Corpus luteum cyst and haemorrhagic ovarian cyst

Definition

• When the corpus luteum fails to regress, a luteal cyst develops that may contain fluid or blood; the terms corpus luteum cyst and haemorrhagic corpus luteum are therefore often used synonymously.

Occurrence & epidemiology

Epidemiology

• In women of reproductive age most ovarian cysts are functional: dominant follicles, follicular cysts and luteal cysts.
• The corpus luteum is frequently seen on imaging in the second half of the cycle (luteal phase).

Aetiopathogenesis

Physiology

• After ovulation the dominant follicle collapses, and under the influence of LH the granulosa cells of the remaining follicular bed proliferate to form the corpus luteum.
• The corpus luteum produces mainly progesterone as well as inhibin A and oestradiol.
• In the absence of fertilisation its hormone secretion stops within 14 days of ovulation, and it regresses to a scar, the corpus albicans.

Clinical features

Cyst rupture and haemorrhage

• Ultrasound finding: After a cyst rupture, one finds free fluid in the pouch of Douglas and an inhomogeneous, partially collapsed structure on the ovary.

• Rupture of a corpus luteum is the most common cause of gynaecological haemoperitoneum, with or without active bleeding.

Diagnosis

• On CT the corpus luteum appears as a well-circumscribed unilocular (rarely bilocular) cystic structure up to 3 cm with a crenulated, briskly enhancing rim, corresponding to the ring of fire sign on colour Doppler.
• A 3 cm threshold has been suggested: follicles and corpus luteum lie below it, functional follicular and luteal cysts above it; on CT both cyst types usually measure less than 5 cm.
• After intravenous contrast the walls of luteal cysts appear thicker and more vascularised than those of follicular cysts.

Keep learning in the app

Further reading (selection)

1. StatPearls: Anatomy, Abdomen and Pelvis, Ovary Corpus Luteum (NCBI Bookshelf)
2. DocCheck Flexikon, Ovarialtorsion

Cross-references