<P> A hydrocele feels like a small fluid - filled balloon inside the scrotum . It is smooth, and is mainly in front of the testis . Hydroceles vary greatly in size and are typically painless and harmless . However, as the fluid continues to accumulate and the scrotum further enlarges, more discomfort can be expected . Large hydroceles will cause discomfort because of their size . Sometimes pain can be in both testicles as pressure from the enlarged area puts pressure against the unaffected area which can cause discomfort to the normal testicle . It has also been found to decrease a man's sex drive and makes him less active for fear of enlarging the mass . As the fluid of a hydrocele is transparent, light shone through the hydrocelic region will be visible from the other side . This phenomenon is called transillumination . </P> <P> Symptoms of a hydrocele can easily be distinguished from testicular cancer, as a hydrocele is soft and fluid - filled, whereas testicular cancer feels hard and rough . </P> <P> A hydrocele testis is not generally thought to affect fertility . However, it may be indicative of other factors that may affect fertility . </P> <P> During embryogenesis, the testis descends through the inguinal canal, drawing a diverticulum of peritoneum into the scrotum as it descends . This peritoneal tissue is known as the processus vaginalis . Normally, the communication between the processus vaginalis and the peritoneum is obliterated, and the tunica vaginalis is the tissue that remains overlying the testis and the epididymis . Congenital hydrocele results when the processus vaginalis remains patent, allowing fluid from the peritoneum to accumulate in the scrotum . </P>

Puncture aspiration of left hydrocele of vas deferens