Venous thrombosis in blacks.

Case Presentation: A 42-year-old black woman is diagnosed with idiopathic (unprovoked) lowerextremity deep vein thrombosis (DVT) after presenting with leg swelling. She is treated with anticoagulation for 6 months without major complications and with stable international normalized ratios, and her lower-extremity symptoms completely resolve. She has sickle cell trait but no other chronic conditions. The patient’s mother also had an idiopathic DVT at 53 years of age. Physical examination is notable only for obesity (body mass index 33 kg/m) and absence of lower-extremity swelling, redness, and pain. D-dimer and follow-up lower-extremity Doppler ultrasound testing are negative. Testing for antiphospholipid antibodies was negative at the time the clot was diagnosed; further tests for thrombophilia have not been performed. She wants to know whether she should continue taking warfarin.