Uterine fibroids, also known as leiomyomas or myomas, are non-cancerous growths composed of muscle and connective tissue that develop in or on the uterus. They are a common occurrence, affecting a significant number of women, particularly during their reproductive years. While many individuals with fibroids experience no symptoms, others may encounter issues such as heavy menstrual bleeding, pelvic discomfort, or frequent urination. These growths can vary in size from microscopic to large masses that can enlarge the uterus.
Typical Locations of Fibroids
Fibroids are primarily categorized by their location within or on the uterine structure. Intramural fibroids are the most common type, growing directly within the muscular wall of the uterus. These fibroids can expand, potentially distorting the uterine cavity.
Submucosal fibroids develop just beneath the inner lining of the uterus and protrude into the uterine cavity. Even small submucosal fibroids can lead to significant bleeding and may affect fertility.
Subserosal fibroids form on the outer surface of the uterus, growing outwards into the pelvis. While smaller subserosal fibroids might not cause many symptoms, larger ones can exert pressure on nearby organs. Pedunculated fibroids are a variation of subserosal or submucosal fibroids, attached to the uterus by a slender stalk. The presence of a stalk can lead to sudden, sharp pain if the fibroid twists, cutting off its blood supply.
When Fibroids Grow Outside the Uterus
While most fibroids are found within or directly on the uterus, in rare instances, they can grow outside this typical location. Parasitic fibroids are one rare type, which can detach from the uterus and establish a new blood supply from other organs, such as the omentum or bowel.
Another uncommon condition is disseminated peritoneal leiomyomatosis (DPL), characterized by the appearance of multiple benign smooth muscle nodules on the surfaces of the peritoneum, the membrane lining the abdominal cavity. Intravenous leiomyomatosis (IVL) is a rare condition where benign smooth muscle tissue from the uterus grows into uterine veins. This growth can extend into larger veins, and in some exceptional cases, even reach the heart. A very rare condition, benign metastasizing leiomyoma (BML), involves benign fibroid cells spreading to distant organs, most commonly the lungs, but importantly, these cells retain their benign characteristics and do not become cancerous.
Recognizing and Diagnosing Fibroids
Fibroids, regardless of their location, can present with a range of symptoms, or sometimes no symptoms at all. Common indicators include heavy or prolonged menstrual bleeding, bleeding between periods, and pelvic cramping or pain. Individuals might also experience a feeling of fullness or pressure in the lower abdomen, frequent urination due to pressure on the bladder, or lower back pain.
Diagnosis often begins with a physical examination, where a healthcare provider may detect a firm, irregular mass during a pelvic exam. Imaging techniques are then employed to confirm the presence and characterize the fibroids. Ultrasound uses sound waves to image the uterus and identify fibroids. Magnetic Resonance Imaging (MRI) provides more detailed images and can help determine the size, number, and precise location of fibroids. In some cases, especially with extra-uterine fibroids, diagnosis may occur incidentally during imaging for other conditions or when symptoms become severe.
Treatment Options
Managing fibroids involves various approaches, tailored to the individual’s symptoms, fibroid characteristics, and desire for future fertility. For those with mild or no symptoms, a conservative approach known as watchful waiting may be recommended.
Medical therapies can help manage symptoms, with options such as hormonal treatments like gonadotropin-releasing hormone (GnRH) agonists that can temporarily shrink fibroids and reduce bleeding by lowering estrogen and progesterone levels. Other medications, including birth control pills, progestins, and non-steroidal anti-inflammatory drugs (NSAIDs), can alleviate heavy bleeding and pain but do not shrink the fibroids.
Surgical interventions offer more definitive solutions. Myomectomy involves the removal of fibroids while preserving the uterus, making it a suitable option for individuals who wish to maintain their fertility. Hysterectomy, the surgical removal of the uterus, provides a permanent solution by eliminating fibroids entirely, but it also ends the ability to conceive. Uterine artery embolization (UAE) is a minimally invasive procedure where small particles are injected to block the blood supply to the fibroids, causing them to shrink. This procedure preserves the uterus and can significantly reduce symptoms.