see also:

• gynaecology
• ovarian tumours
• the patient with an adnexal mass
• the patient with acute abdominal pain in the ED

• account for 20-50% of ovarian masses in post-menarchal women during the reproductive years
• ruptured cysts may present as acute severe pelvic pain worse on movement +/- rebound tenderness. The pain usually decreases over 1-2 days.
• torsion of the cyst is more likely in larger cysts and will cause prolonged pain unless it spontaneously untwists. Torsion may also cause bleeding or infarction of the ovary.
• those smaller than 6-8cm will usually disappear after 1-2 menstrual cycles, and if still a problem, may shrink or disappear with combined oral contraceptive pill (OCP) Rx.
• those larger than 6-8cm should be referred to O&G as suspicion of neoplasm is increased.
• may be found in prepubertal females.

• occur after ovulation (and thus in early pregnancy) and can reach 6-8cm diameter.
• usually disappear over 1-2 menstrual cycles or with combined oral contraceptive pill (OCP) Rx, or by the end of the 1st trimester of pregnancy.

• small surface cysts that are benign, usually simple cysts, and generally asymptomatic.

• sometimes present in normal pregnancy, but more often accompany trophoblastic disease (30% of these patients have enlarged ovaries)
• multiple cysts ranging from 1-15cm causing ovaries to enlarge rapidly and may continue growing for a short time after delivery of the molar pregnancy then return to normal size within 3-4 months.

• see polycystic ovary syndrome (PCOS) / polyendocrine metabolic ovarian syndrome (PMOS)
• generally smooth, enlarged ovaries on palpation
• USS shows numerous 2-3cm subcapsular cysts
• FSH/LH ratio usually LH elevated several times the normal ratio of 1:1 or 2:1

• chocolate cysts associated with endometriosis
• typically immobile as they form extensive scarring
• gradually enlarge over many months
• pain classically starts 1-2 days prior to menses but may be asymptomatic
• if larger than 2cm, usually require surgical Rx

• remnants of wolffian ducts
• account for 10% of adnexal masses in reproductive years.
• benign cysts are most commonly found in 30-40yr olds but may occur in any age.
• tend to expand within the mesosalpinx, displacing the uterus both out of the pelvis and away from the involved side.
• have no pedicle and thus not at risk of torsion.

• is a pedunculated cyst of mullerian origin, usually 1-2cm and usually of no concern, however, may reach 10-15cm and cause torsion of the adnexa.