A 25-year-old woman has experienced discomfort during sexual intercourse for the past month. On physical examination, there are no lesions of the external genitalia. Pelvic examination shows a focal area of swelling on the left posterolateral inner labium that is very tender on palpation. A 3-cm cystic lesion filled with purulent exudate is excised. In which of the following structures is this lesion most likely to develop?

Bartholin glands may become obstructed, inflamed, and cystic because of abscess formation, which then produces focal pain. A Gartner duct cyst may form in the lateral vaginal wall from the remnant of a wolffian (mesonephric) duct; the cyst is filled with fluid and is usually not inflamed. Hair follicles are not present at the inner labia. The Bartholin gland lies just inferior to the fascia of the urogenital diaphragm and just anterior to the vestibular bulb, which is not glandular and does not become cystic.