Prostatic utricle cyst

Case contribution: Dr Radhiana Hassan

Clinical:

  • A 27 years old man
  • Presented with recurrent painless hematuria for the last 10 years.
  • US KUB showed no evidence of renal / ureteric calculus.
  • CT KUB showed persistent small focal hypodense lesion at posterior prostate.
  • MRI for further characterization of the lesion.
MRI pelvis in axial plane T2-weighted images
MRI pelvis in sagittal plane T1+Gadolinium and T2-weighted images

MRI findings:

  • A small focal midline cystic prostatic lesion is noted (yellow arrows), located within the mid-posterior transition zone.
  • It measures at 0.9 cm x 0.6 cm x 1.8 cm (AP x W x CC).
  • The lesion returns hypointense signal on T1 and hyperintense on T2. Minimal rim enhancement observed following IV gadolinium. No restricted diffusion is observed.
  • It shows continuation with the prostatic urethra.
  • Seminal vesicles are normal.
  • The prostate gland itself is normal in size.
  • The urinary bladder is normal.

Diagnosis: Prostatic utricle cyst

Discussion:

  • Prostatic utricle is a remnant of Mullerian duct in males.
  • Prostatic utricle cyst results from focal dilatation of the prostatic utricle ranging from few millimeters to 2 cm.
  • The incidence of prostatic utricle cyst is 11% to 14% in association with hypospadias or intersex anomalies and up to 50% in the presence of perineal hypospadias.
  • It is usually seen during the first to second decades of life, with a mean age range of 26 years.
  • Most prostatic utricular cysts are asymptomatic.
  • When symptomatic it typically consist of urinary incontinence, recurrent infections, or stone formation.
  • Malignant degeneration has been reported in 3% of prostatic utricles.
  • On ultrasonography, a well-defined midline cystic lesion is seen posterior to the urinary bladder.
  • MRI shows  as a cystic lesion in the substance of the prostate gland posterior to the urinary bladder with a typical midline location. Communication of the cyst with the prostatic urethra is typically noted.
  • The differential diagnosis to be considered on imaging appearance include bladder diverticulum, urachal cyst, Mullerian duct cyst, or a seminal vesicle cyst.
    • Prostatic utricle cyst communicates with the prostatic urethra and are located in the midline, posterior to the bladder, and anterior to the rectum, as described in this case.
    • Mullerian duct cysts, on the other hand, do not typically communicate with the prostatic urethra, although they are also midline.
    • Urachal cysts are clearly distinguished from a prostatic utricle cyst due to their anterior relationship to the urinary bladder while seminal vesicle cysts are located lateral to midline and are usually unilateral.
Author: radhianahassan