Ovarian cysts are fluid-filled sacs that can develop on or inside the ovaries. These growths are a common occurrence, affecting many individuals with ovaries at some point in their lives. While various types of ovarian cysts exist, the majority are harmless, do not produce symptoms, and often resolve without specific medical intervention. This discussion focuses specifically on simple ovarian cysts, which represent a significant portion of these benign formations.
Understanding Simple Ovarian Cysts
Simple ovarian cysts are fluid-filled sacs that develop on the ovary, characterized by smooth, thin walls and clear fluid content. The most common types of simple cysts are functional cysts, which arise as a normal part of the menstrual cycle.
Two primary types of functional cysts include follicular cysts and corpus luteum cysts. Follicular cysts form when a follicle, which is a small sac containing an egg, grows but fails to rupture and release the egg during ovulation. Instead, it continues to fill with fluid, forming a cyst. These cysts are typically larger than 2.5 cm.
Corpus luteum cysts develop after an egg has been released from its follicle. Following ovulation, the remaining follicle transforms into a structure called the corpus luteum, which produces hormones like progesterone. If the opening where the egg was released seals, or if the corpus luteum fills with fluid or blood instead of breaking down, a corpus luteum cyst forms. These cysts can also contain a small amount of blood.
Identifying Simple Ovarian Cysts
Simple ovarian cysts are frequently discovered incidentally during routine pelvic examinations or imaging performed for other reasons. This is because they often do not cause any noticeable symptoms. When symptoms do occur, they are typically mild and may include a dull ache or sharp pain in the pelvic area, a feeling of fullness or pressure in the abdomen, or bloating.
The primary method for diagnosing and characterizing ovarian cysts is a pelvic ultrasound. This imaging technique uses sound waves to create detailed images of the ovaries and uterus. A transvaginal ultrasound, which involves inserting a small probe into the vagina, often provides clearer and more detailed views of the pelvic organs.
Ultrasound helps determine if a cyst is “simple” by evaluating its characteristics. Simple cysts appear as well-defined, anechoic (fluid-filled with no internal echoes), unilocular (single compartment) structures with thin, smooth walls and no solid components or internal blood flow. These characteristics distinguish simple cysts from other ovarian masses.
Managing Simple Ovarian Cysts
For most simple ovarian cysts, the typical approach to management is watchful waiting. This involves monitoring the cyst over time without immediate medical intervention, as the majority of these cysts resolve on their own. Functional cysts, in particular, often disappear within one to three menstrual cycles, typically within 60 days.
Follow-up imaging, such as repeat ultrasounds, is commonly recommended to track the cyst’s size and appearance and to confirm its resolution. Simple ovarian cysts are almost always benign and do not become cancerous.
While most simple cysts follow a benign course, medical intervention, including surgery, may be considered in rare circumstances. These situations might arise if a cyst is very large (e.g., over 8-10 cm), causes significant and persistent symptoms, or is suspected of complications like torsion (twisting of the ovary) or rupture.