Leiomyosarcoma vs. Liposarcoma

leiomyosarcoma vs.liposarcoma
Both leiomyosarcoma (LMS) and liposarcoma are soft tissue sarcomas

Both leiomyosarcoma (LMS) and liposarcoma are soft tissue sarcomas. While LMS develops from the smooth muscle cells, liposarcoma develops from the fat cells.

What are sarcomas?

Sarcomas are rare cancerous tumors of the connective tissues that support and surround other body structures. All types of sarcomas share certain microscopic features and have similar symptoms. 

Sarcomas can affect both adults and children including infants. They account for about 15% of childhood cancers in the U.S. 

Two types of sarcomas

Sarcomas are divided into two main groups.

  1. Bone sarcomas: These start in the bones and include cancers such as osteosarcoma, multiple myeloma and Ewing’s sarcoma.
  2. Soft tissue sarcomas: These start in the soft tissues such as the muscles, fat, blood vessels, fibrous tissue, deep skin tissue and nerves. Over 50 types of soft tissue sarcomas have been identified to date. Some of them are adult fibrosarcoma, Kaposi sarcoma, angiosarcoma, leiomyosarcoma (LMS) and liposarcoma. Soft tissue sarcomas account for less than 1% of all types of cancer around the world.

What are the similarities and differences of leiomyosarcoma vs. liposarcoma?

While LMS and liposarcoma share similarities, there are also important differences between the two conditions.

LMS Liposarcoma
Definition LMS is a rare type of cancer that starts in the smooth muscles of the body, the involuntary muscles present in the hollow organs such as stomach, bowel, bladder, blood vessels and uterus. Liposarcoma, also called a lipomatous tumor, is a rare type of tumor that starts from the fatty tissue in the body.
Most common sites affected Most commonly seen in the abdomen. In women, it is also commonly seen in the uterus (uterine LMS). Can develop anywhere in the body, but it is most often seen in the abdomen and thigh and behind the knee.
Nature Highly aggressive and spreads rapidly in the body. Generally slow-growing, although some liposarcomas may grow rapidly.
Prevalence Accounts for 10%-20% of soft tissue sarcomas. It affects adults more often than children (about 20-30 children are diagnosed with LMS in the U.S. per year). LMS of the uterus affects around 6 per million people per year in the U.S. Accounts for about 18% of soft tissue sarcomas. Approximately 2,000 people are diagnosed with liposarcomas each year in the U.S. It is more common in men (most common in men who are 50-65 years of age) than women.

Symptoms may not appear initially when the tumor is small, and mainly depend on the site and size of the tumor. Symptoms may include:

  • Pain
  • Unintentional loss of weight 
  • Appetite loss
  • Bloating
  • Fatigue
  • Nausea and vomiting
  • Lump or mass under the skin

Uterine LMS may cause additional symptoms such as pain or pressure in the pelvis, change in bowel and bladder habits, abnormal vaginal discharge or bleeding.

May not cause any symptoms until the cancer is in the advanced stages. Some people may notice a visible lump under the skin, which is generally not painful at first. Symptoms depend upon the site of the tumor, and may include:

  • A new lump anywhere on the body or an existing lump that keeps growing
  • Pain or numbness around the lump
  • Fatigue
  • Constipation
  • Blood in stool or black/tarry stools
  • Blood in vomit
  • Abdominal pain/cramps
Diagnosis The doctor takes a detailed medical history of the patient and does a physical examination. They may order tests such as an X-ray, ultrasound, computed tomography (CT) scan, magnetic resonance imaging (MRI) scan, fine needle aspiration cytology (FNAC) or biopsy (collecting a small tumor sample and examining under the microscope). The doctor takes a detailed medical history of the patient and does a physical examination. They may order tests such as a CT scan, MRI scan, biopsy or an ultrasound.

Treatment may vary depending on several factors such as the site or size of the tumor, its aggressiveness, the patient’s general health and whether the tumor has spread to other sites in the body.

Treatment mainly involves surgery along with reconstructive surgery (if needed), radiation therapy and chemotherapy.

Treatment depends on factors such as the type of liposarcoma, where it is present in the body and whether it has spread.

Treatment mainly involves surgery, radiation therapy and chemotherapy. Sometimes, the doctor may give radiation therapy or chemotherapy before surgery to shrink the tumor and make it easier to remove.


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