Pictured: CT abdomen with contrast showed a new large left retroperitoneal hematoma measuring 17 x 9.3 x 8.2 cm. CT abdomen with contrast (see Figure 1) showed a new large left retroperitoneal hematoma measuring 17 x 9.3 x 8.2 cm) with active contrast extravasation at the left iliacus and iliopsoas muscle. CT angiogram was performed and showed an enlarging left retroperitoneal hematoma with active extravasation. The patient’s serum creatinine had increased from a baseline of 1.5 mg/dL on admission to 5.2 mg/dL on hospital day 4 (the day after diagnosis of retroperitoneal hematoma). A retroperitoneal hematoma can occur spontaneously or in association with trauma or surgery.