Corpus Luteum and Hemorrhagic Cyst

Synonyms/Description

Functional cyst (corpus luteum)

No synonym for hemorrhagic cyst

Etiology

The corpus luteum (CL) is a transient structure formed as a result of ovulation, due to the midcycle luteinizing hormone surge from the pituitary gland. The CL is responsible for the production of progesterone, hence the term “functional cyst.” It is necessary for regulating menses and for maintaining a pregnancy until it develops the ability to make its own progesterone. If a pregnancy does not occur, the CL breaks down. It can, on occasion, undergo internal hemorrhage and develop into a hemorrhagic cyst. When such a cyst continues producing progesterone, it is a hemorrhagic corpus luteum. If progesterone synthesis ceases, but the cyst persists, then it is considered a hemorrhagic cyst. Hemorrhagic cysts can enlarge up to 5 cm or more, causing pain, and may occasionally rupture, resulting in a hemoperitoneum. The pain typically resolves within a few days, whereas the cyst may take 1 to 3 months to regress. Patients with symptomatic hemorrhagic cysts typically present with acute unilateral pelvic pain and have a complex-appearing lesion on ultrasound evaluation. Often they are asymptomatic and can be an incidental finding. The nonspecific and confusing sonographic appearance of the hemorrhagic corpus luteum and hemorrhagic cyst often results in misdiagnosis and unnecessary surgery.