An adnexal mass describes a lump or growth found near the uterus, typically discovered during a pelvic examination or imaging test. It is not a specific diagnosis but covers a broad spectrum of conditions. The vast majority of these masses are benign, meaning they are noncancerous, and may not require aggressive treatment. However, because they range from harmless fluid-filled cysts to malignant tumors, careful evaluation by a healthcare provider is necessary.
Defining the Adnexal Region and the Mass
The adnexal region refers to the structures connected to the side of the uterus. These structures include the ovaries, the fallopian tubes, and the surrounding ligaments and connective tissues.
An adnexal mass is any growth originating within this anatomical area. The mass can be fluid-filled (a cyst) or a solid collection of tissue (a tumor). Understanding the origin and composition of the mass is the first step in determining its nature and the necessary medical approach.
Classifying the Types of Adnexal Masses
Adnexal masses are primarily categorized based on their origin, with the ovaries being the most frequent source. In menstruating women, the most common types are functional ovarian cysts, which arise from the normal menstrual cycle. These include follicular cysts (when the follicle fails to rupture) and corpus luteum cysts (when the post-ovulation structure does not break down). These cysts are almost always benign and frequently disappear on their own within a few months.
Other common benign ovarian masses include endometriomas, which are cysts filled with old blood due to endometriosis, and mature cystic teratomas, also known as dermoid cysts. Dermoid cysts can contain various types of tissue, such as hair, fat, and teeth. While these masses do not resolve spontaneously, they are generally noncancerous.
Masses can also arise from non-ovarian structures. Examples include a hydrosalpinx (a fallopian tube blocked and distended with fluid), a tubo-ovarian abscess (a pus-filled mass from an infection), and uterine fibroids that grow outward from the uterus.
A potentially life-threatening cause is an ectopic pregnancy, where a fertilized egg implants outside the uterus, usually in the fallopian tube. This is a medical emergency that must be ruled out immediately in women of reproductive age. Malignant tumors, such as ovarian cancer, are the most serious cause. They are statistically the least common, especially in premenopausal women, but the risk is higher in postmenopausal women.
The Diagnostic Process
The initial investigation begins with a detailed medical history and physical examination to identify symptoms like persistent pelvic pain or bloating. Ectopic pregnancy is excluded early by checking the beta human chorionic gonadotropin (hCG) level in women of reproductive age.
Transvaginal ultrasonography is the primary tool for evaluating an adnexal mass. This imaging technique provides clear visualization, allowing the provider to assess its size, whether it is purely fluid-filled (simple) or contains solid components (complex), and to check for blood flow using Doppler technology. Features such as large size, solid areas, thick internal partitions, or fluid in the abdomen can raise suspicion for malignancy.
Blood tests for tumor markers are frequently used to assess malignancy risk. The most common marker is Cancer Antigen 125 (CA-125), often elevated in ovarian cancer. However, CA-125 is not definitive, as levels can also be high due to benign conditions like endometriosis, uterine fibroids, or pelvic inflammatory disease. If ultrasound findings and CA-125 levels are inconclusive or the mass is large, further imaging with a Computed Tomography (CT) scan or Magnetic Resonance Imaging (MRI) may be requested.
Management Approaches
Management depends on the patient’s age, symptoms, and the mass’s characteristics determined by the diagnostic workup. For many small, simple, fluid-filled cysts in premenopausal women, “watchful waiting” is the standard approach. This involves monitoring the mass with follow-up ultrasounds over a few months to confirm that it shrinks or resolves.
Medical management may involve using hormonal contraceptives to prevent the formation of new functional cysts. Benign conditions, such as endometriosis, may also be managed with medication to control symptoms.
Surgical intervention is reserved for masses causing acute symptoms, such as severe pain or ovarian torsion (twisting of the ovary), or those suspicious for malignancy. Surgery is also necessary for benign masses that are large, persistent, or continue to grow. The procedure is often performed using minimally invasive laparoscopy, but open surgery may be required for very large masses or when cancer is strongly suspected. Removal of the mass treats the condition and obtains a tissue sample for final pathological diagnosis.