Congenital anterior urethral diverticulum: Sonographic diagnosis

J Clin Ultrasound 24:543-544, NovemberiDecernber 1996 6 1996 by John Wiley & Sons, Inc. CCC 0091-27511961090543-02

Case Report

Congenital Anterior Urethral Diverticulum: Sonographic Diagnosis Mayank Goyal, MD," Raju Sharma, MD,* Devendra Kumar Gupta, MSt Aseem Sharma, MD,* and Manorama Berry, ML)*

Congenital anterior urethral diverticulum is a rare abnormality. We present a case of a large wide-mouthed urethral diverticulum diagnosed by ultrasound. Complete diagnostic information was possible on sonography. CASE REPORT

A 15-month-old boy presented to the hospital with a history of post-void dribbling since birth. There were no obstructive symptoms nor evidence of discomfort during micturition. There was no history of urethral instrumentation, trauma, or infection. In addition, the parents had noticed swelling of the distal penis during micturition which was more pronounced on the ventral aspect. The swelling reduced in size some time after micturition. On examination, the penis was seen to be normal in appearance, and the kidneys and bladder were not palpable. During micturition, a swelling was seen on the ventral aspect of the shaft of the penis. Pressure on the swelling caused dribbling of urine from the urethra. Sonographic evaluation of the urethra was performed using a focused 5 MHz linear array transducer [Advanced Technology Laboratories (ATL)-UM-9]. The probe was placed on the dorsal aspect of the penis. The urethra was collapsed, and no abnormality was seen. During micturition, an anechoic space in communication with the urethra was seen to fill up on the ventral aspect, suggestive of a n anterior urethral diverticulum. The diverticulum retained urine for some time after micturition. To better evaluate the lesion, we performed retrograde sonourethrogra~

From the Departments of *Radiodiagnosis and tPediatric Surgery, All India Institute of Medical Sciences, New Delhi, India. For reprints contact Dr. Raju Sharrna, Department of Radiodiagnosis, All India Institute of Medical Sciences, New Delhi 110 029. India. VOL. 24, NO. 9, NOVEMBERIDECEMBER 1996

phy -saline was injected through a catheter, the tip of which was placed in the urethra, while the ultrasound scan was performed. This technique better displayed the diverticulum, demonstrated its communication with the urethra, and delineated the size of the neck of the diverticulum. In addition, the shape of the distal lip of the diverticulum could be evaluated both during micturition and during controlled distention of the diverticulum. Ultrasound of the kidneys and urinary bladder was normal. The findings were confirmed subsequently on micturiting cystourethrography (MCU). The patient underwent open diverticulectomy and urethroplasty and is asymptomatic on follow-up.

DISCUSSION

Congenital anterior urethral diverticulum is a rare abnormality. These diverticulae are usually located on the ventral aspect of the anterior urethra.' They may present with dribbling, hematuria, dysuria, urinary tract infection, or urinary obstruction. A small diverticulum may be asymptomatic.' The diverticulum may be palpable as a small swelling on the ventral aspect of the penis, .~ especially at the end of m i ~ t u r i t i o n Patients with urinary obstruction generally present during infancy; subsequently, dribbling of urine is the most frequent ~ o m p l a i n t . ~ Congenital anterior urethral diverticulae are of three types: wide-mouthed diverticulae, narrow-mouthed diverticulae, and megalourethra, which is a generalized dilatation of the entire anterior ~ r e t h r a The . ~ wide-mouthed diverticulae a r e usually saccular in shape, t h e narrowmouthed diverticulae are mostly ~ p h e r i c a l .A~ wide-mouthed diverticulum may or may not have a distal lip.6 As urine fills the diverticulum during voiding, the distal lip elevates and presses against the urethra causing o b ~ t r u c t i o n .In ~ the 543

CASE REPORT: GOYAL ET AL.

FIGURE 1. The diverticulum is seen on sonourethrography (arrow). Evaluation of the neck and distal lip is possible. Note the catheter i n the urethra (arrowhead).

FIGURE 3. Conventional MCU confirms the presence of an anterior urethral diverticulum (-). The remainder of urethra is normal. An incidental bladder diverticulum I S seen.

especially in the age group of the majority of patients. We also feel that sonourethrography would be better in evaluation of the functional deficit produced by a distal lip. To conclude, sonourethrography can provide complete diagnostic information in a patient of suspected congenital anterior urethral diverticulum. REFERENCES FIGURE 2. The diverticulum retains fluid for some time after micturition.

present case, the diverticulum was spherical in shape. However, the neck was relatively wide. The role of imaging in a suspected congenital anterior urethral diverticulum is confirmation of diagnosis, evaluation of its size and neck and determination of the presence or absence of a distal lip. Conventional urethrography has been the mainstay for evaluation of this condition. However, in the case under report, we could provide adequate diagnostic information using sonography. In addition, the technique could be better controlled by using retrograde sonourethrography. The absence of radiation is of significance,

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