Spontaneous rupture of pyonephrosis presenting as anterior abdominal wall abscess: a rare case report

Abstract

Background: A pyonephrosis caused by an obstructing calculus is typically accompanied by fever, loin pain, and other signs of urinary tract infection. Occasionally, severe thinning of the renal parenchyma in pyonephrosis allows direct forniceal rupture into the retroperitoneum and very rarely into the anterior abdominal wall, misconstruing it as an isolated abdominal wall abscess. Case presentation: Diabetes-related 55-year-old diabetic male presented with abscess in his periumbilical region extending into right lumbar region. He did not exhibit any urinary symptoms, and contrast enhanced computed tomography [CECT] abdominal and pelvic examinations revealed right pelvic calculus with pyonephrosis. There is a 7.5 mm defect in the lower pole of the right kidney with 171 cc of collection adjacent to the kidney communicating with 150 cc of superficial abdominal wall collection through a 15 mm defect. Incision and drainage of abdominal and retroperitoneal abscesses were done at first. Right DJ stenting was performed. Right lateral decubitus was placed for dependent drainage. Resolution of residual collections was confirmed by subsequent ultrasonography KUB, and drain was then removed. Right DJ stenting done, and patient was discharged. Two months later, DTPA scan done and revealed GFR of 30 ml/min of right kidney. Patient underwent right percutaneous nephrolithotomy. Conclusion: The sudden rupture of pyonephrosis is a rare event. Even rarer is the presentation of pyonephrosis as an abscess on the anterior abdominal wall. The correct diagnosis and search for the source of the abscess must be undertaken before intervention. An aggressive and prompt management is needed to prevent further complications from occurring. This case is being presented to add to the literature with regard to abnormal presentations of ruptured pyonephrosis and its management.