Case notes

In July 2008, a 33-year-old woman, para 2, attended the outpatient department for evaluation of a vaginal mass that extended 2 cm beyond the hymen. The mass was accidentally discovered 4 weeks earlier when she gave birth vaginally to a healthy baby at a gestational age of 39 weeks. Her medical history was unremarkable, and she took no medication.

Conclusion

Examination revealed a large (7 × 3 cm) Gartner duct cyst in the right anterolateral wall of the vagina ( Figure 1 ). Magnetic resonance imaging (MRI) showed no relationship between the cyst and the bladder or the ureter ( Figure 2 ).

Mass discovered in right anterolateral wall of vagina. Cervix ( triangles ); urethral catheter ( arrows ).

Kruse. A chance finding. Am J Obstet Gynecol 2010.

Magnetic resonance imaging showed no relationship between cyst ( triangles ) and bladder ( arrows ) or ureter.

Kruse. A chance finding. Am J Obstet Gynecol 2010.

Vaginal cysts are present in about 1% of women. They can be functionally classified as squamous inclusion cysts, mesonephric (Gartner duct) cysts, müllerian cysts, or Bartholin gland cysts. The prevalence of Gartner duct cysts is approximately 0.05%. Most are small, are asymptomatic, and require no treatment. On histology, they are lined by low cuboidal non-mucin-secreting cells whose cytoplasmic material does not stain positive with mucicarmine or periodic acid–Schiff reagent.

The urogenital system develops from the intermediate mesoderm, which forms the urogenital ridge and mesonephric ducts. In turn, the mesonephric ducts give rise to the definitive ureters, trigone, and bladder neck. Although the distal mesonephric ducts are ordinarily absorbed in the female, they can persist as vestigial remnants–or Gartner duct cysts–in the anterolateral wall of the vagina. It is assumed that these cysts result from secretion by small, isolated, epithelial remnants after incomplete regression. Typically, Gartner duct cysts have an average diameter of 2 cm, but they can become quite large, as was the case in our patient. They may extend cranially through the entire length of the vagina and via the cervix, into the broad ligament, following the route of the mesonephric duct.

Congenital malformations of the genital tract are frequently associated with urinary tract abnormalities, because interaction between the 2 ductal systems is necessary for normal growth, as described above. Cases of ectopic ureter, unilateral renal agenesis, and renal hypoplasia have been reported in association with Gartner duct cysts. The finding of an anomaly in 1 system should alert the clinician to the possibility of an abnormality in the other. Awareness of this association should then prompt the clinician to image the urinary tract when evaluating patients with Gartner duct cysts.

MRI, with its high-contrast resolution and multiplanar capabilities, is very useful for this purpose, providing excellent visualization of the vagina and surrounding tissue. Gartner duct cysts usually exhibit low T1 and high T2 signal intensity. On the other hand, computed tomography and pelvic sonography provide little information about abnormalities that are in continuity with the vagina.

This case illustrates the usefulness of MRI in assessing the characteristics of a large Gartner duct cyst that warranted excision and in determining its exact location relative to the bladder and ureter. The patient underwent surgery, experiencing an uncomplicated recovery. At a 6-week follow-up visit, she was in good clinical condition.