery and border zone infarcts (middle cerebral artery with anterior and posterior cerebral arteries). Magnetic resonance angiography showed a filling defect in the distal portion of the left common carotid artery causing stenosis over 70%. Transesophageal echocardiography showed no embolic sources. Blood tests ruled out a prothrombotic state.

The image was initially interpreted as a possible subacute thrombus and anticoagulation was started. No changes were observed in the follow-up carotid ultrasound examination after 12 days of treatment. A gelatinous mass was removed during carotid surgery. No subjacent lesion was observed in the vessel wall. Pathology examination showed a spindle cell fibromyxoid tissue with fibrinoid material typical of myxoma.

We hypothesize that the myxoma originated in the vessel, or alternatively, that a cardiac myxoma embolized without leaving a residual cardiac tumor. Although exceptional, myxoma should be added to the list of unusual causes of carotid artery stenosis causing stroke.