It is also seen with torsion of the testis and with some testicular tumors. A secondary hydrocele is usually lax and of moderate size: the underlying testis is palpable. A secondary hydrocele subsides when the primary lesion resolves. Acute/chronic epididymo-orchitis
Torsion of testis
Testicular tumor
Hematocele
Filarial hydrocele
Post herniorrhaphy
Hydrocele of an hernial sac

Infantile hydroceles
It does not occur only in infants but it occurs in adults also, a hydrocele is usually an expression of a patent processus vaginalis (PPV). The tunica and the processus vaginalis are distended to the inguinal ring but there is no connection with the peritoneal cavity. Congenital hydroceles
The processus vaginalis is patent and connects with the general peritoneal cavity. The communication is usually too small to allow herniation of intra-abdominal contents. Digital pressure on the hydrocele does not usually empty it, but the hydrocele fluid may drain into the peritoneal cavity when the child is lying down. Ascites or even ascitic tuberculous peritonitis should be considered if the swellings are bilateral. Encysted hydrocele of the cord
There is a smooth oval swelling near the spermatic cord which is liable to be mistaken for an inguinal hernia. The swelling moves downwards and becomes less mobile if the testis is pulled gently downwards. Rarely, a hydrocele develops in a remnant of the processus vaginalis somewhere along the course of the spermatic cord. This hydrocele also transilluminates, and is known as an encysted hydrocele of the cord. In females, a related region in females, a multicystic hydrocele of the canal of Nuck sometimes presents as a swelling in the groin.
Local infiltration anesthesia is not satisfactory because it cannot abolish abdominal pain due to traction on the spermatic cord. In long standing cases, hydrocele fluid may be opalescent with cholesterol and may contain crystals of tyrosine.After aspiration of a primary hydrocele, fluid reaccumulates over the following months and periodic aspiration or operation is needed. For younger patients, operation is usually preferred. Sclerotherapy is an alternative; after aspiration, 6% aqueous phenol (10-20 ml) together with 1% lidocaine for analgesia can be injected, and this often inhibits reaccumulation. These alternative treatments are generally regarded as unsatisfactory treatment because of the high incidence of recurrences and the frequent necessity for repetition of the procedure. References
External links

Hydrocele at eMedicine