A 24-year-old man is being evaluated for gross hematuria. Cystoscopy under general anesthesia is performed. After the scope is passed into the urinary bladder, a triangular portion of the bladder floor formed by the internal urethral orifice and 2 slit-like openings is observed. Gross blood is seen oozing from one of the slit-like openings. Which of the following is the most likely cause of this patient's hematuria?
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The trigone is the triangular portion of the bladder formed by 2 slit-like ureteric orifices and the internal urethral opening. Bleeding from the ureter, as seen on this patient's cystoscopy, suggests an origin in the upper urinary tract (ie, kidney or ureter). In contrast, lower urinary tract bleeding (eg, trauma, infection) originates in the bladder or urethra, and the source is typically directly visualized upon insertion of a cystoscope through the urethra into the bladder.
The etiology of upper urinary tract bleeding is often identified based on other signs and symptoms, such as flank pain suggestive of a ureteral stone. Similarly, associated hypertension or proteinuria may indicate glomerular disease, and fever and pyuria are concerning for pyelonephritis.
In the absence of other findings, renal papillary necrosis (RPN) should also be considered as a cause of bleeding from the upper urinary tract. This condition is characterized by infarction of the renal medullary vessels, leading to sloughing of the renal papillae and gross hematuria. RPN is common with sickle cell nephropathy or can occur with analgesic use, obstructive uropathy, or diabetes mellitus. Bleeding is often painless and self-limited.
(Choices A and E) Hematuria originating in the bladder (ie, lower urinary tract) can be due to rupture or malignancy. However, bladder wall rupture would appear as an open perforation (not two slit-like openings) and bladder cancer presents with a mass on cystoscopy.
(Choice B) A colovesical fistula, which most commonly causes air bubbles and stool within the urine, is typically seen as an erythematous and edematous opening in the bladder wall. Although hematuria can occur with concomitant gastrointestinal bleeding, this patient's 2 slit-like openings within the triangular portion of the bladder are consistent with anatomic ureteric orifices.
(Choice D) Urethral diverticulum, another cause of lower urinary tract bleeding, is an outpouching of the urethra that would be visualized on cystoscopy prior to insertion into the bladder. In addition to postvoid dribbling and frequent urinary tract infections, hematuria can occur in this condition but would be present only in the urethra, not in the bladder or ureters.
Educational objective:
The bladder trigone is formed by 2 slit-like ureteric orifices and the internal urethral opening. Blood within the ureteric orifice suggests upper urinary tract bleeding originating in the kidney (eg, renal papillary necrosis) or ureter.