On initial examination, the patient had a 3.0 × 4.0-cm ulcer with eschar and surrounding induration and violaceous discoloration on his right thigh. On his left thigh, there was a 2.5-cm × 4.0-mm linear hemorrhagic crust. In addition, he had violaceous discoloration in a livedo reticularis pattern over his lower extremities bilaterally. Laboratory evaluation on admission included the following findings: his calcium level was 7.9 mg/dL (2.0 mmol/L); phosphorus level, 5.5 mg/dL (1.8 mmol/L); albumin level, 3.3 g/dL; urea nitrogen level, 39 mg/dL (13.9 mmol/L); creatinine level, 4.0 mg/dL (305.0 μmol/L); intact parathyroid hormone level, 1080 pg/mL (reference range, 7-53 pg/mL); 25-hydroxyvitamin D level, 10.0 ng/mL (25.0 nmol/L) (reference range, 20-57 ng/mL [49.9-142.3 ng/mL]); and 1,25-dihydroxyvitamin D level, 11.1 pg/mL (28.9 pmol/L) (reference range, 15.9-55.6 pg/ml [41.3-144.6 pmol/L]). The calcium-phosphorus product was 43.5 mg/dL. Findings from an excisional biopsy of the right thigh ulcer showed focal ulceration with fibrinoid and hemorrhagic exudate. There were also numerous small vessel thrombi and deposits of calcium present within the deep blood vessel walls. These histologic findings indicated a diagnosis of calciphylaxis.