Fibroids: Leiomyomas – Benign Muscle Tumors

Fibroids are benign muscle tumors. They are the most common gynecological pathology. They are treatable, although it is not always necessary.


Fibroids are diagnosed in 20 to 25% of women over the age of 30. They are generally non-cancerous muscle tumors of the uterus that may or may not produce signs and symptoms. Malignancy may occur in .2 to 1% of cases. Some women have small fibroids while others may develop fibroids that are as big as grapefruit. Pregnancy often causes fibroids to grow, a process that may be reversed after childbirth.

Types of Fibroids

Fibroids, also called leiomyomas, are classified into one of three categories, although a fibroid may become large enough to be classified in two or all of these categories.

Submucosal

Submucosal fibroids growth within the endometrial cavity, which is the inner cavity of the uterus, or impinge on the endometrium, the inner lining of the uterus that is shed during menstruation.

Intramural

Intramural fibroids grow in the muscular, middle layer of the uterus. They do not touch the endometrium or the outer layer of the uterus.

Subserosal

Subserosal fibroids occur in the outer, or subserosal layer of the uterus. They can cause bumps on the surface of the uterus or become pedunculated, becoming a growth that hangs off of the outside of the uterus.

Signs and Symptoms

When fibroids become large enough, any type of fibroid can cause pelvic pressure, pain, cramping, or urinary urgency and frequency. Submucosal fibroids can cause irregular bleeding ranging from mild spotting between periods to continuous, heavy bleeding. Fibroids growing on the backside of the uterus may cause back pain. Uterine position can affect symptoms as well. Women with uteruses that tip towards the back may experience back pain more so than women with uteruses that tip forward.

Diagnosis and Treatment

Pelvic ultrasound is used to diagnose fibroids. Due to the varying degree of size and density among fibroids, abdominal and transvaginal ultrasound are used. The size, location, and fibroid classification is determined. If fibroids are too dense for adequate ultrasound analysis, magnetic resonance imaging (MRI) may be used for further diagnosis.

Fibroids that do not cause significant problems are often closely watched with subsequent ultrasounds. Symptomatic fibroids may be surgically removed from the uterus, a procedure called a myomectomy. Hysterectomy, or removal of the uterus, may be another option when the uterus is mostly fibrotic. Uterine artery embolization (UAE) is a process in which the arteries supplying the fibroids with blood are blocked, causing the fibroids to shrink.