A 6 year old girl presents with Recurrent E.coli infection in urine. Ultrasound of abdomen shows Hydroureter and Hydronephrosis. Micturating cysto – urethrogam shows filling defect in urinary bladder. The likely diagnosis is –
Recurrent E. coli UTIs in a child often suggest an underlying structural abnormality. Hydroureter and hydronephrosis mean there's obstruction causing urine to back up. The MCU finding of a filling defect in the bladder points towards something inside the bladder causing the blockage.
The most common cause of a bladder filling defect causing obstruction in this age group is posterior urethral valves (PUV). These are congenital membranes in the male urethra, but the question mentions a girl. Wait, girls don't have posterior urethral valves. Oh, right, PUV is a male-specific condition. So maybe another cause?
Wait, the question says the MCU shows a filling defect. In a female, a filling defect in the bladder could be a bladder diverticulum with stasis leading to infection. But diverticula are less common. Alternatively, a bladder stone? But stones in children are rare unless there's a metabolic issue. Another possibility is a ureterocele, which is a cystic dilation of the ureter at the bladder outlet. Ureterocele can cause obstruction and recurrent infections. It's a congenital anomaly where the ureter ends in a small cyst that may block the bladder outlet. This would lead to hydronephrosis and hydroureter. The filling defect on MCU could be the ureterocele itself.
Wait, but the question is about a girl. Ureteroceles can occur in both genders. So the likely diagnosis here is a ureterocele. Let me check the options. The options aren't given, but the answer is probably ureterocele. The other options might include posterior urethral valves (which is male), bladder diverticulum, or vesicoureteral reflux. Vesicoureteral reflux (VUR) is a common cause of recurrent UTIs, but it doesn't cause a filling defect. VUR allows urine to flow back from bladder to kidneys, not a structural blockage. Bladder diverticulum might cause stasis but is less common. The MCU finding of a filling defect points more towards a ureterocele. So the answer is ureterocele.
**Core Concept**
This question assesses the differential diagnosis of recurrent urinary tract infections (UTIs) in children with imaging findings of hydronephrosis and a bladder filling defect. Key concepts include obstructive uropathy, congenital anomalies of the urinary tract, and the role of imaging in diagnosis.
**Why the Correct Answer is Right**
The most likely diagnosis is **ureterocele**, a congenital cystic dilation of the distal ureter at the bladder outlet. Ureteroceles obstruct urine flow, leading to hydronephrosis and hydroureter. In females, they often present with recurrent UTIs (e.g., E. coli) due to urinary stasis. On MCU, a ureterocele appears as a filling defect at the bladder base, confirming the obstruction. This condition is more common in males but can occur in females, especially when associated with duplicated collecting systems.
**Why Each Wrong Option is