Hydrocele testis
A hydrocele testis is an accumulation of clear fluid within the cavum vaginale, the potential space between the layers of the tunica vaginalis of the testicle. A primary hydrocele causes a painless enlargement in the scrotum on the affected side and is thought to be due to the defective absorption of fluid secreted between the two layers of the tunica vaginalis (investing membrane). A secondary hydrocele is secondary to either inflammation or a neoplasm in the testis. A hydrocele usually occurs on one side, but can also affect both sides. The accumulation can be a marker of physical  trauma, infection, tumor or varicocele surgery, but the cause is generally unknown. Indirect inguinal hernia indicates increased risk of hydrocele. Hydroceles are more common in boys than girls. A hydrocele is normally seen in infant boys as an enlarged scrotum. In infant girls it appears as enlarged labia. Signs and symptoms. 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. 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. Fertility. A hydrocele testis is not generally thought to affect fertility. However, it may be indicative of other factors that may affect fertility. Cause. 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, allowing fluid from the peritoneum to accumulate in the scrotum. Diagnosis. Through diagnostic ultrasound the accumulation of fluids can be diagnosed correctly. Treatment. The fluid accumulation can be drained by aspiration, but this may be only temporary. A more permanent alternative is a surgical procedure, generally, an outpatient ambulatory (same-day) procedure, called a hydrocelectomy. There are two surgical techniques available for hydrocelectomy. If the hydrocele is not surgically removed, it may continue to grow. The hydrocele fluid can be aspirated. This procedure can be done in a urologist's office or clinic and is less invasive, but recurrence  rates are high. Sclerotherapy, the injection of a solution following aspiration of the hydrocele fluid may increase success rates. In many patients, the procedure of aspiration and sclerotherapy is repeated as the hydrocele recurs.