For unknown reasons, patches of tissue from the lining of the uterus (endometrial tissue) sometimes appear outside the uterus. This disorder is called endometriosis. Endometriosis rarely occurs in the vulva (the area that contains the external genital organs). It is more common in other locations, such as the ovaries.
Sometimes the endometrial tissue forms a cyst (endometrioma).
Endometriomas often develop at the site of a previous operation, such as an episiotomy (an incision to widen the opening of the vagina to help with delivery of a baby) or repair of a tear in the vagina or vulva that occurred during delivery.
Endometriomas may be painful, particularly during sexual intercourse. Endometriomas respond to hormones just as normal endometrial tissue does. Thus, they can enlarge and cause pain, particularly before and during menstrual periods. Endometriomas are tender and may look blue. They can rupture, causing severe pain.
During a pelvic examination, doctors can usually see or feel endometriomas that cause symptoms.
Endometriomas in the vulva are surgically removed. This procedure is usually done in an operating room but may be done in a doctor’s office. A local anesthetic is used.
Doctors do a biopsy of the removed tissue to make sure it is not a melanoma (a skin cancer), which can occur on the vulva and vagina.