Overview

• Cyst → fluid-filled sac.
• Functional Ovarian Cysts → related to fluctuating hormones of the menstrual cycle. Very common in premenopausal women.
  • Follicular Cysts → commonest type of ovarian cyst. Due to non-rupture of the dominant follicle. Tend to disappear after a few menstrual cycles. Lined by granulosa cells.
  • Corpus Luteum Cysts → corpus luteum fails to break down and fills with fluid. Lined by luteal cells. May rupture at the end of menstrual cycle. Normal in early pregnancy.
  • Theca Lutein → associated with pregnancy (grow in response to bHCG).
• Other Ovarian Cysts ⇒
  • Benign Germ Cell Tumour
    • Dermoid Cyst / Mature Cystic Teratoma → most common benign ovarian tumour in those <30. Teratomas (ie. come from germ cells). Rokitansky protuberances (multiple or single white shiny masses that protrude out). Associated with ovarian torsion.
      • May contain hair or teeth.
  • Benign Epithelial Tumour
    • Serous Cystadenoma → benign tumours of epithelial cells (most common epithelial cell tumour). Psammoma bodies.
    • Mucinous Cystadenoma → benign tumours of epithelial cells that can become huge. If ruptures may cause pseudomyxoma peritonei.
  • Endometrioma → lumps of endometrial tissue within the ovary. USS: ground-glass echoes.
  • Sex Cord-Stromal Tumours → arise from stroma (connective tissue) or sex cords. Can be benign or malignant.

Making Diagnosis

Clinical Features

• Most are asymptomatic.
• Pelvic pain, bloating, fullness in abdomen, palpable pelvic mass.
• Acute pelvic pain → if ovarian torsion, haemorrhage or rupture of the cyst.
  • Rupture → sudden onset unilateral pelvic pain precipitated by intercourse or strenuous activity. USS may show free fluid in pelvic cavity.

Investigations

• Risk of Malignancy Index (RMI) → estimates risk of ovarian mass being malignant. Menopausal status + Ultrasound findings + CA125 level.

  • 200 = high risk.

• Germ Cell Tumours Markers → LDH, aFP, HCG.
• Premenopausal + simple ovarian cyst <5cm on ultrasound → no further investigation.

Management Plan

• Premenopausal:
  • Simple/Unilocular Cyst
    • <5cm (NO F/U) → will resolve within 3 cycles. Do not require follow-up.
    • 5-7cm (YEARLY USS) → routine referral to gynaecology and yearly ultrasound monitoring.
    • >7cm (MRI + SURGERY) → further imaging (MRI scan) or surgical intervention.
  • Recurrent / Sustained >5cm / Suspicious / Multiloculated → surgical (laparoscopic cystectomy).
    • Complex (i.e. multi-loculated) ovarian cysts should be biopsied to exclude malignancy.
• Postmenopausal:
  • Suspicious for malignancy therefore should undergo RMI (menopausal status + ultrasound findings + CA125).
    • RMI >200 (increased risk) → CTAP Scan + Gynae Oncology MDT Referral → Laparotomy.
    • RMI <200 (low risk):
      • Asymptomatic, simple cyst, <5cm, unilocular, unilateral → conservative management. Repeat RMI (USS + CA125) in 4-6 months.
      • Symptomatic, non-simple features, >5cm, multilocular, bilateral → consider surgery (bilateral salpingo-oopherectomy).
  • All pre-menopausal women with complex ovarian cysts (RCOG) → serum CA-125, aFP, bHCG. Then can perform elective cystectomy (preferred to aspiration).
  • Requires gynae oncology + laparotomy.