Presentation
Purulent urethral discharge.
Patient Data
There is a complete duplication of the left renal collecting system.
The ureter of the superior system presents an ectopic insertion at the prostatic urethra resulting in a marked dilatation of the upstream collecting system with secondary chronic renal parenchymal impact (thinning of the overlying upper renal parenchyma and absence of excretion of the superior calyx).
There is also a diffuse urothelial wall thickening of the left upper system ureter with post-contrast enhancement and periureteric fat stranding (ureteritis).
The inferior left collecting system presents a normally inserted ureter with no dilatation and no stones.
The right kidney and ureter are unremarkable.
Other findings : enlarged prostatic gland, left upper calyx microlithiasis and inferior left renal parapelvic simple cyst.
Annotated image: the blue arrow indicates the ectopic insertion of the left ureter into the prostatic urethra.
Case Discussion
CT features of duplex left kidney with ectopic ureter.
Ectopic ureter is a congenital renal anomaly. Normally the ureter drains via the internal ureteral orifice at the trigone of the urinary bladder.
In males, the ureter may insert into the lower urinary bladder, posterior urethra, seminal vesicle, ductus deferens, ejaculatory duct, and rarely the rectum.
In females, the most common sites for ureter insertion are the bladder neck and upper urethra (33%), vaginal vestibule between the urethra and introitus (33%), vagina (25%), and cervix and uterus (<5%).