Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at April 14, 2016

Leiomyomas are neoplasms, also called fibroids or cysts, that occur in smooth muscle tissue. Uterine fibroids are common leiomyomas. Though almost always benign, or non-cancerous, they can still have symptoms that affect body function.


Definition & Facts

Leiomyomas occur in areas of smooth muscle tissue. They most commonly appear in the uterus, skin, gallbladder, and small intestines. Leiomyomas comprise over half of all masses found in the small intestine, ileum and jejunum. Leiomyomas in each of these locations may be asymptomatic, or may cause a change in the way that the organ functions.

Surgery is often performed to remove them, but they may grow back. Surgery is not recommended unless the symptoms are not easy to live with. It is not well-understood why some people get leiomyomas and others do not. Some cases are thought to be caused by genetic factors, but many others appear for reasons not yet understood by science.

Symptoms & Complaints

The symptoms of leiomyomas are very specific to the organ where they are found. Uterine fibroids are known to cause changes to the menstrual cycle of women who have them. These changes can include heavy periods, irregular periods, painful periods, and infertility.

In the gallbladder, leiomyomas can either impede digestion, causing pain when fatty or otherwise heavy foods are eaten. They can also increase stomach acid, causing acid reflux and heartburn. In the small intestine, similar digestion issues may occur when leiomyomas are present, as well as nausea when eating and loss of appetite. Skin leiomyomas are mostly painful if in constricting areas and can cause social and psychological stress if found in highly visible parts of the skin.


Little is known about the reasons that leiomyomas form. One genetic mutation linked to renal cell carcinoma has been found in some rare cases to cause leiomyomas and be hereditary. However, most of the cases are considered idiopathic. Possible causes have been hypothesized, based on autoimmune issues, hormonal imbalances, and environmental exposure to chemicals or foods that cause sensitivities. However, no clear link to a single cause or process has been found in medical studies.

Diagnosis & Tests

Diagnosis of leiomyomas depend on the location of the mass. If they are on the skin or just below the surface, diagnosis usually requires a physical examination by the doctor and a biopsy. Masses in areas like the uterus are best found with an ultrasound examination. Masses in the gastrointestinal tract or other internal areas may need a combination of exams, including X-ray, MRI, colonoscopy, and upper gastrointestinal series to first determine the presence and location of the leiomyomas.

From there, a biopsy must be taken to determine whether it is cancerous or benign. This can be done with a needle biopsy if the mass is easy to reach (the skin and uterus are good candidates for this with an ultrasound-guided approach for the uterus), or with laparoscopic surgery that is usually done as an outpatient procedure with twilight anesthesia.

In almost all cases, the diagnosis of a leiomyoma is considered the best result when a mass is found. Many of them are inert and mostly asymptomatic. When these are found, however, doctors will continue to watch them on a regular basis for changes and increases in numbers and locations. This is to ensure that they remain asymptomatic and benign.

Treatment & Therapy

Treatment for leiomyomas is completely dependent upon the kinds of symptoms that exist. For some, mitigating symptoms is a preferable route to invasive surgery, especially when the symptoms are nonexistent. As the size, location, and symptoms of each mass or series of masses are the key indicators as to the treatment, treatment involves a very individualized protocol. First, location must be determined as well as size and number. The doctor will want to see if the leiomyomas are growing and/or multiplying.

The symptoms are considered next, and whether they are bearable, or if management of them is a preferred alternative to surgery. Finally, the pros and cons of surgery and the handful of complications are weighed (e.g. metastasis of fibroids to other locations in the body is a rare side effect of removal surgery).

Uterine fibroids are often ignored if their only symptom is a heavy period, while hormonal interventions like birth control are used to try and control the severity of pain and duration of the menstrual cycle. In some cases, this is true until the woman decides she would like to conceive, and then a discussion of surgery might happen if she is concerned about infertility. In the case of intestinal or gallbladder leiomyomas, surgery is recommended if they become large and obstructive, cause unmanageable pain, or deteriorate the health due to malabsorption or lack of appetite and unexplained weight loss.

Prevention & Prophylaxis

Because so little is known about the origin of leiomyomas, there is little that has been proven to work as a preventative measure. Living well with healthy diet, regular exercise, stress management, and low exposure to chemicals are all important ways to try and stave off any complication to health.

In the case of uterine fibroids, there is some prophylaxis in monitoring the duration and predictability of menstrual cycles as sudden changes can indicate formations. Finally, regular physical examinations and open conversations about any changes to the body's functioning can also help find problems early.