Ovarian cysts are common, fluid-filled sacs that can develop on or within an ovary. These formations are often benign and frequently present without any noticeable symptoms. Many individuals discover they have an ovarian cyst incidentally during routine medical examinations or imaging for other conditions. When a cyst is detected, questions about its nature and size naturally arise, leading to concerns about its implications for health.
Understanding Ovarian Cyst Size
A 2.1 cm ovarian cyst is considered a small to medium-sized cyst. Ovarian cysts are measured in millimeters (mm) or centimeters (cm), and their significance is not solely determined by size. Functional cysts, the most common type, often measure less than 3 to 5 cm and resolve spontaneously. Cysts under 4 cm are usually benign and rarely cause symptoms.
Cysts ranging from 5 to 10 cm are considered medium-sized and may require closer monitoring. Cysts larger than 5 cm are considered large. While size is a factor, the cyst’s appearance on imaging, any associated symptoms, and the individual’s age also influence medical recommendations. Many small cysts, even those up to 4 cm, often disappear without intervention, especially in premenopausal women.
Common Types and Formation of Ovarian Cysts
Ovarian cysts frequently form as a natural part of the menstrual cycle and are known as functional cysts. There are two primary types of functional cysts: follicular cysts and corpus luteum cysts. Follicular cysts develop when an ovarian follicle, which contains an egg, fails to rupture and release the egg during ovulation, continuing to grow with fluid. These are the most common type and often resolve within one to three months.
Corpus luteum cysts form after ovulation, when the sac that released the egg does not shrink as expected but instead seals off and fills with fluid. These cysts typically grow to about 3 cm. Other benign cysts not related to the menstrual cycle include: Dermoid cysts (mature cystic teratomas) can contain various tissues like hair, skin, or fat. Endometriomas (“chocolate cysts”) occur in individuals with endometriosis, forming when endometrial-like tissue grows on the ovaries and fills with old blood. Cystadenomas, benign tumors, develop on the surface of the ovaries and are filled with watery or mucus-like fluid.
Symptoms and When to Consult a Doctor
Many ovarian cysts do not cause any symptoms and are discovered incidentally during routine medical examinations. When symptoms occur, they can include pelvic pain, which may be a dull ache or sharp pain in the lower abdomen, often on one side. Other symptoms include bloating, a feeling of fullness or pressure in the abdomen, and changes in menstrual periods, such as heavier, irregular, or lighter bleeding. Pain during sexual intercourse or difficulty with bowel movements can also be indicators.
It is important to seek medical attention for any persistent or concerning symptoms. Immediate medical evaluation is warranted for sudden, severe abdominal or pelvic pain, especially if accompanied by fever, nausea, or vomiting. Signs of shock, such as cold and clammy skin, rapid breathing, dizziness, or weakness, also require urgent care. These severe symptoms could indicate complications like a ruptured cyst or ovarian torsion, where the ovary twists, cutting off its blood supply.
Diagnosis and Management Approaches
Diagnosis of an ovarian cyst begins with a pelvic exam, where a healthcare provider may feel for swelling on the ovary. An ultrasound confirms the presence of a cyst, providing details on its location, size, and composition (fluid-filled or solid). Blood tests, such as a cancer antigen 125 (CA 125) test, may also be performed if there are concerns about malignancy, though elevated levels can also be due to non-cancerous conditions.
The management approach for ovarian cysts depends on several factors, including the cyst’s size, type, appearance, and whether it is causing symptoms. For small, asymptomatic cysts, especially functional ones, a “watchful waiting” approach is recommended. This involves monitoring the cyst with follow-up ultrasounds over a few weeks or months to see if it resolves on its own. Hormonal birth control may be prescribed to prevent new cysts from forming, though it does not shrink existing ones. Surgical removal may be considered if a cyst is large (over 5 to 6 cm), persistent, symptomatic, or has concerning features. Surgery can be performed using minimally invasive techniques, but a larger incision may be necessary for very large or complex cysts.