The prostatic utricle is a small, epithelium-lined diverticulum of the prostatic urethra.

Utricle is derived from the Latin word “pouch,” which forms a cul-de-sac. The prostatic utricle (pouch of the prostate) is a small diverticulum (6 mm long) in the prostatic urethra (Fig. 20.1).

It is also known as the vagina masculina or vesicula prostatica.

It is a normal anatomic variant representing the remnant of the fused caudal ends of the Müllerian ducts. This origin is occasionally disputed.

It is considered to represent the male homologue of the female uterus and vagina.

In 1905, Robert William Taylor stated the function of the prostatic utricle thusly: “In coitus it so contracts that it draws upon the openings of the ejaculatory ducts, and thus renders them so patulous that the semen readily passes through.”

Utricle cysts always arise from the level of the verumontanum and are always in the midline.

The cyst typically lies between the bladder and the rectum and, thus, is palpable on per rectal exam in 50 % of the cases.

They are variable in size but are usually small in size (commonly <10 mm). They can however grow to reach a large size.

Morphologically, prostatic utricle cyst appears as a small, single, smooth, unilocular cyst of variable size.

The cyst lining can be:

Prostatic utricle cyst is usually seen during the first to second decades of life, with a mean age range of 26 years.

There is an association between utricular cysts and:

Hypospadias is considered the most commonly associated malformation with the prostatic utricle (14–47 %), and the increasing severity of the hypospadias correlates with increasing size of the utricle (Figs. 20.2 and 20.3).

Normally, the prostatic utricle distends with urine during voiding and then passively drains.

Poor emptying leads to urine retention and stasis and this leads to complications including:

Utricular cyst is rare but along with its rarity, it presents a challenge in its diagnosis and proper management. Awareness of this is important.

Persistence or untreated prostatic cyst could be a cause of infertility.

The differential diagnoses include mullerian duct cysts, bladder diverticulum, cystic teratoma, seminal vesicle cyst, epididymal cyst and Wolffian duct cyst.

Embryologically, in the male fetus the Mullerian ducts regress under the influence of anti-Mullerian hormone (Mullerian inhibiting substance).

This is a glycoprotein secreted by the Sertoli cells of the fetal testes at eight gestational weeks.

Persistence of the Mullerian ducts as result of failure of synthesis or action of Mullerian inhibitory substance results in persistent Mullerian duct syndrome.

This is characterized by the presence of uterine tissue and fallopian tubes in a phenotypic and genotypic male.

Utricular cysts are thought to result from incomplete regression of the Mullerian ducts or incomplete androgen-mediated closure of the urogenital sinus caused by an error in the production or sensitivity to local testosterone or anti-Mullerian hormone.

These cysts are differentiated anatomically from Mullerian duct cysts.