Cowper Duct Syringocele - A Rare Entity

Introduction

The urogenital system consists of the reproductive system and excretory system. The urethra, penis, and prostate gland are important parts of the male urogenital system. Apart from this, numerous accessory glands are present that help in the process of excretion and reproduction. Cowper’s gland is a tiny gland present in the male urogenital tract.

What Is Cowper's Glands?

Cowper’s glands are also known as bulbourethral glands. The name of the gland is named after the surgeon William Cowper. This is an accessory sexual gland that helps in the urethral lubrication process. Also, semen coagulation is regulated by this gland. This gland is situated within the urogenital diaphragm. A deep perennial pouch surrounds these two exocrine glands. Apart from the two main Cowper’s glands, the second pair of accessory glands are situated within the bulbospongiosus tissue. The two main glands are situated superior to the bulb of the penis and posterolateral to the membranous urethra and superior to the bulb of the penis. The ducts of the Cowper’s gland open up into the bulbourethral and into the proximal portion of the spongy urethra. Accessory ducts are also present, which drain into the main duct. The central duct reaches the bulbourethral by piercing the spongiosum.

Development:

Embryologically this gland is developed during the 10th week of intrauterine life. The bulbourethral gland is formed from the pelvic urethra. Several endocrine and procaine signals help in the formation of this gland from the membranous urethra. Dihydrotestosterone (DHT) is one of the key hormones that help in the development of this gland.

Internal Structures:

Cowper's gland is a small multilobulated structure. These lobules are well-demarcated and are made up of tubuloalveolar glands. A thin connective capsule that encloses the tubuloalveolar glands and is made up of columnar epithelium. These glands' radiators from the central excretory duct are lined by pseudostratified epithelium, and it is entrapped within the fascicles of the muscle. Stains like smooth muscle mucin and actin can be used for positive staining of this gland. On the other hand, stains like prostatic acid phosphatase (PAP), S100, and carcinoembryonic antigen (CEA) negatively stain the gland.

Function:

• During sexual excitement, glycoproteins are released by Cowper's glands. This provides lubrication to the semen.

• This secretion helps in the neutralization of acidic pH in the vagina or the acidic pH of urine. Also, the survival of sperm increases with the help of such secretions.

• Such secretion can also be present in the pre-ejaculatory secretion, which helps moisturize and penetrate. Sprem is not present in this secretion. Sexual stimulation or foreplay cause excitement which leads to the secretion of this from the tip of the urethra through Cowper's gland.

• Prostatic acid phosphatase (PAP) and prostatic specific acid phosphatase (PSAP) are two enzymes that Cowper's gland secures.

What Is Cowper's Duct Syringocele?

Cowper’s gland syringocele is uncommon cystic deformation of the male urethra. This is a cystic distention in nature. Such dilations are mainly seen in the main duct of the Cowper’s gland. It is most prevalent in young individuals and in pediatric patients. The clinical types of Cowper’s duct syringocele are:

1. Simple Syringocele: Simple syringocele with modest dilatation of duct.

2. Perforate Syringocele: In this type, a perforated syringocele makes a connection with the patulous urethra.

3. Imperforate Syringocele: Imperforate syringocele with a dilated bulbous duct.

4. Ruptured Syringocele: In this type, syringocele is ruptured and leaves a covering membrane behind. This coving is present in the urethra giving a “ball-on-chain” appearance. This membrane causes obstruction.

Based on building luminal pressures within the ducts, syringocele may follow a standard maturation from simple to imperforate to either perforated or ruptured. According to Bugeja et al., the extent of the intraluminal pressure is the true indicator. This determines the amount of blockage and extent of the dilation. Based on symptomatic and radiological evidence, Campobasso et al. categorized Cowper's duct syringocele into two types. These are; obstructing type with obstructive urinary symptoms and non-obstructing syringocele with various urinary tract complications like urinary tract infection, fever, and haematuria. Bevers et al. divide it into two types on the basis of its opening into the urethra. This can either be open type or closed type.

What Are the Symptoms?

As already discussed, the extent of the severity is based on inter luminal pressure. The increased inter-luminal pressure determines the amount of dilation and symptoms. The clinical manifestations are:

1. Urinary incontinence is one of the prime symptoms in mild cases. In such cases, pt complains of sudden leakage of the urine.

2. The presence of blood is commonly seen in moderate cases.

3. Painful and difficult urination is also observed.

4. Unable to form proper urinary stream and force during urination.

5. Pain in the lower abdominal region.

6. Pain in the perianal region.

7. Less amount of urination and a very small amount of urination because of obstruction.

8. Chronic obstruction leads to inflammation of the kidneys. This causes hydronephrosis or swelling of the kidneys.

9. Vesicoureteral reflux or backflow of urine is seen in children.

10. Scrotal mass or scrotal (infection of the testicles) abscess can also be observed.

11. In severe cases, a perineoscrotal mass or abscess leads to a perineal sinus or fistula (abnormal communication between skin and anas).

What Are the Diagnostic Procedures?

1. In ultrasonography examination, it appears as a unilocular cystic lesion in the posterior and posterolateral aspect of the posterior region of the urethra.

2. Urethrography (radiographic assessment of urethra by using) is contraindicated in this case.

3. Cystourethroscopy and proctoscopy (a procedure to examine the anas and rectum) can directly visualize the cystic enlargement.

4. Other than this, procedures like computed tomography (CT) scans and magnetic resonance imaging (MRI) can be used for examining cystic dilation of the Cowper's duct syringocele.

What Are the Treatment Options?

The treatment options are:

1. Asymptomatic cases can be treated by endoscopic procedures. Transurethral endoscopic unroofing is done in pediatric cases. Marsupialization of the cystic lesion is effective in both open and closed syringocele cases. Holmium: YAG laser is used for laser ablation of cystic lesions. Some asymptomatic cases can be cured without any intervention.

2. Open surgical excision of the cystic mass is indicated in large cases of cystic growth.

Conclusion

Cowper’s gland is a small gland located near the penis. Production of pre-ejaculatory secretions and the coagulation of the semen are the usual functions of this gland. The cystic dilation of the main duct of the Cowper’s gland is known as syrinoele. It is managed by surgical interventions.