Many Bartholin's gland cysts don't cause any symptoms. They usually are discovered when a woman notices a small, painless mass just outside the opening to the vagina, or when a physician notices it during a routine pelvic examination. However, if the cyst grows larger than 1 inch in diameter, it can cause discomfort when sitting, or during intercourse. If a cyst becomes infected, it fills with pus, and becomes firm, swollen, and very painful, making it difficult for a woman to sit, walk or have intercourse. The pus-filled cyst is called an abscess.