Broad ligament fibroids are not inherently dangerous, but they carry unique risks that other fibroids don’t. Because they grow in the tissue fold between the uterus and the pelvic wall, they can press on the ureters (the tubes connecting your kidneys to your bladder), displace nearby organs, and create significant surgical challenges when removal is needed. They account for less than 1% of all fibroids, making them rare but clinically important when they do occur.
What Makes Broad Ligament Fibroids Different
Most fibroids grow within or on the surface of the uterus itself. Broad ligament fibroids grow in the sheet of tissue (the broad ligament) that drapes between the uterus and the pelvic sidewall. This location puts them in close contact with the ureters, blood vessels, and bowel in ways that typical uterine fibroids aren’t.
There are two types. “True” broad ligament fibroids originate from smooth muscle tissue within the ligament itself. “False” broad ligament fibroids start in the uterus but grow outward into the broad ligament while staying attached to the uterine wall. Both types are classified as FIGO Type 8, meaning they’re considered extrauterine. The distinction matters mainly to surgeons planning removal, since false broad ligament fibroids still have a blood supply from the uterus.
How They Affect Surrounding Organs
The primary danger of broad ligament fibroids comes from their location, not their biology. As they grow, they can compress or displace the ureter on that side. When a ureter is partially or fully blocked, urine backs up into the kidney, causing a condition called hydronephrosis. Symptoms include pain in the side or back that may radiate to the groin, painful or frequent urination, nausea, vomiting, and occasionally blood in the urine. Left untreated, this backup can scar the kidney and permanently reduce its function.
Large broad ligament fibroids also push on the bowel and bladder. In case reports of giant fibroids (those over 20 cm or weighing more than 3 kg), the mass displaced bowel loops upward into the upper abdomen and obscured the ovary on the affected side. Patients with fibroids this large typically experience constipation, abdominal distension, urinary retention, and irregular periods. Only a handful of giant broad ligament fibroids have been reported in the medical literature worldwide, so this extreme scenario is exceptionally rare.
Torsion: A Rare Emergency
When a broad ligament fibroid grows on a stalk (pedunculated), there’s a small risk of torsion, where the fibroid twists on its blood supply. This cuts off circulation and causes tissue death. Torsion of any pedunculated fibroid occurs in less than 0.25% of cases, but when it happens, it’s a surgical emergency.
The typical presentation is sudden, severe abdominal pain on one side, often accompanied by nausea, vomiting, fever, and a rapid heart rate. Because these symptoms overlap with ovarian torsion, appendicitis, and other acute conditions, torsion of a fibroid is notoriously difficult to diagnose before surgery. If you experience sudden, intense pelvic pain with a known fibroid, it warrants urgent evaluation.
Diagnosis Can Be Tricky
One of the more practical dangers of broad ligament fibroids is misdiagnosis. On ultrasound and even CT scans, they frequently mimic ovarian tumors or other adnexal masses. This can lead to unnecessary anxiety about cancer or inappropriate surgical planning.
MRI is the most reliable imaging tool for telling broad ligament fibroids apart from ovarian or tubal masses. Typical fibroids have a distinctive low signal on certain MRI sequences that solid malignant tumors don’t share. MRI can also reveal internal changes like degeneration or areas of poor blood flow within the fibroid. If your doctor suspects a broad ligament fibroid based on ultrasound, an MRI can usually confirm it and rule out something more concerning.
Complications During Pregnancy
Large fibroids of any type can complicate pregnancy, and broad ligament fibroids are no exception. Research on fibroids larger than 5 cm shows that women with large fibroids had a cesarean delivery rate of 41%, compared to about 15% in women without fibroids. The main reason was obstructed labor: the fibroid interfered with the baby’s descent through the birth canal or with cervical dilation.
Fibroids in certain locations also increase the risk of malpresentation (the baby settling into a position other than head-down), placental abruption, and preterm labor. That said, many women with fibroids, including large ones, deliver without major complications. In one study, preterm labor occurred in 7.3% of women with large fibroids, which was lower than rates reported by earlier researchers. The risk depends heavily on the fibroid’s size, its exact position relative to the uterine cavity, and whether it’s near the placenta.
Surgical Removal Carries Higher Risk
Removing a broad ligament fibroid is more complex than removing a standard uterine fibroid. The ureter runs along the pelvic sidewall just millimeters from where these fibroids sit, and the fibroid’s growth often distorts normal anatomy. In large pelvic surgeries overall, ureteral injury occurs in roughly 0.3% to 0.6% of procedures. Risk factors that increase those odds include obesity, previous pelvic surgery, adhesions, large masses, and significant bleeding during the operation.
For giant broad ligament fibroids, surgeons sometimes place stents in both ureters before the operation to make them easier to identify and protect. The bowel and bladder are also at risk when a large mass has displaced them from their normal position. Despite these challenges, experienced surgical teams routinely remove these fibroids successfully. The key is accurate preoperative imaging so the surgical team knows exactly what they’re working around.
Pseudo-Meigs Syndrome
In rare cases, large fibroids, including those involving the broad ligament, can trigger a condition called pseudo-Meigs syndrome. This involves fluid buildup in the abdomen (ascites) and around the lungs (pleural effusion), which can cause shortness of breath and abdominal swelling. It mimics what happens with certain ovarian tumors, which is why it’s called “pseudo.” The fluid resolves once the fibroid is removed. While alarming when it occurs, this complication is uncommon and not cancerous.
Are They Cancerous?
Broad ligament fibroids are benign. Like all uterine fibroids, they’re made of smooth muscle and connective tissue. The chance of any fibroid being a hidden cancer (leiomyosarcoma) is extremely low. The concern with broad ligament fibroids isn’t malignancy. It’s their location and the pressure they can exert on vital structures as they grow. Most small broad ligament fibroids cause no symptoms and require no treatment. Monitoring with periodic imaging is often all that’s needed unless the fibroid grows large enough to compress surrounding organs or cause pain.