Home Health A-Z Undifferentiated Pleomorphic Sarcoma: Causes, Symptoms and Treatment

Undifferentiated Pleomorphic Sarcoma: Causes, Symptoms and Treatment

Verified By Apollo Oncologist July 22, 2022 1271 0
Undifferentiated Pleomorphic Sarcoma
Undifferentiated pleomorphic sarcoma

Sarcoma is a rare kind of tumour that can develop on any organ or part of the body. It is an umbrella term for a wide variety of cancers that occur in the soft tissues. The sarcomas develop around tissues that connect or support different organs like muscles, tendons, blood vessels or the linings of joints.

What is undifferentiated pleomorphic sarcoma?

Undifferentiated pleomorphic sarcoma is a type of cancer that occurs in various soft tissues of the body. However, it generally occurs in the arms or legs. It may also occur in the posterior part of the abdomen or the retroperitoneum, but it is rare.

The term, pleomorphic is used as the cells of this sarcoma appear in multiple shapes and sizes under a microscope. They also tend to look very different from the body tissues where they develop.

Undifferentiated pleomorphic sarcoma was previously also known as malignant fibrous histiocytoma. This type of sarcoma can be extremely aggressive and may require immediate treatment to stop it from growing. 

What are symptoms of undifferentiated pleomorphic sarcoma?

The symptoms of undifferentiated pleomorphic sarcoma depend on its location (where it has grown) and the size of the lump. It generally affects the arms and legs but may occur in any part of the body. Some of the symptoms that may appear are:

  • Growing lump or swelling in the area affected
  • Pain, tingling or numbness where the cancer is growing
  • Loss of appetite
  • Diarrhea or constipation if it occurs in the abdominal region
  • Fever and chills
  • Unexpected weight loss
  • Pain in the bones 

What are the causes of undifferentiated pleomorphic sarcoma?

The  cause behind developing undifferentiated pleomorphic sarcoma is not yet known. However, there are certain factors that may increase your risk of developing this condition. These are:

  • Genetics: If either of your parents or relatives have a history of developing sarcomas, then you are at a greater risk of suffering from this condition. 
  • Age: This type of sarcoma generally affects 50 years or older people.
  • Previous treatment for cancer: If you have undergone radiation therapy or any other cancer treatment, then you may develop this type of sarcoma later.
  • Exposure to chemicals: Exposure to certain industrial chemicals like cleaning agents or herbicides may also increase your risk.

Many people who develop undifferentiated pleomorphic sarcoma have no known risk factors, and many people who have risk factors never develop cancer.

When do you need to see a doctor?

If you have undergone radiation or chemotherapy in the past, visit your doctor regularly for checks. Also, if you find a lump on your arms or legs or notice any of the signs mentioned above, notify your doctor immediately. For more information or consultation,

What are the treatment options for pleomorphic sarcoma?

Your doctor will select your treatment option based on the location and the size of the lump. The following options are available for the treatment of undifferentiated pleomorphic sarcoma:

  • Surgery: Surgery depends on the location of the sarcoma. If the sarcoma is in the arms or legs, the doctor will completely remove the sarcoma and a part of the healthy tissue to stop it from spreading. However, if cancer has spread widely, surgeons may have to amputate your arm or leg. Radiation therapy or chemotherapy may be performed before the surgery to shrink cancer and avoid amputations. 
  • Chemotherapy: If the sarcoma is spreading, your doctor may also subject you to chemotherapy. In chemotherapy, your doctor will prescribe various drugs to treat your cancer. These drugs work by killing the fast-growing cells to prevent the formation of sarcoma or tumors. Chemotherapy for undifferentiated pleomorphic sarcoma is usually prescribed if it recurs after the initial treatment.
  • Targeted drug therapy: Targeted drug therapies can help kill the cancer cells by focusing on specific abnormalities in the cells. Once the abnormalities are blocked, the cells will die on their own.
  • Radiation: In radiation therapy, high-intensity radiation beams are passed through the body to kill the cancer cells. This therapy can be performed as:
  • External beam radiation: In this procedure, a machine outside the body passes radiation beams to specific points to kill the cancer cells.
  • Intraoperative radiation therapy (IORT): This procedure is generally conducted after surgical removal of the sarcoma to kill the remaining cancer cells.
  • Immunotherapy: Immunotherapy is a specialized form of treatment that uses your body’s own immune system to fight cancer cells. Your immune system may not identify the cancer cells on its own due to certain chemicals the cells produce. However, by interfering with the process, your immune system can be made to attack these cells. 

What are the complications associated with this condition?

If left untreated, undifferentiated pleomorphic sarcoma may give rise to the following complications:

  • Severe pain in the area affected
  • Spreading of tumor to different parts of the body
  • Damage to the blood vessels
  • Pain, numbness or weakness in the body
  • Death

Apart from the sarcoma, certain complications may also occur due to the surgical resection or treatment of the sarcoma. They are:

  • Bleeding and infection
  • Damage to other vital organs of the body
  • Severe pain
  • Hair loss or weight loss due to chemotherapy 
  • Mental confusion 
  • Nausea and fatigue


Undifferentiated pleomorphic sarcomas are rare and cancerous. Surgical removal is the mainstay of treatment . Visit your doctor regularly after a diagnosis to ensure effective treatment. To know more about this condition, 

Frequently Asked Questions (FAQs)

Is undifferentiated pleomorphic sarcoma curable?

Overall survival rates 5 years after diagnosis are approximately 60 percent. Like all forms of cancer, early detection causes better outcomes. Tumours that are bigger than 10 centimetres, grow deep in the muscle and are high grade (most aggressive form) have highest risk for cancer spread.

How long does it take to recover from surgery after treating sarcomas?

It may take a few months to recover from surgical sarcoma removal. If you received chemotherapy, it might take even longer to recover.

Can undifferentiated pleomorphic sarcoma recur?

Yes. Although rare, there are chances that undifferentiated pleomorphic sarcoma may recur after surgery. Get yourself checked regularly to catch the sarcoma at its onset.

How is undifferentiated pleomorphic sarcoma diagnosed?

Your doctor will order several tests to diagnose sarcoma. They are:

Verified By Apollo Oncologist
Our dedicated team of experienced Oncologists verify the clinical content and provide medical review regularly to ensure that you receive is accurate, evidence-based and trustworthy cancer related information

Quick Appointment



Book ProHealth Book Appointment
Request A Call Back X