Emphysematous pyelonephritis initially presenting as a spontaneous subcapsular hematoma in a diabetic patient

Emphysematous pyelonephritis (EPN) is a life-threatening infection characterizedby the formation of gas. Complications of EPN include septic shock, acuterenal failure, and disseminated intravascular coagulation. Spontaneous subcapsularhematoma (SCH) has also been reported as a rare complication of EPN, althoughthere have been no reports to date of this occurring prior to the presentation of EPN. We report a case of EPN that initially presented as spontaneous SCH. The patientwas admitted for left flank pain, and initial computed tomography revealed SCHwithout any air shadows. Laboratory findings and clinical symptoms suggested thepresence of urinary tract infection and the patient was started on antibiotics. Feverdeveloped 24 hours after admission. On follow-up computed tomography 7 dayslater, EPN was newly observed, and a percutaneous drain was inserted. Blood, urine,and drainage fluid cultures all revealed growth of extended-spectrum β-lactamasenegativeEscherichia coli.