When there is deficient secretion or resistance to Müllerian inhibitory factor (MIF), there is failure of normal fusion of the urogenital folds resulting in hypospadius.   Hypospadius has the most common association with the prostatic utricle, with an estimated incidence of 14-47%. In the absence of other Müllerian duct derivatives (fallopian tubes, uterus and upper vagina), hypospadius and utricular enlargement are not indicative of an intersex condition. The increasing severity of the hypospadius correlates with increasing size of the utricle.  A utricle not uncommon in prune-belly syndrome, and may be seen in patients with imperforate anus and recto-urethral fistula, and in patients with Down syndrome.

 

The prostatic utricle distends with urine during voiding and then passively drains. Poor emptying leads to urine retention and stasis. Stone formation may result from obstruction. Patients present clinically with chronic urinary tract infection, hematuria, urethral discharge, epididymitis and voiding dysfunction.

 

The normal prostatic utricle is occasionally seen as an incidental finding on routine VCUG as a tiny diverticulum of a few millimeters in length or on rare occasions measuring up to 1 cm or more. A large prostatic utricle is more often associated with male hypospadius. VCUG and retrograde urethrography (RUG) define the utricular size and its origin from the prostatic urethra. Occasionally a prostatic utricle is bifid, reflecting the bifid nature of its precursors, namely the paired Müllerian ducts. In patients with a large prostatic utricle, direct catheterization of the bladder during VCUG may be difficult secondary to preferential passage into the utricle. Facilitation of catheter placement into the bladder can be accomplished with use of a Coude' catheter with the tip directed anteriorly, direct perineal pressure and/or insertion of a finger in the rectum with upward pressure during catheter placement.

 

Differential Diagnosis

 

1. Ectopic ureter.  2. Dilated ejaculatory duct.  3. Mullerian duct cyst.

4. Extravasation

  

Treatment

 

Surgical excision is the treatment of choice for symptomatic utricular cysts. Surgical management is challenging due to the close proximity of the ejaculatory ducts, pelvic nerves, vas deferens and ureters. Perineal, suprapubic extravesical, transperitoneal, parasacral, transvesical transtrigonal, retropubic, posterior and anterior sagittal and transanorectal approaches have all been described. Non-surgical treatments include transurethral cyst catheterization and aspiration, cyst orifice dilation, unroofing, sclerotherapy and electrofulguration.  Complications include incomplete excision, impotence and rectal injury.

 

References:

1. Bates DG., “The Bladder and Urethra”. Caffey’s Pediatric Diagnostic Imaging. Eleventh Edition.  In print.

2. Krstic ZD et al. Surgical Treatment of the Mullerian Duct Remnants. Journal Pediatric Surgery, Vol 36, No 6 (June), 2001: pp 870-876