Corpus luteum cysts are masses that sometimes grow on the corpus luteum, a structure in your ovaries that makes important pregnancy hormones. You shouldn’t worry if your provider finds one during an imaging procedure. They’re harmless, painless, and usually go away without treatment.
A corpus luteum cyst is a normal, harmless, fluid-filled mass that forms in your ovaries. It grows on your corpus luteum, a group of cells that take shape after your ovary releases an egg (ovulation) each month. It has an important function during pregnancy.
Your corpus luteum produces a hormone called progesterone that your uterus needs to house a developing fetus. It breaks down when it’s no longer needed. A cyst forms when your corpus luteum keeps growing.
Anyone who menstruates can get a corpus luteum cyst, but your provider is more likely to find one if you’re pregnant because they last a little longer to support the pregnancy. They’re usually painless, so most people don’t even know they have a corpus luteum cyst. They often show up as part of routine imaging during pregnancy.
Corpus luteum cysts are often identified during imaging procedures in early pregnancy. They’re one of the most common types of cell growth (cysts, lumps, tumors) that doctors see during the first trimester.
Unless something goes wrong with your cyst, it shouldn’t affect your body. If you’re pregnant, it won’t affect the fetus either. In the extremely rare case that the cyst grows so big that it could harm your ovaries or pose risks to your pregnancy, your provider can remove it and give you exogenous progesterone to replace the progesterone made by the corpus luteum.
Small cysts don’t generally cause symptoms unless they rupture, they become hemorrhagic (bleed), or torsion (twisting) occurs. These conditions cause severe pelvic pain, severe nausea/vomiting or lightheadedness/weakness. You should be urgently evaluated if you have these symptoms.
A corpus luteum cyst forms in your ovaries when your corpus luteum keeps growing instead of breaking down, such as in pregnancy. Each menstrual cycle, a sac in one of your ovaries called a follicle creates and releases an egg. Soon after, your corpus luteum forms at the break of the follicle where the egg escaped. If the egg gets fertilized, your corpus luteum creates a hormone called progesterone that changes your uterus. Progesterone makes the lining of your uterus thicker so that a fertilized egg can take hold there. It creates a healthy environment inside your uterus where the egg becomes a fetus.
Your corpus luteum goes away when you don’t need the progesterone it’s making to support pregnancy. If you’re pregnant, your corpus luteum usually goes away around week 12, when the placenta starts making enough progesterone to keep the fetus healthy. If the egg doesn’t get fertilized, your corpus luteum usually goes away 10 days after the egg left your ovary.
You get a corpus luteum cyst when the corpus luteum fills with fluid and expands, but generally, it will self-resolve (reabsorb).
Your provider may do any of the following to find out if you have a corpus luteum cyst:
Chances are you won’t need treatment for a corpus luteum cyst. If you’re pregnant, your cyst will probably go away in your second trimester. If you’re not pregnant, your cyst may go away within a few weeks. Usually, by the time you have your third menstrual cycle, the cyst will be gone.
In the meantime, your provider can offer treatment to help you manage any symptoms. Your provider may recommend:
If your cyst gets so big that it could harm your ovary or pose risks if you’re pregnant, your provider may remove your cyst, but this is rarely needed.
You can’t prevent a corpus luteum cyst. They are normal and naturally form. A new corpus luteum forms each time you ovulate. And each time, there’s a chance a cyst can form. The good news is that this type of cyst isn’t one you should concern yourself with preventing. They’re harmless.
You shouldn’t expect a corpus luteum cyst to impact your life at all. Complications with these cysts can happen, but they’re rare.
You should seek immediate care if your cyst bursts and causes severe pain. Also, you should seek emergency care if it grows so big that it twists your ovary (ovarian torsion).
Get help right away if you notice these symptoms:
These warning signs are important. Keep in mind, though, that corpus luteum cysts are mostly uneventful masses that grow and disappear with no issues or impact.
Corpus luteum cysts usually go away without any treatment. If you’re pregnant, your corpus luteum cyst will probably go away on its own during your second trimester. If you’re not pregnant, your cyst will most likely break down a few weeks after ovulation.
Having a corpus luteum cyst doesn’t mean that you’re pregnant. Your doctor is more likely to find one if you’re pregnant, though, because they commonly show up during the imaging procedures that happen with pregnancy. Because these cysts often don’t cause symptoms, you may not know you have one until it shows up on an ultrasound.
A note from Cleveland Clinic
Don’t worry if your provider finds that you have a corpus luteum cyst. They’re harmless, and you probably won’t feel any symptoms letting you know it’s there. If your cyst is making you uncomfortable, your provider can help you manage symptoms until it goes away on its own.
Last reviewed by a Cleveland Clinic medical professional on 01/31/2022.
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