The discovery of an enlarged ovary during a routine examination or imaging can be an immediate cause for concern. An ovary is typically about the size of an almond, but enlargement often means its volume has increased significantly, sometimes exceeding 10 cubic centimeters. While this finding prompts necessary medical investigation, it is important to understand that the vast majority of ovarian enlargements are not serious health issues. The cause can range from normal, temporary hormonal activity to conditions requiring close monitoring or intervention.
Common and Temporary Causes
The most frequent reasons for an ovary to become temporarily enlarged involve the normal functioning of the reproductive cycle. These are known as functional cysts, which are fluid-filled structures resulting from monthly ovulation. The two primary types are follicular cysts and corpus luteum cysts, which are part of the process of releasing an egg.
A follicular cyst develops when the fluid-filled sac, or follicle, fails to rupture and release the egg at mid-cycle. Instead, it continues to grow, often reaching a diameter larger than 2.5 centimeters before typically resolving on its own. Similarly, a corpus luteum cyst forms after the egg is released, if the remaining follicle seals up and fills with fluid instead of shrinking. These cysts produce hormones and generally disappear spontaneously within one to three menstrual cycles.
Certain benign conditions can also cause ovarian enlargement, such as endometriomas, which are cysts formed by endometrial tissue growing on the ovary. Endometriomas can become relatively large, up to 10 centimeters, but they are non-cancerous growths associated with endometriosis. Another temporary cause is the physiological swelling that occurs just before ovulation. Because these common enlargements are benign and often self-limiting, the initial response is typically observation.
Conditions Requiring Further Investigation
An enlarged ovary can signal conditions that need more immediate or detailed medical attention. Ovarian torsion is a surgical emergency where the ovary twists around the ligaments that hold it in place, cutting off its blood supply. This twisting causes sudden, severe pelvic pain often accompanied by nausea and vomiting, requiring immediate intervention to save the ovarian tissue.
Polycystic Ovary Syndrome (PCOS) is a condition where the ovaries are often enlarged due to a hormonal imbalance. The enlargement is caused by numerous small, underdeveloped follicles, sometimes exceeding 20 on a single ovary, contributing to an overall volume greater than 10 cc. Though not an immediate emergency, PCOS requires management due to its association with irregular periods and metabolic issues.
The most serious, though rare, concern is ovarian malignancy, which is more frequently associated with complex masses or masses found in post-menopausal individuals. A complex cyst contains solid components, thick walls, or internal partitions, distinguishing it from simple, fluid-filled functional cysts. Cysts exceeding 10 centimeters can also pose a higher risk of complications like rupture or torsion, necessitating closer monitoring or removal.
Diagnostic Procedures for Evaluation
A healthcare provider determines the cause of an ovarian enlargement through a combination of imaging and laboratory tests. Transvaginal ultrasound is the primary and most effective imaging tool, using sound waves to create detailed images of the ovary’s size, volume, and internal structure. This imaging helps classify the mass as simple (fluid-filled) or complex (containing solid or irregular features).
To assess for ovarian torsion, a specialized ultrasound technique called a Doppler flow study is performed to visualize blood flow within the ovary. The absence or reduction of flow within the ovarian vessels can indicate a twisting of the blood supply. Blood tests are also routinely used, including a pregnancy test, as a corpus luteum cyst can persist and enlarge during early gestation.
The serum tumor marker CA-125 is frequently measured, although its utility varies significantly depending on the patient’s age and menopausal status. While CA-125 levels can be elevated in ovarian cancer, they are also raised by many benign conditions, including endometriosis, uterine fibroids, and pelvic inflammatory disease. This test is interpreted alongside imaging findings and the patient’s overall clinical picture.
Treatment and Management Strategies
The confirmed diagnosis dictates the treatment plan, which often begins with “watchful waiting” for most simple, small ovarian cysts. This conservative approach involves monitoring the cyst with a follow-up ultrasound scan, typically scheduled within six to twelve weeks, to confirm that the mass is shrinking or has resolved completely. This strategy is preferred for asymptomatic, simple cysts, especially those under 10 centimeters, due to the high rate of spontaneous resolution.
Medical management is often employed for underlying hormonal conditions contributing to the enlargement, such as using hormonal contraceptives to suppress ovulation and prevent the formation of new functional cysts. For conditions like PCOS, treatment focuses on managing symptoms and associated metabolic risks with medications.
Surgical intervention, often performed minimally invasively via laparoscopy, is reserved for specific circumstances. This includes cases of ovarian torsion, cysts that are persistently large or causing severe symptoms, or those with highly suspicious features suggesting malignancy.