Perinephric Capsular Haematoma Associated with Complicated Pyelonephritis in a Patient with HIV.

A 53 year-old-male patient presented with 24 hours of left flank pain. He was an undiagnosed HIV positive individual with no history of trauma. He was anaemic and in acute renal failure with a serum creatinine of 4.14 mg/dL. A CT scan demonstrated a left perinephric capsular haematoma with retroperitoneal stranding. Due to haemodynamic instability, the patient was taken to the operating room and a nephrectomy was performed. Post-operatively, the patient required temporary haemodialysis. Pathologic examination of the specimen demonstrated active infection with a haematoma surrounding a fistulous tract communicating with the capsular surface. Infection is a rare cause of non-traumatic capsular hematomas of the kidney.