Case Report #0584

1. Radiological Category: Genitourinary Principal Modality (1): Principal Modality (2): CT CR Case Report #0584 Submitted by: Heng-Hsiao Liu, M.D. Faculty reviewer: Stanford Goldman, M.D. Date accepted: 15 March 2009

2. Case History 40 year old male with no past medical history status post motor vehicle collision.

3. Radiological Presentations Coronal enhanced CT

4. Radiological Presentations Delayed axial enhanced CT

5. Test Your Diagnosis Which one of the following is your choice for the appropriate diagnosis? After your selection, go to next page. • Transitional cell carcinoma • Ureterocele • Urinary calculus • Bladder diverticulum

6. Additional Images Oblique pelvic radiograph during contrast excretion

7. There is cystic dilatation and telescoping of the distal left ureter into the bladder, best seen on delayed images, with proximal hydronephrosis of the left kidney. No calculus or soft tissue density is identified at the ureteropelvic junction. Pelvic radiograph revealed the classic “cobra head” sign, a contrast-filled ureter draining into the bulbous dilatation of its distal end with a surrounding radiolucent halo seen within the bladder. These findings are consistent a simple ureterocele. Findings

8. Differentials • Transitional cell carcinoma • Urinary calculus • Bladder diverticulum • Urachal cyst

9. A ureterocele is defined as a cystic dilatation of a prolapsed, intravesical segment of the distal ureter. This may be due to a congential narrowing of the ureteral meatus, which then dilates and eventually prolapses into the bladder. Inflammation or trauma leading to fibrosis of the ureteral meatus later in life may also precede the development of a ureterocele. Adult-type ureteroceles are more common in women. Discussion Fig 1. Simple uretocele. Berrocal et. al. (1)

10. Ureteroceles are classified as simple or ectopic. In simple ureteroceles, the orifce of the ureter and the ureterocele itself are intravesical. They are incidental findings in asymptomatic adult patients, but when large, they can cause obstruction of the bladder neck along with obstruction of the ipsilateral ureter. The ectopic ureterocele lies within the submucosa of the bladder, and some part of it may extend into the bladder neck or urethra. It is usually diagnosed in childhood and almost always seen in association with duplex ureters, typically arising from the upper pole ureter. Discussion Fig. 2. Prolapsed ureterocele. Berrocal et. al. (1)

11. Fig. 3. Sonographic findings are characteristic, usually seen as a rounded, sonolucent mass with echogenic walls that projects into the bladder. Berrocal et. al. (1) Discussion

12. An important differential consideration is pseudoureterocele, which is defined as an incomplete distal ureteral obstruction associated with a tumor or calculus. Stone impaction at the ureteropelvic junction with surrounding edema or tumor overgrowth at the distal ureter may both present with the classic “cobra head” sign. Therefore, one must carefully inspect the “cobra’s hood” for focal areas of thickening, irregularity, or loss of definition. Other suspicious findings include irregularities of the bladder wall, moderate to severe obstruction of the proximal ureter, or stones elsewhere in the urinary tract. Cystoscopic evaluation may be helpful in difficult cases. Discussion Fig. 4. Impacted ureteral stone. Dyer et. al. (3) Fig. 5. Transitional cell carcinoma. Dyer et. al. (3)

13. Additional Images Axial CT Lung Window

14. Additional Images Axial CT Lung Window

15. Additional Images Axial enhanced CT

16. Additional Images Cystogram

17. CT revealed a small amount of free air in the abdomen and a tiny amount of free fluid in the pelvis. The bladder was decompressed with a Foley but otherwise unremarkable. No pelvic fractures were identified. A cystogram performed to work-up the patient’s hematuria revealed intraperitoneal bladder rupture. Intraoperatively, no bowel injury was seen. It is suspected that the Foley drained most of the free fluid in the pelvis and introduced a small amount of air. Findings

18. Bladder injury may result from blunt or penetrating trauma, and the propensity for rupture is related to the degree of distension at the time of impact. Delayed diagnosis may significantly increase mortality. Bladder injury is classified into five types: 1 – Contusion 2 – Intraperitoneal 3 – Interstitial 4 – Extraperitoneal 5 – Combined intraperitoneal and extraperitoneal Discussion Fig. 6. Type 2 bladder rupture. Vaccaro et. al. (4)

19. Types 1 & 3 are managed conservatively; type 4 needs catheter drainage; types 2 & 5 require surgical treatment. CT with intravenous contrast is inadequate to diagnose bladder injury as there is inadequate distension from the antegrade flow of contrast from the ureters. A retrograde cystogram or CT cystography can be performed to assess for bladder injury, which may be suspected in the presence of pelvic fractures, intraperitoneal free fluid, or gross hematuria. Discussion Fig. 7. Contrast between bowel loops in a type 2 bladder injury. Vaccaro et. al. (4)

20. Intraperitoneal Bladder Rupture with Left Simple Ureterocele Diagnosis

21. 1. Chavhan GB. The cobra head sign. Radiology. 2002 Dec;225(3):781-2. 2. Berrocal T, López-Pereira P, Arjonilla A, Gutiérrez J. Anomalies of the distal ureter, bladder, and urethra in children: embryologic, radiologic, and pathologic features. Radiographics. 2002 Sep-Oct;22(5):1139-64. 3. Dyer RB, Chen MY, Zagoria RJ. Classic signs in uroradiology. Radiographics. 2004 Oct;24 Suppl 1:S247-80.4. Vaccaro JP, Brody JM. CT cystography in the evaluation of major bladder trauma. Radiographics. 2000 Sep-Oct;20(5):1373-81. 5. Sandler CM, Hall JT, Rodriguez MB, Corriere JN Jr. Bladder injury in blunt pelvic trauma. Radiology. 1986 Mar;158(3):633-8. References