William Cowper (1666–1709) was an English surgeon and anatomist, who described, for the first time, in details the bulbourethral glands which acquired latter on his name.

The term syringocele was firstly used by Fenwick, in 1896 [1], and the first classification reported by Maizel et al. in 1983 [2].

The true prevalence of Cowper’s syringocele is unknown, it is thought to be more pronounced in the pediatric population, perhaps because symptoms are appreciated preferentially at a younger age. However, there is a growing body of literature suggesting the problem exists notably in the adult population as well [1]. It was reported at a rate of about 1.5 % in pediatric cystourethrography and of 2.3 % in autopsic studies [3]. Moormann reported 169 cases of syringoceles as an incidental findings during evaluation for impotence [4].

Cowper’s glands are composed of two exocrine structures located in the deep perineal pouch between fascial layers of the urogenital diaphragm, The glands eventually form two collecting ducts that measure on average 2.5 cm each, which open in the bulbar urethra distal to the prostatic ducts openings (Fig. 31.1).

Although anatomic variations exist, the majority of ducts combine to make one confluent passage that opens at the posterior aspect of the bulbous urethra. They are homologous to Bartholin’s glands in females.

The etiology of syringocele is not clear, both congenital and acquired types are described. Stasis and pressure changes may cause obstruction to the orifices of the bulbourethral ducts resulting in accumulation of mucous and/or urine causing glandular cystic dilatation. It may then lead to bacterial colonization and secondary infection, but the genesis of congenital Cowper’s syringocele is not completely clear, as syringocele appears to develop in a variety of environments across different species. The literature search has provided some clues to the future directions in understanding the aetiology of syringocele, which include genetic mutations that affect stromal-epithelial interactions with or without the effects of disturbances in hormone balance and amino acid transporting pathways [5].

Anterior urethral diverticulum and syringocele of the Cowper’s duct are two different pathologies of the male urethra, but confusion between both conditions is not uncommon, as the syringocele may erode into the bulbous urethra, either spontaneously or after surgery, leading to filling of the cyst during voiding and a resulting in a diverticulum (Chap. 29).

Cowper’s syringocele has been divided into four types by Maizel et al. [2] :