A 52-year-old man with type 2 diabetes mellitus and end-stage renal disease presented with painful and progressive cutaneous necrosis of his fingers, toes, and calves and generalized muscle weakness with difficulty getting out of bed and walking. He had undergone hemodialysis for the past year and had a brachiocephalic fistula in his left arm. Hismedical historywasalso significant forperipheral vascular disease, hypertension, andantiphospholipid antibody syndrome for which hewas receivingwarfarin sodium since 2010. His other medications were epoetin alpha, ferrous gluconate, cinacalcet hydrochloride, paricalcitol, sevelamer carbonate, amlodipine besylate, labetalol hydrochloride, lisinopril, simvastatin, pentoxifylline, and Humalog and Lantus insulin. He did not smoke. The patient had a temperature of 37.6°C and a grade II/VI systolic ejectionmurmur. He had necrosis and eschar formation involving his fingers (Figure 1A), toes (Figure 1B and C), and left posteriormedial calf (Figure 1D). He had violaceous skinwith central eschar on the posteriormedial aspect of his right leg (Figure 1E) thatwas exquisitely tenderwith gangrenous change.Hehadnormal femoral pulseswithnodistalpulsespalpable.Both feetwerewarmwithgoodDoppler signals in the dorsalis pedis and posterior tibial arteries. He had a palpable pulse and thrill in the brachiocephalic fistula in his left upper arm. There was also a weak distal radial pulse. He had good Doppler signals over the radial, ulnar, and palmar arch arteries bilaterally. Laboratory studies revealed awhite blood cell count of 13 900/μL (to convert to ×109 per liter, multiply by 0.001), a hemoglobin level of 7.7 g/dL (to convert to grams per liter, multiply by 10.0), a platelet count of 309 × 103/μL (to convert to ×109per liter,multiply by 1.0), an international normalized ratio of 2.4, a blood urea nitrogen level of 88 mg/dL (to convert to millimoles per liter, multiply by 0.357), a creatinine level of 9.9 mg/dL (to convert to micromoles per liter, multiply by 88.4), a calcium level of 7.5 mg/dL (to convert to millimoles per liter,multiply by0.25), an albumin level of 2.4 g/dL (to convert to grams per liter, multiply by 10), and an intact parathyroid hormone level of 349.7 pg/mL (to convert to nanograms per liter, multiply by 1.0). A skin biopsy specimen of the calf showed epidermal necrosis, dermal hemorrhage, focal dermal intravascular thrombi, and subcutaneous intravascular and extravascular calcifications. Quiz at jamasurgery.com A D E