Man with left flank pain and diphoresis

A 63-year-old man with hypertension presented to the emergency department with sudden onset of pain in the left flank with diaphoresis after heavy lifting. His temperature, pulse rate, and blood pressure were 37°C, 80 beats/min, and 183/88 mmHg, respectively. Physical examination revealed left flank knocking tenderness. Blood laboratory tests revealed a leucocyte count of 13,920/µL, hematocrit level of 30.6%, hemoglobin level of 10 g/dL, and creatinine level of 1.77 mg/dL. Urine examination revealed gross hematuria. The emergency physician performed ultrasonography, which demonstrated left renal parenchyma collapse with compression by a huge hypoechoic hematoma (Figure 1), and the diagnosis was confirmed by computed tomography (CT) (Figure 2).