[Use of ultrasonography in the diagnosis of cystic lesions in seminal vesicles and prostate].

Transrectal ultrasonography (TRUS) has been used extensively to evaluate the lower urinary tract in males, including the prostate gland, seminal vesicles and ejaculatory ducts. Of 475 males who underwent TRUS at Kitasato University Hospital, 43 (9.1%) were found to have cystic changes of these structures. Most of these cystic changes could be identified as being of prostate origin, Wolffian duct origin or Müllerian duct origin by their sonographic appearance and location. Although most patients were asymptomatic, 8 of the 30 men with a complaint of hematospermia had a sonographic finding of cystic changes in the prostate (3 patients) or ejaculatory ducts (5 patients). Inflammation and allergic reaction have been suggested to be related to hematospermia, however, their mechanism remains to unclear. These findings suggest that cystic changes in the ejaculatory duct contribute to hematospermia.