Young patient with acute ischemic stroke due to papillary carcinoma of the thyroid

Hypercoagulability is a condition predisposing to arterial or venous thrombosis and is associated frequently with malignancy. We present a rare acute ischemic stroke in a young patient that was the presenting feature for a newly diagnosed papillary carcinoma of the thyroid. Extensive vascular and hematological work-up was normal except for a large patent foramen ovale (PFO). This finding, along with the association of most vascular events with hypercoagulability being of venous origin, makes the mechanism of paradoxical embolism through the large PFO the probable cause of stroke in our patient.