Seminal vesicle cyst
Seminal vesicle cysts can be congenital or acquired.
It is the presence of cysts within the seminal vesicles since birth. It is seen rarely and occurs probably due to an obstruction at the junction of the seminal vesicle and ejaculatory duct. It is associated with many other urogenital anomalies:
- renal agenesis or dysgenesis 1
- ectopic insertion of ureter into seminal vesicle, ductus deferens, ejaculatory duct or prostatic urethra
- ductus deferens agenesis
This occurs secondary to the obstruction of the seminal vesicle causing cystic dilatation.
- obstruction by benign prostatic hypertrophy
- chronic infection and scarring of the seminal vesicle or ejaculatory duct
- prior prostate surgery
Congenital cysts occur due to insufficient drainage as a result of atresia of the ejaculatory ducts causing distension of seminal vesicles and further leading to the formation of a cyst. They usually become symptomatic in young adulthood due to the accumulation of secretions. These cysts are mostly unilateral with no predilection for side of involvement
Acquired cysts are seen most often secondary to prostatic infection or surgery causing scarring and finally obstruction of the drainage of secretions. This is seen most often bilaterally.
Age of presentation of congenital cysts is during the period of greatest reproductive activity i.e in 2nd and 3rd decades of life while acquired cysts are most often seen in the elderly age group. Smaller cysts may be detected incidentally. In symptomatic patients, the usual presenting features include perineal pain, abdominal pain, ejaculatory pain, dysuria, haematuria, increased frequency of micturition, urinary tract infections and infertility.
Seminal vesicles appear normal or enlarged in size with presence of cysts within.
These can be imaged by transabdominal ultrasound and best evaluated by Transrectal ultrasound. The cysts may be anechoic or may contain internal debris from haemorrhage or infection.
Larger cysts may be seen on CT. The cysts may be seen as well defined, low attenuation lesions or thick and irregular walled cysts with hyperdense contents in cases of secondary haemorrhage or infection. These lesions are classically located in the retro-vesicular region and cephalic to prostate. The associated renal anomalies can be depicted well.
Best in differentiating cystic pelvic lesions. Abdominal and pelvic anatomy can also be assessed. Classical appearance of cysts is maintained with low T1 and high T2 weighted signal intensity. Some seminal vesicle cysts may have high T1 and T2 signals probably due to proteinaceous contents or haemorrhage.
Depending on the size of the seminal vesicle cyst, surgery may be done.
Other causes of male pelvic cystic masses can be included as a differential diagnosis.
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- 2. Gorrea M, Lorente R, Roel J. Seminal vesicle cyst associated with ipsilateral renal agenesis and papillary carcinoma of the bladder. Eur Radiol. 2001;11 (12): 2500-3. doi:10.1007/s003300000815 - Pubmed citation
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- 4. King BF, Hattery RR, Lieber MM et-al. Congenital cystic disease of the seminal vesicle. Radiology. 1991;178 (1): 207-11. Pubmed citation