What Are Fibroids? Uterine fibroids are nodules of smooth muscle cells and fibrous connective tissue that form in the wall of the uterus. Fibroids have many names. You may see them referred to as leiomyoma, leiomyomata, and just myoma. These growths are non-cancerous and can grow in different portions of the uterine wall. The location and size of these benign growths can determine the associated symptoms, which include chronic pain and heavy bleeding. Some women may even become anemic (low blood counts). The development of uterine fibroids have no known risk factors other than being a female of reproductive age. Women of African descent have increased risk and are seen in as many as 50 percent. Incidentally, some investigators have shown that women who have had two or more live born children have one-half the risk of developing fibroids. Therefore, having children seems to be protective. Fibroids vary considerably in size from less than an inch wide to the width of a cantaloupe (10 inches or more). They can increase in size to that of a five-month pregnancy and can be easily detected, as the women may appear pregnant. Fibroids occur in different areas within the uterus. There are three primary sites of involvement called Subserosal, Submucosal and Intramural. Photo courtesy of SCVIR Subserosal fibroids: These fibroids occur just under the outer lining of the uterus and can give it a bulbous contour. They usually do not cause excessive bleeding but do frequently cause chronic pelvic pain. In addition, they can compress the urinary bladder causing urinary frequency or compress the lumbar and sacral nerve trunks giving low back and leg pain. They can grow off the uterus and become "pedunculated" or on a stalk. These are best seen with MRI. Intramural fibroids: These develop within the central muscular wall of the uterus known as the myometrium. This is the most common type and it increases the size of the uterus, giving rise to bulk symptoms, chronic pelvic pain, and heavy menstrual bleeding and lower back pain. Submucosal fibroids: These occur most infrequently but can be the most distressing. They are located just under the inner lining of the uterus known as the endometrium. When this lining sheds each month it causes menstruation. Fibroids here increase the surface area of the lining and cause heavy bleeding and severe crampy abdominal pain. Many women suffer from chronic blood loss and develop anemia.	© 1999 RadiologyNY designed by: