Presentation
Right flank pain that has been ongoing for the last two weeks. She presents with dysuria, fever as well as ongoing nausea.
Patient Data
Technique: Single phase multi bolus IV contrast enhanced polychromatic SPECTRAL CT
Findings:
Kidneys: The right kidney is engorged with marked pelvicalyceal and ureteric distension which is thick walled and enhanced, likely in keeping with secondary infective change, all secondary to an obstructing 3 mm calculus of the distal right ureter. Right side perinephric fat standing and a small amount of fluid tracking into the pelvis in keeping with a secondary urinoma. Left kidney and ureter define normally. Bilateral small simple appearing renal cysts. Normal liver, spleen, pancreas, small bowel, large bowel, omentum, mesentery and adrenals. There are no radiopaque stones in the gallbladder. The common bile duct and portal vein are of normal caliber. Small volume of urine is noted within the bladder. Nil free fluid or free gas. No inguinal or femoral hernia. Lung bases are clear. No acute vasculopathy.
In summary:
Obstructive pyelonephritis of the right kidney secondary to a 3 mm distal right ureteric calculus with secondary urinoma tracking into the pelvis.
Annotations:
- Purple arrows: urinoma secondary to obstructive pyelonephritis of the right kidney.
- Green arrows: pelvicalyceal distension (caliectasis) likely in keeping with secondary infective changes due to obstructing calculus.
- Yellow arrow: 3 mm distal right ureteric calculus.
- Blue arrow: urinoma tracking to the Pouch of Douglas.
Case Discussion
Learning points:
- Urinoma is a collection of urine outside the urinary tract. They occur due to the disruption of the collecting system of the kidneys 1,2.
- Causes of urinoma include blunt or penetrating traumas, upper urinary tract instrumentation, obstructive urinary stones and rarely rupture of the cortical cysts. The patient in this case developed urinoma secondary to obstructive renal stone 1,2.
- This patient had an initial clinical diagnosis of pyelonephritis. The findings of the CT confirmed a diagnosis of obstructive pyelonephritis complicated with urinoma. This showcases the importance of early CT in patients presenting with suspected renal calculus or complicated pyelonephritis 1.
- Delay in the diagnosis of urinoma can lead to increased morbidity. Infected urinoma can be complicated by retroperitoneal abscess 1,2. In the literature, it is reported that ultrasound scans can miss urinoma which can delay management, therefore CT scan is ideal 1. The patient was referred to hospital straight away after scan for definitive management.
Case courtesy of Dr Zane Sherif.