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Leiomyosarcoma of Small Intestine

Last updated Dec. 2, 2018

Approved by: Maulik P. Purohit MD, MPH

Leiomyosarcoma of Small Intestine is a very rare and highly-malignant mesenchymal (non-epithelial) tumor.

What are the other Names for this Condition? (Also known as/Synonyms)

  • Leiomyosarcoma of Small Bowel
  • LMS of Small Intestine
  • Small Intestinal Leiomyosarcoma

What is Leiomyosarcoma of Small Intestine? (Definition/Background Information)

  • Leiomyosarcoma (LMS) is a rare type of connective tissue cancer, accounting for 5-10% of all soft tissue sarcomas (a type of cancer). It was once believed that leiomyosarcomas originated from small, benign, smooth muscle tumors, known as leiomyomas. The occurrence of a malignant tumor from a leiomyoma is now believed to be extremely rare
  • Leiomyosarcoma of Small Intestine is a very rare and highly-malignant mesenchymal (non-epithelial) tumor. The cause of formation of this small bowel tumor may be due to certain genetic abnormalities
  • No definitive risk factors are observed, though leiomyosarcomas are generally known to be associated with trauma to the region, high-dose radiation exposure, and poor immunity
  • Small tumors may be painless and asymptomatic, while advanced cases present unexplained weight loss, abdominal pain, and anemia. In case of a delayed diagnosis, metastasis of the leiomyosarcoma to other distant regions may occur
  • The treatment of choice for Small Intestinal Leiomyosarcoma is a surgical excision with clear margins followed by radiation therapy/chemotherapy. In case of spread of cancer to other regions, a combination of treatments may be considered by the healthcare provider
  • The prognosis depends upon a set of several factors including the stage of the tumor, extent of tumor spread, overall health of the patient, and many other factors. In general, the prognosis of Leiomyosarcoma of Small Intestine is poor; although, the prognosis is slightly improved with low-grade and lower mitotic activity tumors

Who gets Leiomyosarcoma of Small Intestine? (Age and Sex Distribution)

  • Leiomyosarcoma of Small Intestine is a very rare tumor that is observed in adults (age range 50-70 years); only about 2-3% of all small bowel malignancies are leiomyosarcomas
  • Both males and females are affected, although a slight male predominance is observed
  • All races and ethnic groups are at risk for the tumor

What are the Risk Factors for Leiomyosarcoma of Small Intestine? (Predisposing Factors)

The risk factors for Leiomyosarcoma of Small Intestine are not well-established. However, there are a few leading theories behind leiomyosarcoma (LMS) formation:

  • Trauma to the affected region
  • High-dose radiation exposure is believed to increase the risk for LMS formation
  • Certain inherited genetic traits are believed to increase the risk
  • Exposure to certain chemical agents, such as vinyl chloride, certain herbicides, and/or dioxins, may increase the risk
  • Immunocompromised patients infected by Epstein-Barr virus seem to be predisposed to LMS. The reason for this is not understood, yet there seems to be a definite correlation between the viral infection and the arising of multiple, synchronized leiomyosarcomas

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Leiomyosarcoma of Small Intestine? (Etiology)

The exact cause of development of Leiomyosarcoma of Small Intestine is unknown, but it may be due to certain genetic defects.

  • In general, it is known that cancers form when normal, healthy cells begin transforming into abnormal cells - these cancer cells grow and divide uncontrollably (and lose their ability to die), resulting in the formation of a mass or a tumor.
  • Many cancer types are caused by genetic mutations. These can occur, due to inherited mutations, or mutations that occur due to environmental factors 
  • The transformation of normally healthy cells into cancerous cells may be the result of genetic mutations. Mutations allow the cancer cells to grow and multiply uncontrollably to form new cancer cells
  • These tumors can invade nearby tissues and adjoining body organs, and even metastasize and spread to other regions of the body

What are the Signs and Symptoms of Leiomyosarcoma of Small Intestine?

Leiomyosarcoma of Small Intestine may present the following signs and symptoms:

  • Initially, small-sized tumors may be asymptomatic
  • The tumor may be located anywhere in the small bowel; most tumors are observed in the jejunum, some are noted in the ileum and fewer in the duodenum
  • Commonly observed symptoms for advanced cancer are abdominal pain and discomfort, unintended weight loss, and fatigue
  • The carcinomas can spread to other parts of the gastrointestinal tract
  • Large tumors may cause a pressure effect by compressing adjoining structures and organs
  • Large tumors may ulcerate and bleed and become painful; acute gastrointestinal bleeding may be present
  • This may result in anemia due to blood loss
  • Intussusception: When one part of the intestine pushes itself into another part of the intestine (telescoping), causing obstruction of the bowel
  • Involvement of lymph nodes may be noted

How is Leiomyosarcoma of Small Intestine Diagnosed?

