Leiomyosarcoma Health Article

Definition

Leiomyosarcoma is cancer that consists of smooth muscle cells and small cell sarcoma tumor. The cancer begins in smooth muscle cells that grow uncontrollably and form tumors.

Description

Leiomyosarcomas can start in any organ that contains smooth muscle, but can be found in the walls of the stomach, large and small intestines, esophagus, uterus, or deep within the abdomen (retroperitoneal). But for perspective, smooth muscle cancers are quite rare: Less than 1% of all cancers are leiomyosarcomas. Very rarely, leiomyosarcomas begin in blood vessels or in the skin.

Most leiomyosarcomas are in the stomach. The second most common site is the small bowel, followed by the colon, rectum, and esophagus.

Demographics

Leiomyosarcomas do occur in the breast and uterus, but they are very rare. Uterine sarcomas comprise less than 1% of gynecological malignancies and 2% to 5% of all uterine malignancies. Of these numbers, leiomyosarcomas are found in only 0.1% of women of childbearing age who have tumors of the uterus. Less than 2% of tumors in women over age 60 who are undergoing hysterectomy are leiomyosarcomas.

Causes and symptoms

The exact causes of leiomyosarcoma are not known, but there are genetic and environmental risk factors associated with it. Certain inherited conditions that run in families may increase the risk of developing leiomyosarcoma. High-dose radiation exposure, such as radiotherapy used to treat other types of cancer, has also been linked to leiomyosarcoma. It is possible that exposure to certain chemical herbicides may increase the risk of developing sarcomas, but this association has not been proven.

Since leiomyosarcoma can occur in any location, the symptoms are different and depend on the site of the tumor. When leiomyosarcoma begins in an organ in the abdomen, such as the stomach or small bowel, the physician may be able to feel a large lump or mass when he examines the abdomen. When leiomyosarcoma affects a blood vessel, it may block the flow of blood to the body part supplied by the artery. Commonly occurring symptoms include:

• painless lump or mass
• painful swelling
• abdominal pain
• weight loss
• nausea and vomiting

Diagnosis

Some patients who have leiomyosarcomas may be visiting the doctor because they have discovered a lump or mass or swelling on a body part. Others have symptoms related to the internal organ that is affected by the leiomyosarcoma. For example, a tumor in the stomach may cause nausea, feelings of fullness, internal bleeding, and weight loss. The patient's doctor will take a detailed medical history to find out about the symptoms. The history is followed by a complete physical examination with special attention to the suspicious symptom or body part.

Depending on the location of the tumor, the doctor may order imaging studies such as x ray, computed tomography (CT) scan, and magnetic resonance imaging (MRI) to help determine the size, shape, and exact location of the tumor. A biopsy of the tumor is necessary to make the definitive diagnosis of leiomyosarcoma. The tissue sample is examined by a pathologist (specialist in the study of diseased tissue).

Types of biopsy

The type of biopsy done depends on the location of the tumor. For some small tumors, the doctor may perform an excisional biopsy, removing the entire tumor and a margin of surrounding normal tissue. Most often, the doctor will perform an incisional biopsy, a procedure that involves cutting out only a piece of the tumor that is used to determine its type and grade.

Treatment team

Patients with leiomyosarcoma are usually cared for by a multidisciplinary team of health professionals. The patient's family or primary care doctor may refer the patient to other specialists, such as surgeons and oncologists (specialists in cancer medicine), radiologic technicians, nurses, and laboratory technicians. Depending on the tumor location and treatment plan, patients may benefit from rehabilitation therapy with physical therapists and nutritional counseling from dieticians.