Lectures in Obstetrics, Gynaecology and Women’s Health

12. Ovarian Cysts

Gab Kovacs¹ and Paula Briggs²

(1)

Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia

(2)

Sexual and Reproductive Health, Southport and Ormskirk Hospital, Southport, UK

Definition

Incidence

Aetilogy and Pathogenesis

Clinical Assessment

History

Examination

Investigations

Treatment

Medical

Surgical

Complications

Prognosis

Definition

Every woman who ovulates makes a “cyst” every month – a follicle that usually ruptures and then disappears. Cysts can be physiological (functioning cysts) or pathological (benign or malignant).

Incidence

Ovarian cysts are a common reason for gynaecological referral.

· The use of CHC will limit folliculogenesis and inhibit ovulation, thus significantly reducing the incidence of functional cysts.

Aetilogy and Pathogenesis

The simplest functional cysts are either follicular cysts or luteal cysts. Follicular cysts occur where the developing follicle does not rupture and grows beyond 3 cm. Luteal cysts arise when the corpus luteum becomes cystic. Functional cysts are more common at menarche and in the menopause transition, in the users of progestogen only contraception or in the presence of gestational trophoblast disease. They are classified by the cells from which they originate (Table 12.1).

Table 12.1

Pathological classification of ovarian tumours

Clinical Assessment

History

Many ovarian cysts are asymptomatic and are diagnosed as an incidental finding on ultrasound examination.

· They may cause pelvic pain.

· They may present due to one of the complications – see below (some of which present as an “acute abdomen”).

· The woman may complain of abdominal bloating.

Examination

A pelvic mass may be palpated on abdominal/ vaginal examination.

Investigations

Imaging: An ultrasound examination is the most accurate way of diagnosing ovarian cysts. If the cyst contains solid areas, there is an increase in the risk of malignancy. The pattern of blood flow on Doppler can be helpful with regards to the probability of malignancy.

· CT or MRI can be used to assess ovarian cysts for potential malignancy.

Tumour markers – CA-125 is particularly useful, especially post menopause. It can also be moderately elevated in endometriosis, PID, pancreatitis and cirrhosis of the liver.

Treatment

Medical

· The treatment of physiological cysts is watchful expectancy, unless they cause complications.

· Hormonal – The use of CHC can prevent the formation of functional cysts.

Surgical

· Minor – The cysts could be aspirated with cytological examination of the fluid obtained. They often recur.

Laparoscopic ovarian cystectomy

· Cysts should be removed unruptured.

· Major – If the cysts are large, or malignancy is suspected, laparotomy may be the preferred approach.

Complications

These can be remembered by the acronym “THIN RIM” See Table 12.2.

Table 12.2

Acronym for the complications of ovarian cysts

Prognosis

Benign ovarian cysts may cause symptoms because of their size or due to a complication. Whilst some have a malignant potential, most have no long term implications. However, surveillance usually by repeat ultrasound examination until resolution is recommended.