A diagnosis of Leiomyosarcoma of Small Intestine may involve the following:

  • Complete evaluation of family (medical) history, along with a thorough physical examination
  • Stool sample analysis
  • X-ray of the abdomen and pelvic region
  • Barium enema X-ray
  • Endoscopy for tumors in the duodenum (upper part of the small intestine). Capsule endoscopy is an effective tool for observing the small intestine along its entire length
  • CT or MRI scan of the abdomen and pelvic region: CT scan with contrast or enteroclysis is a reliable procedure for diagnosing the tumor
  • Abdominal ultrasound scan
  • Upper GI endoscopy: An endoscopic procedure is performed using an instrument called an endoscope, which consists of a thin tube and a camera. Using this technique, the radiologist can have a thorough examination of the insides of the gastrointestinal tract
  • Screening colonoscopy: A typical colonoscopy involves using a thin, flexible tube (called a colonoscope), with an attached video camera, to view the colon and rectum. It may help view the ileal and jejunal portions too
  • Imaging studies, such as MRI scan, scintigraphy, and PET scan, may be performed to detect tumor invasion and metastasis
  • Tissue biopsy of the tumor:
    • A tissue biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
    • Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
    • Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, and very rarely, electron microscopic studies to assist in the diagnosis

Note: A differential diagnosis to eliminate other tumor types (such as gastrointestinal stromal tumor) is considered, before arriving at a definitive diagnosis.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Leiomyosarcoma of Small Intestine?

The complications of Leiomyosarcoma of Small Intestine may include the following:

  • Ulceration of the tumor can lead to secondary infections of bacteria and fungus
  • Compression of the underlying nerve, which can affect nerve function
  • Severe bleeding can result in iron-deficiency anemia
  • Perforation or rupture of the bowel
  • The tumor can metastasize to the local or distant lymph nodes
  • Metastasis to other body organs such as the liver and peritoneum (seen in 25-50% of the cases), lungs, stomach, abdominal cavity, etc.
  • Recurrence of the tumor following treatment
  • Side effects of chemotherapy (such as toxicity) and radiation
  • Damage to the muscles, vital nerves, and blood vessels, during surgery
  • Anastomotic leak; leakage of GI tract contents following surgical procedures, which can result in severe infection and even sepsis
  • Post-surgical infection at the wound site is a potential complication

How is Leiomyosarcoma of Small Intestine Treated?

The treatment of Leiomyosarcoma of Small Intestine usually involves surgery, which is primarily the first treatment option considered. It also includes a combination of radiation therapy and chemotherapy.

  • Endoscopy: (for tumors confined to the duodenum)
    • When the tumor is confined to the surface, then endoscopic mucosal/submucosal resection (or surgical removal via endoscopy) is undertaken
    • Individuals with tumors less than 2 cm in size affecting the submucosa, and showing no involvement of the lymph/vascular system, are candidates for endoscopic resection
  • Surgical removal of the entire tumor may be the preferred method of treatment (surgical or segmental resection). When the tumors are near the ampulla of Vater, pancreatic-duodenectomy may be required
  • Aggressive lymphadenectomy, or surgery to remove lymph nodes, is proposed when several lymph nodes are affected
  • If the tumor has metastasized, then a combination of chemotherapy, radiation therapy, and invasive procedures may be used to treat the tumor
  • Palliative care is provided for advanced cancer stages
  • Follow-up care with regular screening and check-ups are very important and encouraged

How can Leiomyosarcoma of Small Intestine be Prevented?

  • Current medical research has not established a method of preventing the formation of Leiomyosarcoma of Small Intestine
  • Regular medical screening at periodic intervals with blood tests, radiological scans, and physical examinations are mandatory for those who have been diagnosed with the tumor
  • Due to its metastasizing potential and chances of recurrence, often several years of active follow-up and vigilance is recommended

What is the Prognosis of Leiomyosarcoma of Small Intestine? (Outcomes/Resolutions)

  • The prognosis of Leiomyosarcoma of Small Intestine is generally poor in a majority of cases. The overall 5-year survival following diagnosis is about 28-48%
  • In general, the prognosis depends upon a set of several factors, which include: 
    • Stage of tumor: With lower-stage tumors, when the tumor is confined to site of origin, the prognosis is usually excellent with appropriate therapy. In higher-stage tumors, such as tumors with metastasis, the prognosis is poor
    • Overall health of the individual
    • Age of the individual: Older individuals generally have poorer prognosis than younger individuals
    • The size of the tumor: Individuals with small-sized tumors fare better than those with large-sized tumors
    • Level of cell (mitotic) activity; the higher the level of mitotic activity, the poorer is the prognosis
    • Grade of the tumor: Poorly-differentiated tumors (high-grade) have poorer prognosis than well-differentiated tumors (low-grade)
    • Individuals with bulky disease may have a poorer prognosis
    • Involvement of vital organs may complicate the condition
    • The surgical resectability of the tumor (meaning, if the tumor can be removed completely)
    • Whether the tumor is occurring for the first time, or is a recurrent tumor. Recurring tumors have worse prognosis compared to tumors that do not recur 
    • Response to treatment: Tumors that respond to treatment have better prognosis compared to tumors that do not respond to treatment; good response to treatment (surgery and/or chemotherapy/radiation therapy)
    • Progression of the condition makes the outcome worse
  • An early diagnosis and prompt treatment of the tumor generally yields better outcomes than a late diagnosis and delayed treatment
  • The combination chemotherapy drugs used, may have some severe side effects (such as cardio-toxicity). This chiefly impacts the elderly adults, or those who are already affected by other medical conditions. Tolerance to the chemotherapy sessions is a positive influencing factor

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Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: Dec. 2, 2018
Last updated: Dec. 2, 2018