Ovarian Cysts and Tumours

An ovarian cyst is a fluid-filled sac within the ovary; the obvious concern of patients with ovarian masses is the presence of malignancy

Aetiology

  • Ovarian masses can be benign, borderline, malignant or metastatic
  • Tumours can arise from any of the 3 cell types in the ovary: surface epithelium (most common), germ cell (more common in women <40 years), sex cord

Risk factors

  • Ovarian cancers are believed to derive from surface epithelial irritation during ovulation
  • Therefore, the more ovulations that take place, the increased risk of developing malignancy:
    • Nulliparity
    • Early menarche/late menopause
    • HRT containing oestrogen only
    • Smoking
    • Obesity
  • There is also a genetic component to ovarian cancer - BRCA1 and 2, Lynch II syndrome

Pathophysiology

Classification of ovarian cysts (benign)

  • No cytological abnormalities, proliferative activity absent or scant
  • No stromal invasion
Non-neoplasic
  • Functional:
    • Follicular cysts: can form when ovulation doesn't occur, follicle doesn't rupture but grows until it becomes a cyst
      • Thin walled, lined with granulosa cells
      • Rarely >5cm diameter
      • Usually resolve spontaneously over a few months
      • May cause menstrual disturbance
      • Consider as differential in acute abdomen as may bleed or rupture
      • Often asymptomatic/incidental finding
    • Corpus luteal cysts: occur in the luteal phase of the menstrual cycle after the normation of the corpus luteum
  • Pathological:
    • Endometrioma (’chocolate cysts’) - the presence of endometrial glands and stroma outside the uterine body
    • Polycystic ovaries
    • Theca lutein cyst - result as a consequence of markedly raised hCG e.g. molar pregnancy, regress upon resolution of the raised hCG
Benign neoplasic
  • Epithelial:
    • Serous cystadenoma
    • Mucinous cystadenoma
    • Brenner tumour: tumour of transitional type epithelium, usually benign, borderline and malignant variants are rare
  • Benign germ cell tumours: mature cystic teratoma (Dermoid cyst)
    • Usually occur in young women, occur frequently in pregnancy
    • As germ cell in origin they can contain teeth, hair, skin and bone
  • Sex-cord stromal tumours:
    • Fibroma: may produce oestrogen causing uterine bleeding
    • Sertoli-Leydig cell tumours: rare sex cord tumours, may produce androgens

Borderline ovarian tumours

  • Cytological abnormalities, proliferative, but with no stromal invasion
  • Growth much more controlled than cancer
  • Unlikely to spread, even if spread tend to implant rather than deeply invasive
  • Usually a better prognosis compared to ovarian cancer

Malignant tumours

  • Stromal invasion
  • Serous carcinoma: two distinct entities with different precursor lesions
    • High grade: serous tubal intraepithelial carcinoma (STIC), most cases are essentially tubal in origin
    • Low grade: serous borderline tumour
  • Endometrioid and clear cell carcinoma: strong association with endometriosis of the ovary
    • Endometroid carcinomas graded the same as uterine tumours
    • Most endometrioid carcinomas are low grade and early stage
    • Association with Lynch syndrome
  • Dermoid cysts can (rarely) become malignant germ cell tumours (somatic malignancy e.g. SCC, thyroid carcinoma)
  • Granulosa cell tumour: a potentially malignant type of sex cord tumour, may be associated with oestrogenic manifestations

Secondary ovarian tumours (metastatic)

  • Most often from breast, pancreas, stomach and GI primaries
  • 'Kruckenberg' tumour - tumour with characteristic signet ring histology which is usually metastatic from stomach
    • Suspect Kruckenberg when the ratio of CA125/CEA is <25

Clinical presentation

  • Clinical features depend on size and type of pathology present
  • Common presentations include:
    • Incidental and symptomatic
    • Chronic pain
    • Acute pain
    • Bleeding per vagina
  • Symptoms suggestive of ovarian malignancy include:
    • Persistent abdominal distension
    • Early satiety and/or loss of appetite
    • Pelvic or abdominal pain
    • Increased urinary urgency and/or frequency
    • Ensure ovarian cancer is tested for in any women 50 years or over who has experienced symptoms within the last 12 months that suggest IBS as IBS rarely presents for the first time in women of this age

Investigations

Urine pregnancy test

  • Rule out pregnancy

Tumour markers

  • CA-125 is a glycoprotein used as a tumour marker - can also be elevated in e.g. ovulation, pregnancy, endometriosis, autoimmune disease, cirrhosis
  • CEA - in adults, CEA may be elevated in malignancies that produce the protein, particularly mucinous cancers associated with the GI tract or ovary
    • CEA can be elevated in other malignancies (breast, pancreas, thyroid, lung) as well as in some benign conditions e.g. cigarette smoking, liver cirrhosis, IBD
    • Suspect metastatic ovarian masses if CA125/CEA <25
  • Other tumour markers in women <40 years: alpha foeto-protein (rasied in embryonal carcinoma), HCG (raised in choriocarcinoma), LDH (raised in dysgerminoma)

Imaging

  • USS
    • Benign features include: unilocular lesion, absence of vascularity
    • Malignant features include: irregular solid tumour, ascites, at least 4 papilary structures, very strong blood flow
  • MRI (premenopausal)
  • CT (postmenopausal)

RMI (risk of malignancy index)

  • Uses menopausal status, USS features and serum CA125 to give a prediction of cancer risk which aids management

Figo staging of ovarian cancer

  • Stages 1-4

Management

Benign ovarian tumours

  • Conservative
  • Medical - GNRH analogues, OCP
  • Surgical - laparascopic/laparotomy
  • Remember acute presentation - torsion, rupture

Borderline ovarian tumours

  • Young women - unilateral cystectomy/oophrectomy with close followup
  • Postmenopausal women - pelvic clearance

Ovarian cancer

  • Stage 1A cancers or fertilility sparing sugery in young women with germ cell tumours - surgery only
  • Early stages - surgery and adjuvant chemotherapy
    • Open hysterectomy, BSO and infracolic omentectomy
  • Advanced stages - neoadjuvant chemotherapy followed by surgery (radical debulking)
  • Surgery is only performed in secondary (metastatic) ovarian tumours if the mass is causing symptoms