Vulvar endometriomas are rare, painful cysts that result from extrauterine implantation of functioning endometrial tissue (endometriosis—see Endometriosis).

Rarely, endometriosis occurs in the vulva (or the vagina), sometimes producing cysts (endometriomas), often at the site of previous surgery (eg, episiotomy).

Endometriomas usually develop in the midline. They may be painful, particularly during intercourse. During menstruation, pain increases and endometriomas may enlarge. Endometriomas are tender and may appear blue. They can rupture, causing severe pain.

Diagnosis is by physical examination and biopsy. Treatment involves excisional biopsy.

Last full review/revision December 2008 by S. Gene McNeeley, MD