A corpus luteum cyst is a type of functional ovarian cyst that forms after ovulation, when the structure that releases the egg fills with fluid or blood instead of breaking down normally. It is usually benign and part of the natural menstrual cycle.
Most corpus luteum cysts do not cause symptoms and often go away on their own within a few weeks or months. When symptoms do occur, they are usually mild but may include lower abdominal pain or discomfort.
In some cases, complications such as rupture or internal bleeding can occur and may require medical attention. Diagnosis is typically made with imaging tests, and treatment depends on symptoms and the size of the cyst.
Main symptoms
Many cases of a corpus luteum cyst are found incidentally and do not cause noticeable symptoms. When symptoms are present, they may include:
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Mild to moderate pain on one side of the lower abdomen
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Pelvic discomfort or a feeling of pressure
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Bloating or a sense of fullness
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Irregular menstrual cycles or delayed periods
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Pain during intercourse
Symptoms are usually mild, but sudden or severe pain may indicate a complication such as cyst rupture and requires prompt medical evaluation.
Possible causes
A corpus luteum cyst develops as part of the normal ovulation process. After an egg is released, the follicle transforms into the corpus luteum, which produces hormones, especially progesterone. If this structure fills with fluid or blood instead of shrinking, it can form a cyst.
Hormonal changes during the menstrual cycle can contribute to the formation of a corpus luteum cyst. It may also occur in early pregnancy, when the corpus luteum remains active. In some cases, minor bleeding inside the cyst can lead to what is known as a hemorrhagic cyst.
This condition is not transmitted and is not related to infections or sexual activity.
Confirming a diagnosis
A corpus luteum cyst is usually diagnosed with a pelvic ultrasound, which allows healthcare providers to assess its size, shape, and internal characteristics. The imaging often shows features that help distinguish it from other types of ovarian masses.
In some situations, additional tests such as pregnancy tests or blood work may be performed to rule out other conditions. Most cysts are monitored over time to ensure they resolve on their own.
Treatment options
Treatment for a corpus luteum cyst depends on its size, the presence of symptoms, and whether complications have developed.
According to the American College of Obstetricians and Gynecologists (ACOG), many functional ovarian cysts resolve spontaneously without treatment and can be safely monitored over time. Healthcare providers may recommend follow-up ultrasounds to monitor changes over time. This approach is commonly used for small or asymptomatic cysts.
Pain relievers may be used to manage discomfort associated with a corpus luteum cyst. In some cases, hormonal medications may be considered to help regulate the menstrual cycle.
Surgery is rarely required but may be considered if the cyst is large, persistent, or causing complications such as rupture or internal bleeding.
Possible complications
Although uncommon, a corpus luteum cyst can lead to complications. These include cyst rupture, which may cause sudden and severe pain, as well as internal bleeding. In rare cases, ovarian torsion can occur, where the ovary twists and reduces blood flow, requiring urgent medical care.
When to see a doctor
Medical evaluation is recommended if there is:
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Sudden or severe abdominal pain
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Dizziness or fainting
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Persistent pelvic discomfort
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Changes in menstrual patterns
Prompt medical evaluation helps identify possible complications of a corpus luteum cyst and ensures timely and appropriate treatment.