Corpus luteum cyst is a type of ovarian cyst, which may rupture about the time of menstruation, and take up to 3 mo to disappear entirely.

• Corpus luteum cysts may contain blood and other fluids
• The physical shape of a corpus luteum cyst may appear as an enlargement of the ovary itself, rather than a distinct mass-like growth on the surface of the ovary
• Can grow to almost 10cm in diameter
• It has the potential to bleed into itself, or twist the ovary, causing pelvic or abdominal pain
• If it fills with blood, the cyst may rupture, causing internal bleeding and sharp pain. This pain disappears within a few days of the rupture

• It occurs after an egg has been released from a follicle. The follicle then becomes a secretory gland, called the corpus luteum
• If pregnancy doesn't occur, the corpus luteum usually breaks down and disappears
• It may however, fill with fluid or blood, causing the corpus luteum to expand into a cyst, and stay in the ovary
• Although it is cystic, it doesn't arise from benign corpus luteum cysts

• In women of reproductive age, cysts <5cm are common, and almost always physiological, rather than a cancer or other disease condition
• In postmenopausal women, the threshold is <1cm
• Rarely, it can cause the ovary to twist around the ovarian ligament and can cut off the blood flow to the ovary, called ovarian torsion, causing pain

• It rarely occurs at age 50+, because eggs are no longer being produced in menopausal women