Submucosal fibroids are those that grow just beneath the endometrium or uterine lining. They can grow so large that they move the uterine lining out of place and can even develop a stalk. When this type of fibroid develops in this way, it is called a pedunculated submucosal fibroid.
In rare cases they can protrude into the vaginal canal. There was a report by the National Taiwan University Hospital of a woman with a submucosal fibroid that had inverted her uterus, and blocked her bladder and colon to the extent that she needed laxatives in order to move her bowels, and a catheter to remove urine from her body.
Submucosal fibroids cause a range of menstrual problems, including heavy bleeding, and bleeding in between periods. This is because they can increase the surface area of the uterine lining, meaning a larger area for blood to collect during the cycle.
Other types of bleeding disorder associated with submucosal fibroids include large blood clots and lengthy menstruation lasting seven days or longer. Sometimes the large clots can cause pain as they move through the cervix.
Since they are so close to the uterine lining, the uterus sees it as a foreign body that it needs to get rid of, so it will try to expel them by contracting. This causes severe cramps and pain, and some women have said it is as bad as labor pains.
They are a common cause of infertility, as their location can interfere with successful implantation, or cause miscarriages. A submucosal fibroid can also block a fallopian tube, and prevent sperm from reaching the egg. Doctors at the Wisconsin Fertility Institute found that women with submucosal fibroids had lower pregnancy rates than women with other types of fibroid.
A common treatment for submucosal fibroids is hysteroscopy, in which a thin tube and camera is inserted into the uterus via the cervix. It's becoming very popular in European countries such as Italy, where doctors are actually recommending immediate surgery for small fibroids instead of waiting to see if surgery is needed.
A study published by Tenon Hospital in France reported a woman who had developed a fever 18 weeks a Uterine Artery Embolization for a 5 cm submucosal fibroid. She also had pelvic pain and abnormal vaginal discharge. When they examined her, they found a fibroid comprised of dying tissue, which had developed a heavy growth of e.coli bacteria. They concluded that Uterine Artery Embolization was far too risky for submucosal fibroids.
I found many studies about the effectiveness of surgery on submucosal fibroids for improving the fertility. The RTI International-University of North Carolina reported that when women are treated for reasons other than symptom relief, such as when pregnancy is desired, weak evidence supports treating submucous fibroids via hysteroscopy.
It would seem that a hysteroscopy is only effective for relieving symptoms. But it's a risky procedure that can cause allergic reaction, infection, bleeding or the perforation of organs such as the uterus, bladder or colon. And, because a hysteroscopy does not address the root cause of the fibroid, it's likely to grow back anyway.