Cholesterol crystal embolization caused by anticoagulant therapy

CaseA 72-year-old white man, with a history of type II diabetesmellitus,hypertension,chronicrenalinsufficiency,andatrialfibrillation, had been receiving warfarin, 5 mg daily, for1 year when he developed macroscopic hematuria. He wasadmitted to our hospital with an International NormalizedRatio(INR)of14,causedbyincorrectuseofthemedication.Onthethirddayofadmission,hehadnofurther evidence ofhematuria and the prothrombin time was normal aftervitamin K administration. On the fourth day, however, hesuddenlydevelopedblue-coloredtoesandacutedeteriorationof renal function. Physical examination revealed discretelivedo reticularis on both feet, tender, blue-colored second,third,fourth,andfifthrightandlefttoes,withgoodperipheralpulses (Fig. 1). Laboratory examinations revealed an elevationof serum urea nitrogen at 239 mg/dL (3 days before, 192 mg/dL; normal, 10–50 mg/dL) and creatinine at 6.05 mg/dL(3 days before, 4.66 mg/dL; normal, 0.7–1.3 mg/dL). Thewhite blood cell count was 10.5 · 10