Hydrocele

What it is

A hydrocele is a collection of serous fluid that results from a defect or irritation in the tunica vaginalis, and on US it is an anechoic fluid collection surrounding the testis. The usual step is to reassure and monitor, with surgery if it is not relieved after 1-2 years; the Tx is hydrocelectomy. A non-communicating hydrocele in the newborn resolves within 6 months. Any elderly patient with a hydrocele requires US to exclude secondary causes such as tumor, since it may be the presenting feature of testicular cancer. To differentiate a hydrocele from an indirect hernia, place the fingers above the testis. A hydrocele and an epididymal cyst both transilluminate, but the hydrocele is not separated from the testis while the cyst is separated.

Seen whole, a hydrocele is an abnormal collection of serous fluid in some part of the processus vaginalis, and it comes by one of three routes: excessive fluid production, defective fluid absorption by the tunica vaginalis, or interference with lymphatic drainage. A primary hydrocele develops slowly and becomes large and tense, and occurs in people over 40. It is classified by what it connects with. A vaginal hydrocele surrounds the testes in the layer of the tunica vaginalis and does not connect with the peritoneal cavity. A congenital hydrocele is associated with a hernial sac and does connect with the peritoneal cavity. An infantile hydrocele extends from the testes to the deep inguinal ring and does not connect with the peritoneal cavity. A hydrocele of the cord lies along the cord anywhere from the deep inguinal ring to the upper scrotum, and connects with neither the peritoneal cavity nor the tunica vaginalis. A secondary hydrocele is small and lax and belongs to a younger age group, and its causes are infection such as filariasis and mumps, inflammation such as epididymoorchitis, trauma, and tumour.

The examination signs go with that. The testis cannot be palpated separately, which is what distinguishes a hydrocele from an epididymal cyst; one can get above it; it is smooth and well defined; it is fluctuant, the fluid being rich in protein, with albumin, fibrinogen and cholesterol; it transilluminates, though a long standing hydrocele does not, because of fibrin and blood products and a thick wall; it is not reducible; and there is no impulse on coughing.

The examination of a scrotal swelling runs as a scheme of three questions. Can I get above it? If not, it is an inguinal hernia; if so, it is a primary scrotal swelling. Is it cystic? If the testis is not palpable within it, it is a hydrocele; if the testis is felt separate, it is a cyst of epididymis. Is it solid? If it is confined to the testis, it is a tumour, or a gumma, which is rare; if it is the epididymis, it is chronic epididymitis, probably TB or what is left of an acute infection.

Transillumination is what carries the second question, and a swelling that does not transilluminate is not a hydrocele. In a 16 year old boy with a 10 day history of left testicular swelling, where the testis is about twice the size of the normal right testis, feels heavy and does not transilluminate, the best next step is ultrasound of the scrotum: spermatocele and hydrocele are off the list, and what is left is a solid testicular mass, in which neoplasm is the main concern. Warm compresses or antibiotics with reassessment in 1 week would be treating it as an infection, and imaging and lab work come before any percutaneous or open testicular biopsy.