It is the most common benign tumor of the vagina. Normally, the vagina does not have glands, but occasionally isolated ectopic crypts may be found, which can form retention cysts containing fluid. These are not neoplastic or hyperplastic tumors. Generally, the cyst epithelium often originates from the Müllerian duct, mesonephric duct, and urogenital sinus during the embryonic period. The cyst of the Gartner's duct is derived from the remnants of the Wolffian duct.

bubble_chart Clinical Manifestations

The cyst may be segmented or multiple, with varying sizes, generally 2–3 cm in diameter. The surface is smooth, fixed, and has a cystic sensation upon palpation. These cysts are often small and clinically insignificant, but occasionally they can grow large enough to cause dyspareunia or pain during intercourse, or even obstruct childbirth. Sometimes, they may compress the bladder trigone, leading to increased frequency of urination. In rare cases, their slender, cord-like pedicles may cause intestinal torsion and obstruction.

The contents of the cyst are mostly watery, serous, or milky fluid, though some may appear dark brown. The color and viscosity vary depending on the presence and extent of intracystic hemorrhage.

bubble_chart Diagnosis

Small cysts located on the anterior or lateral walls of the vagina are not difficult to diagnose. Larger cysts protruding at the vaginal orifice or between the labia may resemble bladder prolapse, but they do not shrink after urination. Alternatively, when a metal catheter is inserted while simultaneously pressing the base of the cyst with a finger, the distance between the catheter and the cyst can be felt, making differentiation straightforward. Cysts located in the posterior vaginal fornix should be distinguished from uterorectal fossa hernias. The latter often enlarge during coughing or shrink—or even disappear—when pushed upward with a finger. Additionally, during a rectovaginal-abdominal examination, if the patient bears down, a bulging sensation may be felt in the rectovaginal septum, caused by intestinal loops entering the hernia sac of the uterorectal fossa due to increased abdominal pressure. Vaginal cysts do not exhibit these changes. Cysts located in the lower half of the external genitalia wall must be differentiated from urethral diverticula and abscesses of the urethral glands. Although the latter two also cause vaginal bulging, they communicate with the urethra. When pressed forward, urine or pus may discharge from the urethra. Small cysts near the hymen on the posterior vaginal wall are often inclusion cysts. Additionally, differentiation is required from rare conditions such as double uterus, double vagina malformations, or unilateral vaginal atresia with retained menstrual blood. Although these patients menstruate, dysmenorrhea progressively worsens, and the unilateral vaginal cyst becomes tense and purplish. If necessary, local aspiration can aid in diagnosis.

The primary treatment is surgical excision. If the cyst is not located too high, the surgery is usually not difficult, but care must be taken during the dissection to avoid injuring the urethra or bladder. If the tumor is large and located deep in the fornix, extending into the broad ligament, it may be impossible to completely remove it via the vagina, even with concurrent abdominal surgery, which is also very challenging. Some authors suggest that after scraping the residual cyst wall with a curette, the edges of the remnant can be sutured to the corresponding edges of the vaginal mucosal incision to create an opening. The vagina can then be packed with gauze to compress the residual cyst cavity, potentially allowing the remaining cyst wall to adhere and close completely. Even if complete adhesion does not occur, the residual cyst is unlikely to re-expand.