Acute Pulmonary Thromboembolism in a Patient with Nutcracker Syndrome and Antiphospholipid Syndrome.

Nutcracker syndrome (NCS), which is defined as compression of the left renal vein between the aorta and the superior mesenteric artery, is usually benign and self-limiting. Long-term renal venous retention increases the risk of renal vein thrombosis. However, NCS rarely develops into isolated thrombosis of the left renal vein; the reason for this process remains unknown. We describe a young man with antiphospholipid syndrome, who developed overt pulmonary thromboembolism due to an isolated thrombus in the left renal vein. Complicating antiphospholipid syndrome might trigger acute pulmonary thromboembolism (APTE) in patients with NCS. To the best of our knowledge, this is the first report of APTE arising due to isolated left renal vein thrombosis in patients with NCS.