Ovarian tumours

Ovarian tumours are relatively common and account for ≈ 6 % of  female malignancies. This article tends to focus on the general classification of all ovarian tumours. For specific features : refer to sub articles.

Sub types

Primary ovarian tumours

Epithelial ovarian tumours : ~ 60 - 70 %

• ovarian serous tumours : 
  • ovarian serous cystadenoma : ~ 60 % of serous tumours  
  • ovarian borderline serous cystadenoma :  ~ 15 % of serous tumours
  • ovarian serous cystadenocarcinoma : ~ 25 % of serous tumours - commonest malignant ovarian tumour
• ovarian mucinous tumours : ~ 20 % of all ovarian tumours ¹¹
  • ovarian mucinous cystadenoma : ~ 80 % of mucinous tumours
  • ovarian bordeline mucinous cystadenoma : ~ 10 - 15 % of mucinous tumours
  • ovarian mucinous cystadenocarcinoma : ~ 5 - 10 % of mucinous tumours
• ovarian endometrioid tumour : 8 -15 % of all ovarian tumours
• ovarian cystadenofibroma * / ovarian adenofibroma : can be serous, mucinous, endometrioid, clear cell or mixed
• ovarian cystadenocarcinofibroma : extremely rare
• clear cell ovarian carcinoma : ~ 5 % of ovarian cancer
• Brenner tumour : ~ 2 -3 % of ovarian epithelial neoplasms
• undifferentiated carcinoma of the ovary : ~ 4 % of all ovarian tumours
• squamous cell carcinoma of the ovary

* : sometimes classified as a seperate category rather than under epithelial ⁷

Germ cell ovarian tumours : ~ 20 %

• ovarian teratoma : commonest primary benign tumour of ovary
  • mature ovarian teratoma
  • immature ovarian teratoma
  • specialised teratomas of the ovary
    • struma ovarii tumour
    • ovarian carcinoid tumours
• ovarian dysgerminoma 
• ovarian yolk sac tumour - endodermal sinus tumour
• malignant mixed germ cell tumour of the ovary
• ovarian choriocarcinoma :  < 1 % of ovarian tumours
  • pure primary ovarian choriocarcinoma : extremely rare ²

Sex cord - stromal ovarian tumours : ~ 8 - 10 %

• ovarian fibrothecoma : ~ 5 % of ovarian tumours
  • ovarian fibroma : ~ 4 % of ovarian tumours
  • ovarian thecoma : ~ 1 % of ovarian tumours
• sclerosing stromal tumour of the ovary : rare ⁹
• ovarian Sertoli-Leydig cell tumour - ovarian androblastoma : ~ 0.5 % of ovarian tumours
• granulosa cell tumour of ovary : commonest malignant sex cord tumour
  • juvenile granulosa cell tumour of ovary
  • adult granulosa cell tumour of ovary

Mixed : uncommon

• collision tumours of the ovary :
• ovarian carcinosarcoma : < 1 % 

Other

• ovarian lymphoma
  • primary ovarian lymphoma
  • secondary involvement of the ovary with lymphoma
• metastases to the ovary
  • Krukenburg tumour
  • other metastastic lesions to ovary

General pathology

Serological tests

• CA-125 levels * : elevated in most ovarian malignancies ( ~ 80% in general) : some mucinous and germ cell tumours may not secrete this marker
• AFP levels * : elevated particularly with immature ovarian teratomas ( ~ 50% of cases) and ovarian yolk sac tumours

Risk factors

General risk factors include

• multiparity
• early menopause
• family history (e.g BRCA1 and BRCA2 mutations : particularly for serous types) : contribute to 10% of cases overall
• smoking - especially for mucinous adenocarcinoma
• previous history of breast, endometrial or colon cancer.
• certain ethnic groups

Protective factors

• oral contraceptives
• breastfeeding (this is controversial)

Staging

The FIGO staging system is used for almost all of ovarian cancer : see > ovarian cancer staging