Renal pseudoaneurysm after calculous pyelonephritis.

INTRODUCTION: Renal pseudoaneurysms reportedly occur after partial nephrectomy, renal trauma, or percutaneous procedures. Renal pseudoaneurysms can also occur after renal inflammation; however, such cases are rare and seldom reported.

CASE PRESENTATION: A 53-year-old man presented to our emergency room with a 3-day history of fever and right back pain. A blood sample revealed severe inflammation and computed tomography showed an 8 mm diameter stone in the right middle ureter and hydronephrosis. The patient was diagnosed with calculous pyelonephritis and underwent emergency ureteral stenting and antibiotic therapy. On day 8 of hospitalization, hematuria and right back pain developed, and on day 9 bladder tamponade and anemia developed. Contrast-enhanced computed tomography revealed a ruptured pseudoaneurysm, and the patient underwent successful angioembolization. The patient was discharged on day 23.

CONCLUSION: We report a case of a renal pseudoaneurysm possibly caused by calculous pyelonephritis.