Ovarian cysts are collections of fluid or tissue inside the ovary. They are very common, usually in fertile women, although they can also occur after the menopause.
There are different classifications, although they are often divided into two groups according to their cause: cysts of functional cause and cysts of organic cause.
The most common of these are functional cysts, which manifest themselves as changes in the ovulation process. They are completely benign, very common and disappear on their own. We can distinguish between
Follicular cyst: One of the main functions of the ovary is to produce a small cyst, known as a follicle, which contains the egg. During ovulation, the follicle ruptures to release the egg. If the egg is not released, the follicle continues to grow and a follicular cyst is formed. The cyst resorbs spontaneously in subsequent cycles.
Corpus luteum cyst: The follicle ruptures at the moment of ovulation, which can cause a slight bleeding inside the follicle. This small haematoma usually resolves spontaneously in the following weeks.
The other type are organic cysts, which are caused by abnormal growth in some of the ovary's tissues and usually disappear on their own. They are classified according to their contents:
- Serous cystadenoma: contains a clear fluid.
- Mucinous cystadenoma: contains a dense, mucous fluid.
- Teratoma or dermoid cyst: contains fat, hair, teeth, bone, etc.
- Endometrioma: contains a dark and dense fluid, similar to chocolate, hence the name 'chocolate cyst'.
- Ovarian border cysts or ovarian cancers: their contents are heterogeneous, solid and fluid.
Ovarian cysts are diagnosed by gynaecological ultrasound, although sometimes it may be necessary to have an MRI or computed tomography scan to differentiate the type of cyst. Blood tests to look for specific markers can also help in the diagnosis.
In general, no specific treatment is needed as most of them cause only mild symptoms that go away on their own after 6 to 7 weeks. Surgery may be necessary if the symptoms persist or if the cysts cause bleeding or ovarian torsion. In this case, the cyst or even the entire ovary can be removed.
Contraceptive pills can help prevent the formation of functional cysts by preventing the follicles from growing.
- Knudsen UB, Tabor A, Mosgaard B, Andersen ES, Kjer JJ, Hahn-Pedersen S, Toftager-Larsen K, Mogensen O. Management of ovarian cysts. Acta Obstet Gynecol Scand. 2004 Nov;83(11):1012-21. doi:10.1111/j.0001-6349.2004.00607.x. PMID: 15488114.
- Doret M, Raudrant D. Functional ovarian cysts and the need to remove them. Eur J Obstet Gynecol Reprod Biol. 2001 Dec 10;100(1):1-4. doi: 10.1016/s0301-2115(01)00443-2. PMID: 11728647.
- Nowak-Psiorz I, Ciećwież SM, Brodowska A, Starczewski A. Treatment of ovarian endometrial cysts in the context of recurrence and fertility. Adv Clin Exp Med. 2019 Mar;28(3):407-413. doi: 10.17219/acem/90767. PMID: 30659784.
