Challenging Case: UTI and undetected genitourinary anomalies

MRI solid kidney vesicoureteral reflux hydronephrosis
MRI revealing the lack of a right kidney, as well as hydronephrosis of the left kidney.

A 3-year-old boy initially presented with a 10-day history of intermittent fevers—fluctuating as high as 105°F—and abdominal pain. His abdominal pain was episodic (lasting 30-60 minutes and occurring 2-3 times per day) fairly severe, peri-umbilical, non-radiating, and worsened with fevers. Initial evaluation revealed largely unremarkable labs (wbc 11.3, urinalysis normal). The patient was admitted to the hospital overnight but cultures and other workup were negative. No imaging was obtained at that time. As his fevers and abdominal pain resolved during the hospital stay, he was discharged home with presumed diagnosis of sequential viral infections.

Three days later he presented again a fever of 104°F and recurrent abdominal pain. Urinalysis and cultures were again negative. This time, abdominal sonography was obtained, showing a solitary left kidney with hydroureteronephrosis and a cystic area posterior to the bladder. The Boston Children’s Hospital Department of Urology was called into consult, after which an MRI confirmed right renal agenensis, left hydroureteronephrosis and a presumed right seminal vesicle cyst. Debris within the cyst was thought most likely due to hemorrhage in the lumen. Multiple wedge-shaped cortical perfusion defects of the solitary left kidney were observed, most consistent with pyelonephritis.

A voiding cystourethrogram (VCUG) showed grade IV vesicoureteral reflux (VUR) without obstruction and a possible small left peri-ureteral diverticulum. No contrast filling or communication with the right seminal vesicle cyst was observed. Despite negative repeat urinalysis and urine and blood cultures, based on the MRI findings the decision was made to treat presumptively for pyelonephritis (IV ceftriaxone followed by a 10 day course of oral cefixime, followed by prophylactic trimethoprim/sulfamethoxazole).

Three months after his initial presentation the patient underwent a cystoscopy—which showed a normal urethra and bladder neck without evidence of communication to any seminal vesicle cyst—and left ureteral reimplantation. As the seminal vesical cyst was not thought to be a likely source of his intermittent fevers, given the renal findings on MRI, it was not excised. Post-operative VCUG 4 months later showed resolution of his VUR and a normal bladder and urethra. Over the 18 months since surgery, he has done well without recurrent fevers or UTI.

VCUG vesicoureteral reflux hydronephrosis
Pre- (left) and post-operative (right) voiding cysturethrograms.

Lessons learned

This case shows an atypical, delayed presentation of substantial genito-urinary anomalies in the setting of presumed UTI. Although we might assume that such anomalies would be picked up on antenatal sonographic screening, this patient reportedly had “normal” ultrasounds at 20 weeks gestation. Such occurrences are common and in pediatric urology we routinely see such “missed” anomalies. Thus, tales of supposedly normal prenatal imaging should always be taken with the proverbial grain of salt, particularly in children with clinical genitourinary illness such as UTI.

This boy’s presentation was made particularly challenging by the repeated normal urinalyses, which sensibly diverted suspicion from the urinary tract. In hindsight, however, persistent abdominal pain in the setting of recurrent fevers would have justified earlier abdominal sonography, which would have identified the genitourinary abnormalities earlier in the clinical course.

Caleb Nelson kidney stone urology vesicoureteral reflux hydronephrosisCaleb Nelson, MD, MPH, is co-director of the Kidney Stone Program and director of quality and safety in Boston Children’s Department of Urology.

MRI and VCUG images courtesy of Jeanne Chow, MD, of the Boston Children’s Department of Radiology.

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