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neo_ovarian

ovarian tumours

introduction

  • ovarian tumours occur in all stages of a woman's life, from childhood, when they are mostly disgerminomas, through the reproductive age, when functional cysts predominate, to menopause when up to 30% of all ovarian tumours are borderline or malignant.
  • malignant ovarian tumours constitute approx. 8% of all ovarian tumours & can be diagnosed as probably malignant pre-operatively in ~80% of cases
  • most ovarian carcinomas are composed of cells that resemble those derived from mullerian ducts. In most ovaries, there are no cells of mullerian origin.
  • recent theories suggest that most high-grade serous carcinomas may actually arise from the fallopian tube epithelial cells, while endometriosis may be a precursor to clear-cell and endometrioid carcinomas as these are derived from ectopic uterine epithelium 1).
  • once these tumours become symptomatic, it would seem early presentation within 1 month vs 6 months does not affect staging or prognosis2)

risk factors for ovarian cancer

  • family history:
    • family history is the strongest risk factor for ovarian cancer. Compared with a 1.6% lifetime risk for developing ovarian cancer in the general population, women with one first-degree relative with ovarian cancer have a 5% risk, and women with two first-degree relatives have a 7% risk.
    • familial clustering of ovarian cancer tends to fall into one of three groups:
      • family history of ovarian cancer only (site specific)
      • family history of breast and/or ovarian cancer (breast/ovarian cancer)
      • family history of nonpolyposis colorectal, endometrial, urologic, prostate, lung, and ovarian cancers (Lynch II syndrome).
        • accounts for 10% of hereditary ovarian cancers
        • associated with germline mutations in the DNA mismatch repair genes hMLH1 and hMSH2.
    • familial clustering with an autosomal dominant pattern of inheritance (hereditary ovarian cancer) results from germline mutations in putative tumor suppressor genes.
  • obesity is associated with hyperinsulinemia and increased risk of several cancers. Body mass is correlated with breast, colorectal, prostate, endometrial, and ovarian cancers.
  • tubal ligation lowers risk (RR 0.2-0.9) & this effect lasts ~20yrs presumably due to decreased ovarian blood supply
    • Ovarian Cancer Association Consortium (OCAC)study published in 2012 suggests patients with a history of endometriosis have:
      • 3x risk of clear-cell ovarian cancers
      • more than double the risk of endometrioid tumours
      • 2x risk of low-grade serous ovarian cancers
  • talcum powder applied to genital area theoretically may cause ovarian cancer but data is conflicting

germ cell tumours

  • account for 80% of ovarian neoplasms requiring surgery in adolescents

dermoid cysts

  • account for 50% are adnexal masses in pre-pubertal girls
  • 99% are benign
  • 10-20% are bilateral although may not be concurrently.

solid teratomas

  • usually malignant; 50% occur before age 20yrs, 98% are unilateral.
  • rarely hormonally active, although occasional one does produce hCG.

dysgerminomas

  • arise from undifferentiated germ cells and are always malignant.
  • usually occur before 20yrs age & may be bilateral, and may secrete hCG.

choriocarcinoma

  • very rare to arise without a pregnancy; highly malignant; secretes hCG.

gonadoblastomas

  • rare mixed germ cell & sex-cord tumor of prepubertal children
  • most patients are karyotypically 46XY or mosaic 45XO-46XY

endodermal sinus tumours

  • arise from the yolk sac endoderm
  • mostly seen in children & adolescents
  • highly malignant, metastazing early through lymphatics, poor prognosis.
  • virtually all secrete AFP which is used as a tumour marker

epithelial ovarian tumours

  • have potential to develop into cystadenocarcinoma
  • very uncommon in childhood and early adoloscence but account for 18% of ovarian neoplasms in late adolescence.

serous cystadenomas

  • are most frequent in 20-40yr olds

mucinous cystadenomas

  • most frequent in 30-50yr olds and usually > 15cm at diagnosis and may form tumours weighing more than 45kg. prone to torsion and adhesion formation.

endometrioid tumors

  • less common than cystadenomas; most frequent in 30-50yr olds and are usually malignant although with reasonable prognosis. May be cystic and up to 25cm.

gonadal stromal tumours (sex cord mesenchymal tumors)

  • often hormonally active

granulosa cell tumours

  • usually 5-10cm and generally solid but may undergo cystic degeneration if large.
  • may produce dub as they can produce excess oestrogen (25% do), and thus can cause endometrial hyperplasia or carcinoma, particularly in woman aged > 40yrs.
  • if malignant (25% are), late recurrence beyond 5yrs often occurs.
  • infrequent in children and when present are rarely malignant but occasionally produce precocious puberty.

thecoma fibromas

  • almost never malignant but almost always hormonally active
  • rarely occur before age 30yrs, and less common after menopause than granulosa cell tumours
  • luteoma - may produce oestrogen, androgen or be inert, and more likely to become malignant than thecoma fibromas

luteoma of pregnancy

  • occurs in 10-40% of pregnancies and is a benign solid tumour usually 5-10cm and occasionally produces testosterone causing mild maternal masculinisation during pregnancy and has been reported to cause masculinisation in the female fetus.
  • these regress post-partum leaving no residua.
  • NB. a solid ovarian tumour discovered during pregnancy should be surgically evaluated because of the possibility of ovarian cancer.

Sertoli-Leydig cell tumours

  • formerly called arrhenoblastomas or androblastomas
  • very rare; 25% are hormonally active; 3-20% are malignant.
neo_ovarian.txt · Last modified: 2016/02/25 07:56 (external edit)