A hydrocele is an accumulation of serous ﬂuid greater in amount than the amount normally present between the parietal and visceral testis tunica vaginalis layers. As the testis descends (see Plate 3-5) from the retroperitoneum to the scrotum, it carries with it two layers of peritoneum. Abnormalities of these coverings and of the processus vaginalis communicating with the peritoneal cavity may lead to several kinds of hydrocele. The most common type is simple hydrocele, in which the normally formed tunica vaginalis is distended with ﬂuid. In infantile hydrocele, the ﬁngerlike processus vaginalis fails to close and extends upward to the upper scrotum or inguinal canal but does not communicate with the peritoneal cavity. In congenital or communicating hydrocele, with or without hernia, a lumen in the processus vaginalis permits communication with the abdominal cavity, so that bowel and peritoneal ﬂuid may extend to the scrotum and hydrocele ﬂuid may reach the peritoneal cavity. Congenital hydrocele may or may not be associated with descent of the bowel and inguinal hernia.
Hydrocele of the cord occurs as a localized collection of ﬂuid in an encysted sac of peritoneum within the spermatic cord. It does not communicate with either the tunica vaginalis space below or the peritoneum above. Hernial hydrocele (not illustrated) is an accumulation of ﬂuid within the tunica vaginalis as a result of a limited projection of the processus vaginalis from the peritoneal cavity inferiorly into the scrotum. However, the hernia pouch terminates before reaching the tunica vaginalis and does not communicate with it. Usually, neither bowel nor omentum is present in the sac, and the hydrocele ﬂuid in the sac can be pressed back into the peritoneum. Rare types of localized hydroceles can also occur, involving either a portion of the epididymis or the testis. Acute hydrocele is usually secondary to trauma, tumors, or underlying infection of the testicle or epididymis. Chronic hydrocele may be the end result of the acute form, but in many cases no history of an acute phase exists, nor are underlying diseases found, in which case it is termed idiopathic hydrocele. Hydroceles can follow trauma and occur after inguinal herniorrhaphy, varicocele ligation, or other retroperitoneal surgery that blocks lymphatic ﬂow through the spermatic cord.
Hydrocele ﬂuid is generally straw-colored and odorless and resembles serum. In acute cases, the ﬂuid may be ﬁbrinous, bloody, or even purulent. The parietal layer of the tunica vaginalis is usually thin, but it may become thickened and even calciﬁed in chronic cases. Hydroceles are generally situated anterior to the testicle, which it displaces posteriorly in the scrotal cavity. Hydroceles should be differentiated from hernia, testicle tumors, hematocele, and spermatocele. Transillumination of the scrotum should reveal a “glowing” ﬂuid sac with hydrocele. Aspiration of the hydrocele ﬂuid for cytologic or chemical assessment should only be performed when coexistence of hernia has been excluded. The treatment is watchful waiting, repeated needle aspirations (as the ﬂuid recurs quickly), or operative excision of the parietal tunica vaginalis. Aspiration followed by injection of sclerosing solutions is not as effective as tunica vaginalis excision. In long-standing hydroceles in which the tunica has become thick, some degree of testicular atrophy may result from chronic pressure.
A spermatocele is an intrascrotal cystic mass resulting from partial obstruction or diverticula of the efferent ductule system near the caput epididymis (see Plate 3-3). When small, they can be confused with epididymal cysts (which generally remain small) and appendices of the testis and epididymis, but these latter structures do not contain sperm, unlike spermatoceles. The cyst is lined by pseudostratiﬁed epithelium and contains turbid, milky ﬂuid, with immotile sperm and lipid granules. On palpation, spermatoceles appear as a round mass distinct from the testis, with a narrower “waist” between the testis and the cyst attached to it. Spermatoceles are located within the tunica vaginalis space, but an extra-vaginal variety can occur that lies posterior to the testis. Spermatocele and hydrocele can occur concomitantly, in which case the former remains unrecognized unless the ﬂuid is observed on aspiration. Most spermatoceles are asymptomatic, except for a slight dragging sensation in the scrotum due to a “mass effect.” Spermatoceles tend to become symptomatic when they enlarge to the size of a normal 20-mL testis. Excision is the treatment of choice and should be only judiciously considered in reproductive-age men, as scarring in the epididymal bed of the excised lesion could obstruct the remaining efferent ducts and lead to duct obstruction and infertility.