Acute renal vein thrombosis, oral contraceptive use, and hyperhomocysteinemia

Oral contraceptive use and hyperhomocysteinemia are considered to be relati vely weak risk factors for venous thromboembolism, We report a case of acut e renal vein thrombosis, a rare and aggressive form of thromboembolism, tha t occurred in a 21-year-old woman taking oral contraceptives, who was subse quently found to have marked hyperhomocysteinemia. This case suggests that the oral contraceptive and hyperhomocysteinemia may interact in a synergist ic manner in the pathogenesis of thrombosis. In oral contraceptive users wh o develop venous thrombosis in the absence of other risk factors, clinician s should consider investigations for an underlying prothrombotic biochemica l disorder.