Teaching Case

Young man with known systemic lupus erythematosus on long-term corticosteroid therapy plus plaquenil, currently suffering from lumbar pain, dysuria and macroscopic haematuria. Physically found afebrile, with left flank and pelvic tenderness but no peritonism.
No significant abnormalities of routine laboratory tests including acute phase reactants and renal function.

Urgent ultrasound (Fig.1) showed a demarcated 5-cm echogenic mass at the left posterolateral aspect of the urinary bladder, with upstream hydronephrosis. Cystoscopy confirmed bloody urine and a large intravesical roundish mass with mildly inflamed overlying mucosa, initially interpreted as submucosal tumour.
When planning further investigation, a CT (Fig.2) obtained three years earlier was found in the Picture Archiving and Communication system (PACS), which diagnosed a thin-walled left intravesical ureterocele with a stone at the uretero-vesical junction, ipsilateral mild hydronephrosis, and a 6-mm calyceal calculus. These findings did not lead to treatment.
Comparison with the previous study proved very helpful to elucidate the current CT-urography appearance (Fig.3): the left ureterocele was increased in size with thickened hyperattenuating (50-60 Hounsfield Units) walls and containing a calculus, interpreted as haemorrhagic complication. Ipsilateral hydronephrosis was confirmed, with a second stone at the ureterovesical junction and migrated previous calyceal stone.
Elective ureterocele resection was planned after medical therapy.

Corresponding to a submucosal saccular dilatation of the intramural ureter which prolapses into the urinary bladder, ureterocele is a developmental abnormality resulting from congenital weakness of the lower ureteral wall and narrowed distal meatus. Compared to heterotopic ureteroceles with ectopic ureteral orifice and duplicated renal collecting system which are typical of the paediatric age group, single-system “adult” orthotopic ureteroceles (AOUs) with a normal insertion into the bladder trigone are rarely associated with renal dysplasia, obstruction, reflux and abnormal renal function, and are often incidentally detected in young adults (mean age 31 years; range 20-49 years). The AOU wall consists of three layers, namely ureteral epithelium and bladder urothelium separated by connective tissue and muscle. In normal conditions, cystoscopy visualizes the AOU with smooth walls covered by normal mucosa [1-3].
Albeit commonly asymptomatic, AOU may manifest with variable symptoms such as flank or back pain, fever, voiding dysfunction and haematuria, resulting from superimposition of urolithiasis, obstruction or urinary infection. Whereas ureteroceles predominate in females (4-7:1), AOU-related stones tend to be more common in males. Occasionally, a long-standing calculus which cannot pass the narrow ureteral orifice may cause mural oedema, ischaemia, pressure necrosis and haemorrhage of the AOU. In this exceptional case, the complicated AOU resulted in a large, bleeding filling defect at both endoscopy and ultrasonography, which raised the suspicion of tumour [1-4].
In the patient reported here the use of CT provided the correct diagnosis by recognition of the characteristic site of an AOU protruding into the bladder lumen at the distal ureteral orifice. An uncomplicated ureterocele is heralded by the classical “cobra head” sign described at intravenous pyelography contrast-enhanced CT and MR-urography. Compared with the normal thin, uniform nonenhancing walls, haemorrhagic AOU is depicted with preserved usual and regular contour, and thickened hyperattenuating periphery reflecting intramural haemorrhage [4, 5]. Furthermore, CT allows comprehensive diagnosis of coexistent lithiasis, upstream hydronephrosis and renal function and aids in the differential diagnosis from transitional cell carcinoma and other non-neoplastic bladder lesions [5-8].
Surgical treatment is required for symptomatic or complicated AOUs, to prevent sepsis and renal function deterioration. Transurethral unroofing represents the preferred first-line approach. Other options such as ureteropyelostomy, ureterocele excision with ureteral reimplantation, and nephroureterectomy are reserved for complex cases [1-4].