Classification of cystic structures located at the midline of the prostate: our experience

Between January 1994 and February 2002, 9086 men underwent biplane TRUS at our institution for a variety of reasons. 781 of the 9086 men (8.6%) showed evidence of one or more intraprostatic cystic lesions. We propose a new classification of cystic structures located at the midline of the prostate.

We have designed a methodology that reclassifies cystic structures located at the prostate midline through the ultrasonically guided transrectal aspiration of the cystic structure, the analysis of the PSA level of the aspirated fluid and the presence of spermatozoa, radiological studies (cyst injection with contrast medium, vasography, retrograde and/or voiding cystourethrography and utricle injection with contrast medium) and endoscopic studies (cystourethroscopy).

Upon completion of the methodology, we have classified and defined these structures as the following: simple prostatic cysts, cysts of the müllerian ducts, megautricle, megautricle with inclusion of the ejaculatory ducts, "pseudocystic" dilation of the ejaculatory ducts and utriculoceles.

This new classification of cystic structures located at the prostate midline is simple, useful and steers one away from any possible confusion.