Ovarian cyst is a surgical, imaging, or examination finding of an enlarged, fluid-filled ovary or portion of ovarian tissue. Ovarian cysts imply a pathophysiological process involving the ovary itself.

Risk factors:

• pre-menopausal age group - Higher prevalence, risk of malignancy is lower, vast majority in this group are benign
• Early menarche
• 1st trimester of pregnancy
• personal history of infertility or PCOS
• Increased gonodrophin hormones
• Tamoxifen therapy
• Personal/family Hx of endometriosis

Ovarian cysts: types

Benign ovarian cysts are extremely common. They may be divided into physiological cysts, benign germ cell tumours, benign epithelial tumours and benign sex cord stromal tumours.

Physiological cysts (functional cysts)

Follicular cysts

• commonest type of ovarian cyst
  • especially in a women of reproductive age
• due to non-rupture of the dominant follicle or failure of atresia in a non-dominant follicle
• commonly regress after several menstrual cycles

Corpus luteum cyst

• during the menstrual cycle if pregnancy doesn't occur the corpus luteum usually breaks down and disappears. If this doesn't occur the corpus luteum may fill with blood or fluid and form a corpus luteal cyst