Ovarian cysts

• Benign ovarian tumours are extremely common particularly in young patients

  An ovarian cyst is a fluid filled sac within the ovary
• Most ovarian cysts are asymptomatic. Cysts are often found incidentally on pelvic ultrasound scans. 

  Occasionally, ovarian cysts can cause vague symptoms of:

  • Pelvic pain
  • Bloating
  • Fullness in the abdomen
  • A palpable pelvic mass (particularly with very large cysts such as mucinous cystadenomas)

  Ovarian cysts may present with acute pelvic pain if there is ovarian torsion, haemorrhage or rupture of the cyst.
• Larger cysts >5cm are more likely to result in torsion
• Ovarian tumours can be divided into non-neoplastic (no malignant potential) and neoplastic (ability to turn malignant).

  • A simple ovarian cyst is one that contains fluid only.
  • A complex ovarian cyst can be irregular and can contain solid material,  blood or have septations or vascularity.
• Functional cysts:

  • Follicular cysts - represent the developing follicle - harmless and tend to disappear after a few menstrual cycles
  • Corpus luteum cysts - when the corpus luteum fails to break down and fills with fluid. May cause pelvic discomfort, pain or delayed menstruation. Often seen in early pregnancy
• Other types of ovarian cysts:

  • Serous cystadenoma - most common malignant ovarian tumour
  • Mucinous cystadenoma
  • Endometrioma (occurs in endometriosis) - chocolate cyst
  • Dermoid cysts/germ cell tumours - type of teratomas, particularly associated with ovarian torsion
  • Sex cord-stromal tumours
• Take a detailed history and examination for features that may suggest malignancy:

  • Abdominal bloating
  • Reduce appetite
  • Early satiety 
  • Weight loss
  • Urinary symptoms
  • Pain
  • Ascites
  • Lymphadenopathy
• Assess for risk factors for ovarian malignancy:

  • Age
  • Postmenopause
  • Increased number of ovulations
  • Obesity
  • Hormone replacement therapy
  • Smoking
  • Breastfeeding (protective)
  • Family history and BRCA1 and BRCA2 genes
• Premenopausal women with a simple ovarian cyst less than 5cm on ultrasound do not need further investigations.
• Blood tests for postmenopausal women or complex cysts:

  • CA125 tumour marker for ovarian cancer
  • Calculate risk of malignancy index
  • Women under 40 with a complex ovarian mass require tumour markers for possible germ cell tumour - LDH, alpha-fetoprotein and human chorionic gonadotropin (HCG)
• CA125 is a tumour marker for epithelial cell ovarian cancer. It is not very specific, and there are many non-malignant causes of a raised CA125:

  • Endometriosis
  • Fibroids
  • Adenomyosis
  • Pelvic infection
  • Liver disease
  • Pregnancy
• The risk of malignancy index (RMI) estimates the risk of an ovarian mass being malignant, taking account of three things:

  • Menopausal status
  • Ultrasound findings
  • CA125 level
• Possible ovarian cancer (complex cysts or raised CA125) requires a two-week wait referral to a gynaecological oncology specialist.
• Possible dermoid cysts require referral to a gynaecologist for further investigation and consideration of surgery.
• Simple ovarian cysts in premenopausal women can be managed based on their size:

  • Less than 5cm cysts will almost always resolve within three cycles. They do not require a follow-up scan. 
  • 5cm to 7cm: Require routine referral to gynaecology and yearly ultrasound monitoring.
  • More than 7cm: Consider an MRI scan or surgical evaluation as they can be difficult to characterise with ultrasound. 
• Cysts in postmenopausal women generally require correlation with the CA125 result and referral to a gynaecologist. When there is a raised CA125, this should be a two-week wait suspected cancer referral. Simple cysts under 5cm with a normal CA125 may be monitored with an ultrasound every 4 – 6 months.
• Persistent or enlarging cysts may require surgical intervention (usually with laparoscopy). Surgery may involve removing the cyst (ovarian cystectomy), possibly along with the affected ovary (oophorectomy).
• Consider complications when patients present with acute onset pain. The main complications are:

  • Torsion
  • Haemorrhage into the cyst
  • Rupture, with bleeding into the peritoneum
• Meig’s syndrome involves a triad of:

  • Ovarian fibroma (a type of benign ovarian tumour)
  • Pleural effusion
  • Ascites

  Meig’s syndrome typically occurs in older women. Removal of the tumour results in complete resolution of the effusion and ascites.