Benign Ovarian Disease


  • Common- occur in around 30% of females (lifetime) with regular menses and 50% with irregular menses
  • Ovarian tumours/cysts can be divided into three groups
    • Physiological (functional) cysts
    • Benign pathological tumours
    • Malignant pathological tumours
  • Only about 6% of ovarian disease will be malignant.  The majority will be benign cysts (70%) and the remainder will be functional (24%)
    • Functional cysts are very common in children/adolescents during development

Types of disease/ Aetiology

  • Functional Cysts
    • Often asymptomatic and found in younger women
    • Follicular cysts
      • Results from either a non-rupture of the dominant follicle during the normal ovarian cycle or a failure of atresia of a non-dominant follicle
      • Small cysts may resolve spontaneously but others are typically larger than 2.5cm and present with pelvic discomfort and heaviness
    • Luteal cysts
      • Results from a failure of corpus luteum dissolution, causing a cyst to form (defined as >3cm)
      • Less common, but more likely to present with intra-peritoneal bleeding following rupture
    • Theca-lutein cysts
      • Caused by luteinisation and hypertrophy of the theca cell layer in response to excessive stimulation from βHCG e.g. in a molar pregnancy, multiple pregnancy, or with iatrogenic ovarian stimulation
      • Less common again but usually bilateral and can result in massive ovarian enlargement
  • Benign epithelial tumours (majority)
    • Serous cystadenoma
      • Most common (particularly ages 40-45). Bilateral in 10-15% of cases and can be malignant in up to 20%
      • Contain thin serous fluid, usually within a unilocular cavity, although they can develop papillary growths which may appear as solid within the cyst space
    • Mucinous cystadenoma
      • More often seen in younger women (20-40).  Normally unilateral (95%) and only 5% will be malignant
      • Larger (can be massive and can rupture), multilocular and filled with thick mucinous fluid.
    • Other types include endometroid cystadenomas (uncommon but possible to be benign- most malignant) and Brenner’s tumour (rare, usually benign uro-epithelial cell tumour)
  • Benign Germ cell tumours (more common in young women)
    • Mature cystic teratoma (Dermoid cyst)
      • Mean age of diagnosis is 30; ~10-20% are bilateral
      • Can undergo torsion and rarely rupture
  • Benign Sex Cord Stromal tumours
    • Theca cell tumour (Thecoma)
      • More common in older women and commonly secrete oestrogen and thus have hormonal effects
    • Fibroma
      • Rare.  Can be associated with Meig’s syndrome of fibroma, ascites and pleural effusions.


  • Majority of patients are asymptomatic and the diagnosis is made by chance after imaging or bimanual examination
  • Pain/Ache in the pelvis/lower abdomen
    • Usually mild-moderate and dull but can be severe and cramping/stabbing if a cyst has torted, ruptured, haemorrhaged or become infected
      • Patients may also be feverish and have a SIRS response
      • If torsion, the pain can be intermittent as the cyst twists on its axis
    • Dypareunia may also be present
  • An abdominal swelling/mass may be present
    • this may cause bloating and may be having pressure effects on the bowel/bladder
      • e.g. urinary frequency, tenesmus, difficulty passing stool
  • Ascites, nausea/vomiting, lethargy etc suggests malignancy
  • There may also be symptoms/signs related to excess hormonal release (rare) e.g. irregular/abnormal menstrual bleeding, post-menopausal bleeding


  • Blood tests
    • FBC +CRP- Infection, haemorrhage
  • Endocervical swabs/High vaginal swabs to rule out PID
  • Urine pregnancy test
  • Pelvic/Transvaginal USS +/- FNA
  • Tumour markers
    • CA125
    • In women <40 with a complex ovarian mass on imaging, β-HCG and alpha fetoprotein should be measured (germ cell tumours)

Risk of malignancy Index (RMI)

  • RMI = U × M × CA125
    • U – (1 point for each of the following; U score is 0 if 0, 1 if 1 and 3 if 2-5)
      • Multilocular cysts, solid areas, metastases, ascites, bilateral lesions
    • M – (1 if premenopausal and 3 if postmenopausal)
    • CA125 in IU/ml
  • If RMI ≥ 250, refer to gynaecology for further investigation (suspicious of malignancy)


  • With small (<5cm) asymptomatic cysts, most can be managed conservatively
    • If they are not growing at a follow-up, then further follow-up is not needed, as they will most likely resolve spontaneously
  • Medium-sized (5-7cm) or growing cysts should be monitored for growth.
  • Persistent larger cysts (>5cm), especially if symptomatic or if they have a complex appearance on USS, should be considered for surgical removal (laparoscopic)
  • Torsion, ruptured and haemorrhaged cysts should be managed surgically urgently (either removal (salpingo-oophrectomy) or untwisting and ovarian fixing (oophoropexy))

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