Uterine fibroids are common non-cancerous growths that develop in the muscular wall of the uterus. While many fibroids are contained within the uterine wall, a specific type known as a pedunculated fibroid is structurally unique. This configuration leads to distinct symptoms and complications that differ from other types of fibroids.
Defining the Pedunculated Fibroid
A fibroid is considered pedunculated when it is attached to the uterus by a narrow stem or stalk, called the pedicle. This pedicle contains the blood vessels that supply the growth, allowing the fibroid to hang freely either inside or outside the uterine cavity.
The location determines its specific classification. A pedunculated subserosal fibroid grows outward from the outer surface of the uterus, suspended into the pelvic or abdominal cavity by its stalk. Conversely, a pedunculated submucosal fibroid grows inward, protruding into the uterine cavity. The presence of the stalk grants the fibroid mobility, which affects the nature of the symptoms experienced.
Distinct Symptoms and Complications
The most specific complication associated with a pedunculated fibroid is the risk of torsion, or twisting, of its stalk. Since the fibroid is mobile, sudden movements can cause the pedicle to twist around itself, cutting off the blood supply to the mass. This condition is a medical emergency resulting in acute, severe abdominal pain because the fibroid tissue begins to die, a process known as ischemic necrosis or degeneration.
Symptoms depend heavily on the fibroid’s location. Pedunculated subserosal fibroids are found on the outside of the uterus and may grow large before causing symptoms, which usually involve pressure on nearby organs. They can cause pelvic fullness, bloating, or discomfort, and may press on the bladder or bowel. Their mobility can sometimes cause them to mimic other pelvic masses, such as an ovarian tumor, making diagnosis challenging.
Pedunculated submucosal fibroids project into the uterine cavity and are more likely to cause symptoms even when smaller. These growths are strongly associated with abnormal uterine bleeding, including heavy and prolonged menstrual periods, which can lead to anemia. They can also interfere with fertility by distorting the uterine lining or blocking the fallopian tubes.
Diagnosis and Differentiation
The initial step in diagnosing a pedunculated fibroid involves a pelvic examination, where a physician may feel an irregular contour or enlargement of the uterus, or a mass separate from the ovaries. Imaging studies are then employed to confirm the presence of a fibroid and determine its exact location and attachment. Transabdominal and transvaginal ultrasound are the first-line diagnostic tools because they are non-invasive and visualize the uterine structure.
Ultrasound measures the size and maps the location of the fibroid. Magnetic Resonance Imaging (MRI) offers greater detail, which is useful for differentiating a pedunculated subserosal fibroid from other pelvic masses, such as an ovarian cyst or tumor. MRI is highly effective at visualizing the stalk connecting the mass directly to the uterus. This detailed visualization is necessary when planning for surgical intervention.
Diagnosing a torsed fibroid can be challenging because the twisted pedicle may not be clearly visible on imaging tests. In cases of acute, severe pain, the diagnosis is often made based on the clinical presentation and confirmed during emergency surgery. Imaging features that suggest torsion include a lack of blood flow within the mass on Doppler ultrasound.
Treatment Approaches
The management of a pedunculated fibroid depends on whether it is causing symptoms, its size, and the patient’s desire for future fertility. Asymptomatic fibroids can often be managed with watchful waiting and periodic monitoring via ultrasound. If the fibroid is causing significant symptoms, such as heavy bleeding or persistent pressure, or if torsion has occurred, intervention is usually required.
Surgical removal, known as myomectomy, is often the definitive treatment for symptomatic pedunculated fibroids, as it preserves the uterus. For pedunculated subserosal fibroids, minimally invasive laparoscopic myomectomy is the preferred approach, where a surgeon can easily clip and cut the pedicle through small abdominal incisions. Pedunculated submucosal fibroids, which project into the uterine cavity, are typically removed using hysteroscopic myomectomy, where instruments are passed through the vagina and cervix without any external incisions.
Other non-surgical options may be considered, such as Uterine Artery Embolization (UAE), which involves blocking the blood supply to the fibroid to cause it to shrink. However, the choice of technique for a pedunculated fibroid is often guided by the need to efficiently and safely detach the mass at its narrow stalk. For torsed fibroids, immediate surgical intervention is mandatory to remove the necrotic tissue and prevent further complications like infection or gangrene.